What does the research say?
A total of 30 people diagnosed with insomnia were randomly split into two groups and took CBD or an inactive pill (placebo) every night for two weeks. No difference was seen in insomnia severity, time to fall asleep or time spent awake at night; those taking CBD only reported feeling better overall. In a two-week study of 63 people with high levels of worry, 300 mg of CBD a day reduced sleep problems more than 50 mg, but the difference from the inactive pill was not significant. Two more positive results come from small or weakly designed studies: in an old 1981 study of 15 people with insomnia, those taking 160 mg of CBD said they slept longer; in 60 young people who clench their teeth in their sleep and have jaw muscle pain, a CBD gel applied inside the mouth to the chewing muscle every night for a month improved sleep scores more than placebo. However, this second result comes from a secondary publication of a pain study: the sleep measure was not in the study’s registration, and the CBD groups had worse sleep scores at the start. A 2025 review that pooled earlier studies concluded that pure CBD does not clearly improve sleep quality.
In a study of 28 healthy young adults, those who took 50 mg of CBD every night for 8 weeks saw their sleep questionnaire scores rise; but scores also rose in those taking placebo, and the difference between the two groups in the overall score was not shown statistically (there was a difference in favor of CBD only on the 'sleep quality' subscale). Sleep time measured at the wrist did not change. In a small study of scleroderma patients with an oil containing low doses of THC and CBD, the improvement in sleep quality was not significantly different from placebo. In an old sleep lab study of eight healthy volunteers, 15 mg of THC taken before bed did not change night sleep, but it caused sleepiness and weaker memory the next morning; when an equal amount of CBD was added to the THC, deep sleep decreased.
In small studies with THC-containing products, participants more consistently reported that their sleep improved; but some may have figured out which group they were in, which can make results look better than they are. In a one-night lab study of 20 people with insomnia, a single dose of THC and CBD together reduced total sleep by 24.5 minutes and dream sleep (REM) by 33.9 minutes; people’s sense of sleep quality did not change. In another study lasting two weeks, sleep time and sleep stages measured in the lab did not change. In reviews that pooled studies, the result depends on the type of measurement: sleep time measured with an electronic device got longer with cannabinoids in people with insomnia; in sleep lab studies, however, cannabis did not consistently change sleep stages, and the drop in REM was seen mostly in older, small studies with high THC doses. A 2026 Cochrane review (9 studies, 537 people) reported that medical cannabis adds little or nothing meaningful to sleep quality, total sleep and daytime functioning, and that it may increase side effects; the evidence is of very low or low certainty. Another review published the same year, pooling 10 studies, reported that cannabinoids clearly reduced insomnia; the summary of this review does not grade the certainty of the evidence. Among 42 people who wanted a medical cannabis card for insomnia, those who got the card right away reported fewer insomnia symptoms after 12 weeks than those who waited; but participants knew their group, and across all participants in the same study (most of whom had applied for pain, anxiety or depression), cannabis use disorder developed about twice as often in those who got a card. In two studies in Thailand with a traditional blend containing cannabis leaf and with a cannabis oil, sleep quality improved over four weeks about as much as in those taking lorazepam, a common sleep medicine: one was a double-blind study testing whether it was not worse than lorazepam; the other was a 60-person, open-label, unregistered study, and no difference was found between the groups. Neither study had an inactive pill group; how much of the improvement came from the product cannot be known. In an online study of 620 people, a supplement containing very little THC plus plants such as valerian and hops reduced sleep problems slightly more than placebo; a second formula containing more THC did not differ from placebo. The product company funded the study, and it is not known which ingredient the effect came from.
Placebo-controlled studies with CBN, another substance in cannabis, have mixed results. In an online company study of 1,020 people, all CBN doses reduced sleep disturbance slightly more than placebo, but did not differ from melatonin. In another study of 293 people, there was no significant difference in sleep quality, the main measure; the number of night awakenings went down, and adding CBD to CBN gave no extra benefit. In a one-night lab study of people with insomnia, CBN did not shorten time spent awake at night. In a study of veterans with sleep problems, another cannabinoid called CBG also did not differ from an inactive pill. Nabilone, a synthetic drug similar to THC, gave better sleep than an antidepressant (amitriptyline) over two weeks in fibromyalgia patients with insomnia; in Parkinson’s patients who stopped nabilone and switched to placebo, sleep problems got worse. One of these two studies had no placebo group, and in the other the finding comes from an analysis done afterward. Some of these studies were run or supported by companies that make the products.
Sleep apnea is when breathing repeatedly stops or becomes shallow during sleep. In a 73-person, six-week, placebo-controlled study with dronabinol, the synthetic form of THC, the number of breathing pauses per hour was about 11–13 lower in those taking dronabinol than with placebo, and at the high dose daytime sleepiness decreased slightly; but sleep structure, night oxygen levels and a test of staying awake did not change. Part of the difference comes from apnea counts rising in the placebo group: according to the results in the study registry, among those who completed the study, apnea counts fell by 2–5 per hour with dronabinol and rose by 8 with placebo. According to the same registry, 17 of 27 people on the high dose reported sleepiness, while no one on placebo did. In the first 17-person study, which had no control group, apnea counts also fell over three weeks. In a 9-person placebo-controlled study combining dronabinol with acetazolamide, apnea counts also fell; but acetazolamide is itself a drug that reduces apnea, and each dose was tried for only one week. In a 15-person open-label study combining it with atomoxetine, there was no improvement in the main measure; side effects such as excessive suspiciousness (paranoia) and, in one person, suicidal thoughts were seen, and a third of patients did not finish the study (according to the study registry, side effects were also common in the first week on atomoxetine alone), and the authors advised against using this combination for now. The American Academy of Sleep Medicine recommends that medical cannabis and its synthetic extracts not be used for sleep apnea because the evidence is insufficient; a 2024 systematic review also stressed that there are no long-term data. No study of CBD in sleep apnea was found. These studies do not show that a cannabis product can be used in place of treatments your doctor recommends, such as CPAP. A four-week, placebo-controlled study of the dronabinol and acetazolamide combination in 121 people ended in July 2025; the manufacturer announced in a press release that the first results were positive, but as of October 2026 the results had not been published in a peer-reviewed journal or in the study registry.
Restless legs syndrome is a condition with an urge to move the legs, especially when resting in the evening and at night, that disrupts sleep. The only controlled data with cannabinoids are from an analysis done afterward of a CBD study in Parkinson’s patients: in 18 patients, there was no difference in symptom severity between CBD and placebo. In a three-month study without a control group of 18 people, most of them with multiple sclerosis, symptoms eased and time awake at night got shorter with low-dose THC and CBD. There are also case reports describing symptoms going away in a few patients who used cannabis. A 2026 review wrote that no recommendation can be made without controlled studies; the guideline of the German sleep and neurology societies also does not recommend treatment with cannabinoids. As of October 2026, two placebo-controlled studies with CBD and cannabis oil are ongoing or about to start.
In Parkinson’s patients who act out their dreams (REM sleep behavior disorder), a 33-person placebo-controlled study found that CBD did not reduce the number of nights these behaviors occurred; an old case series of four patients had reported a decrease. The Brazilian Academy of Neurology’s 2025 Parkinson’s guideline, based on the placebo-controlled study, also states that CBD does not clearly affect how often these behaviors occur and does not list CBD among the treatments it recommends. In a 10-week placebo-controlled study of 171 people with post-traumatic stress disorder (PTSD) and recurring nightmares, dronabinol taken before bed reduced how often and how severe nightmares were more than placebo; a small improvement in the sleep quality score was also seen (additional analysis). However, most people taking dronabinol figured out which group they were in, the study was supported by the manufacturer, and there is no second large study confirming it. In a small study of 10 soldiers, nabilone also reduced nightmares. The American Academy of Sleep Medicine lists nabilone among the options that 'may be used' for PTSD-related nightmares, and writes that there is not enough evidence to make a recommendation for cannabis. Details of these studies are on the PTSD page; sleep problems in cancer patients are covered on their own page.
Strength of evidence: ●●○○ Weak evidence. Finding: No effect found. What does this mean?
Ongoing research on this topic
Trials testing CBD for this topic on ClinicalTrials.gov: 9 under way (4 recruiting); results are awaited from 2 that ended in the last two years. A trial being under way does not show that CBD works.
- NCT05840822: Phase 3, active, not recruiting, target 519 participants
- NCT07552974: Phase 2/3, not yet recruiting, target 100 participants
- NCT06290063: Phase 2, recruiting, target 385 participants
Possible side effects and drug interactions
In the insomnia study with pure CBD, dry mouth was reported; daytime mental performance was not impaired. When THC and CBD were taken together, mild sleepiness was seen the next day. In pain studies, dizziness, drowsiness, dry mouth, tiredness and nausea were more common with cannabis products, most of which contained THC. In sleep apnea studies, sleepiness was common with dronabinol; when combined with other drugs, side effects such as tingling in the fingers, nausea and suspiciousness were also reported.
CBD can slow down how the body breaks down some medicines; for example, blood levels of a drug called clobazam rose clearly. When used together with sleep medicines or sedatives, sleepiness may increase and drug levels may rise.
Interactions with medicines used for this condition
Interactions reported for these medicines in peer-reviewed publications and official prescribing information. A medicine that is not listed can still interact with CBD; tell your doctor about every medicine you take.
| Medicine | Importance | Warning | Source |
|---|---|---|---|
| Other benzodiazepines (lorazepam, etc.) | Caution | Benzodiazepines, sleep medicines and sedatives: Drowsiness and sedation may increase together with CBD. Talk to your doctor before using them together. | DailyMed Epidiolex label 7.4, EMA Epidyolex SmPC 4.4 |
To check interactions with the medicines you take: CBD drug interaction checker.
How was CBD used in studies?
In pure CBD studies, the dose ranged from 15 to 300 mg (study dose; not a personal recommendation), taken at night or as a single dose; in the insomnia study, CBD was dropped under the tongue before bed. With THC-containing products, about 2–15 mg of THC with 3–22.5 mg of CBD a day (study dose; not a personal recommendation), or a single dose of 10 mg of THC with 200 mg of CBD (study dose; not a personal recommendation), was used. Durations were mostly between one night and four weeks (the longest controlled studies lasted 8–14 weeks). In sleep apnea studies, dronabinol was used at 2.5–10 mg before bed (alone or together with another drug) (study dose; not a personal recommendation).
Study details (for health professionals)
Pure CBD has not clearly shown an effect on insomnia in controlled studies: in the most recent meta-analysis, CBD alone did not significantly improve sleep quality compared with placebo (SMD 0.13). In primary insomnia, 150 mg of CBD at night for 2 weeks did not change insomnia severity, time to fall asleep or night awakenings; in healthy people, a single 300 mg dose did not change sleep structure. With THC-containing products, subjective improvement is more consistent; objective measures, however, diverge by type of measurement: in a single-dose pilot lab study, THC/CBD reduced total sleep and REM sleep, in a two-week study polysomnography did not change, and in one meta-analysis sleep time measured with an electronic device got longer. According to a review pooling polysomnography studies, the drop in REM comes mostly from older, small studies with high THC doses. In the 2026 Cochrane review (9 RCTs, 537 people), medical cannabis adds little or nothing meaningful to sleep quality, total sleep and daytime functioning (very low certainty); side effects may increase (low certainty). In healthy young people, 50 mg/day of CBD for 8 weeks raised the questionnaire sleep score, but superiority over placebo on the overall score was not shown (there was a difference on only one subscale); sleep time measured at the wrist did not change (28 people); in systemic sclerosis, a low-dose THC+CBD oil made no significant difference in sleep quality. Studies added in October 2026 did not change the picture for pure CBD: in people with high levels of worry, 300 mg of CBD for 2 weeks did not differ from placebo for sleep problems; two positive findings come from small or weakly designed studies (in 1981, longer sleep reported with 160 mg in 15 people with insomnia; in 60 young people who clench their teeth in their sleep, PSQI improved with a CBD gel applied inside the mouth to the chewing muscle: a secondary publication of a pain trial, the sleep measure is not in the study’s registration, and the CBD groups had worse starting scores). With THC-containing products, insomnia patients who got a cannabis card right away had insomnia scores on average 2.9 points lower than those who waited over the 12-week period (participants knew their group; cannabis use disorder rose across the whole sample); in Thailand, with a traditional blend containing cannabis leaf and with a cannabis oil, sleep quality improved over 4 weeks about as much as in those taking lorazepam (one a double-blind study testing whether it was not worse than lorazepam, the other a small open-label study that did not test equivalence; neither had a placebo); a supplement containing very little THC and plant ingredients reduced sleep disturbance slightly more than placebo in an online 620-person RCT (company study); in healthy volunteers, 15 mg of THC taken at bedtime caused sleepiness and weaker memory the next morning. Nabilone was better than amitriptyline in fibromyalgia patients with insomnia (no placebo); CBG did not differ from placebo in veterans with sleep problems. A 2026 meta-analysis (10 RCTs, 2,134 people) reported a positive pooled result, while Cochrane rated the evidence as very low certainty; the Brazilian Sleep Association’s 2023 guideline does not recommend cannabis, CBD or THC for insomnia. In sleep apnea, dronabinol reduced breathing pauses in a 73-person, 6-week RCT and in a 9-person crossover study combined with acetazolamide (in the large study, 11–13 events per hour fewer than placebo; part of the difference comes from a rise in the placebo group), but sleep structure and oxygen levels did not change; in the open-label study combining it with atomoxetine, the main measure was negative; the studies are short and side effects common; the American Academy of Sleep Medicine’s 2018 position statement recommends against its use; there are no CBD data. In REM sleep behavior disorder (acting out dreams) in Parkinson’s patients, CBD did not differ from placebo on the primary measures in a 33-person RCT; the Brazilian Academy of Neurology’s 2025 Parkinson’s guideline, based on this study, also states that CBD does not clearly affect how often these behaviors occur and does not list CBD among the treatments it recommends. In restless legs, the only controlled data are a negative analysis done afterward (18 people); an 18-person open-label THC+CBD study is positive; the German guideline does not recommend it. In PTSD-related nightmares, a 171-person multicenter dronabinol RCT and a 10-person nabilone RCT are positive (the large study is the only one and was manufacturer-supported; most people taking dronabinol figured out which group they were in); the American Academy of Sleep Medicine lists nabilone among the options that 'may be used' for these nightmares. The studies are small and short (1 night–14 weeks in controlled studies). October 2026 search (PubMed, Cochrane, ClinicalTrials.gov): the table includes 29 controlled studies with cannabinoids on this topic, 6 studies without a control group or whose control could not be verified and 1 patient registry, 8 systematic or scoping reviews, and 4 guidelines or position statements. Additional publications of the same trials are in the 'other source' section of the relevant row; pain, Parkinson’s, MS and epilepsy trials in which sleep was only a secondary measure, 1970s sleep EEG studies of a few people each, and older reviews answering the same question were not included in the table (the reviews pooling them are in the table). Completed studies whose results have not been published in a peer-reviewed journal (e.g., a 121-person dronabinol combination study in sleep apnea, a 208-person CBD study in insomnia) and ongoing studies (e.g., a 519-person CBD insomnia study) are not in the table.
Evidence assessment: Weak / inconsistent (pure CBD — insomnia); no pure CBD data in sleep apnea; in restless legs, the only controlled data (a small analysis done afterward) are negative
CBD alone
Pure CBD did not significantly improve sleep quality compared with placebo (meta-analysis SMD 0.13; 95% CI −0.38 to 0.65); in newer studies too, 300 mg of CBD for 2 weeks in worried people did not differ from placebo. Positive findings come from small or weakly designed studies: in a 1981 study of 15 people, longer sleep was reported with 160 mg; in 60 young people who clench their teeth in their sleep, sleep scores improved with a CBD gel applied inside the mouth to the chewing muscle (a secondary publication of a pain trial; the sleep measure was not in the study’s registration and the CBD groups had worse starting scores). There is no CBD study in sleep apnea; in restless legs and REM sleep behavior disorder, the only controlled data are negative.
Products containing THC
With THC-containing formulas, subjective sleep is better (meta-analysis SMD 0.82), but measured sleep differs by type of measurement: in a single-dose lab study total sleep and REM decreased, in a two-week study the lab measurement did not change, and in one meta-analysis sleep time measured with an electronic device got longer; according to Cochrane 2026, medical cannabis adds little or nothing meaningful to sleep quality and total sleep (very low certainty); in people who got a medical cannabis card for insomnia, insomnia scores fell over 12 weeks, but participants knew their group, and in the same study cannabis use disorder developed about twice as often in those who got a card (most in those who applied for anxiety or depression); in sleep apnea, dronabinol reduced breathing pauses in short RCTs (11–13 events per hour fewer than placebo in 73 people; part of the difference comes from a rise in the placebo group), but the American Academy of Sleep Medicine recommends against its use; in PTSD-related nightmares, a 171-person dronabinol RCT found nightmares decreased more than with placebo (most people taking dronabinol figured out which group they were in); THC’s addiction and driving risks are separate.
Evidence: Weak (small RCTs, blinding problems, mostly subjective measures); CBN: very low/low; dronabinol in sleep apnea: low (two small and short RCTs, one combined with acetazolamide; the American Academy of Sleep Medicine does not recommend it); THC+CBD in restless legs: very low (a single uncontrolled study); dronabinol and nabilone in PTSD-related nightmares: moderate (same assessment as the PTSD page: a single large 171-person RCT and a 10-person RCT are positive; the large study was manufacturer-supported, and most people taking dronabinol figured out which group they were in)
Dose range in studies
In pure CBD studies, 15–300 mg (at night or as a single dose), 50 mg/day for 8 weeks; with THC-containing products, ~2–20 mg THC + ~0.5–22.5 mg CBD/day (plus 1–2 mg CBN in ZTL-101) or a single dose of 10 mg THC + 200 mg CBD; CBN 15–300 mg; nabilone 0.25–1.75 mg/day (0.5–1 mg in insomnia; at most 3 mg for PTSD nightmares); CBG 25–50 mg/day; dronabinol in sleep apnea 2.5–10 mg (alone or with acetazolamide or atomoxetine); dronabinol for PTSD nightmares 2.5–15 mg/day; in other THC-containing products, from very-low-dose supplements (0.35–0.85 mg THC) up to 30 mg THC in an old study; in one patient registry the THC dose rose clearly over time (observational; the authors write it may be a sign of tolerance)
Starting dose and titration
Fixed dose in most studies; in Ried 2023, increase from 0.2 → 1.5 mL/day; in de Almeida 2021, 75 → 300 mg/day; in sleep apnea, weekly 2.5 → 5 → 10 mg dronabinol in Prasad 2013, in Carley 2018 the 10 mg group started with 2.5 and 5 mg in the first two weeks, in Messineo 2023 weekly 2.5 → 5 → 10 mg together with atomoxetine; in Emerson 2026, CBG 25 → 50 mg after 2 weeks
These are doses researchers gave under medical supervision; they are not a recommended dose for you. "mg/kg/day" means milligrams per kilogram of body weight per day.
| Study | Participants | Product | Dose and titration | Duration | Result | Source |
|---|---|---|---|---|---|---|
| Linares 2018 (sleep) Double-blind, crossover RCT | 27 (1 left) Healthy volunteers | Pure CBD (oral) | 300 mg single dose, 30 min before polysomnography None | 1 night/arm | No significant effect on the sleep-wake cycle. 4 of 8 authors are inventors on a patent for a CBD derivative (fluorinated CBD); the university has an agreement with a drug company (Prati-Donaduzzi) to develop a synthetic CBD product for epilepsy, schizophrenia, Parkinson’s and anxiety disorders; 3 authors are medical advisers to a CBD supplier company (BSPG-Pharm); the manufacturer (STI-Pharm) supplied the CBD free of charge Side effects: Not reported (no difference on cognitive/subjective measures) | PMID 29674967, doi:10.3389/fphar.2018.00315 |
| Narayan 2024 (JCSM) Parallel RCT, 1-week single-blind placebo run-in (8 people who responded to placebo during the run-in were removed before randomization) | 34 randomized (18 CBD / 16 placebo); 32 completed; per the registered plan, 30 people were analyzed (15 CBD / 15 placebo) Moderate-severe primary insomnia | CBD, sublingual | 150 mg, 60 min before bed None (fixed) | 2 weeks | No difference in insomnia severity (ISI), falling asleep or nighttime wakefulness (WASO); well-being improved, actigraphic sleep efficiency rose at week 2. In the second publication of the same trial (Narayan 2025), daytime cognitive performance (attention, executive function, memory) was not affected; those taking CBD reported feeling calmer and more clear-headed in the mornings. Supported by the company Cannvalate and a foundation; the product was supplied by Brains Bioceuticals (according to the second publication, funding also came from Brains Bioceuticals) Side effects: No details in this publication; according to the authors, all side effects were mild and temporary. According to the second publication of the same trial (Narayan 2025), dry mouth was reported 25 times in 4 people in the CBD group and 6 times in 3 people with placebo (p = 0.003); 1 person in the CBD group stopped because of persistent restlessness | PMID 38174873, doi:10.5664/jcsm.10998, Daytime cognitive function and mood publication of the same trial: Narayan 2025, PMID 39153080, its findings are in this row’s outcome and side effect fields), ANZCTR ACTRN12620000070932 (prospectively registered) |
| Wang 2025 Double-blind, crossover RCT, phase 2 | 125 randomized; 62 completed; 56 analyzed Insomnia | CBD + 8 terpenes (1 mg each), THC-free | 300 mg CBD None (fixed dose; at least 4 nights a week) | ≥4 days a week, 4 weeks | Percentage of deep+REM sleep measured at the wrist +1.3% (marginal); total sleep time, resting heart rate and heart rate variability did not change; 63 of 125 people left before starting the drug, 6 more were removed after unblinding on grounds of protocol deviation, and the analysis was done in 56 people. Funded by the company Defined Research; 6 of 8 authors hold shares in the company, and 2 are unpaid advisers with stock options Side effects: No side effects reported | PMID 39167421, doi:10.5664/jcsm.11324, NCT05233761, results in the registry) |
| Kisiolek 2023 Randomized, placebo-controlled study | 28 (14/14) Healthy young adults (mean age 26) | Hemp-derived purified CBD gel capsule (50 mg); placebo MCT oil | 50 mg/day, 1–1.5 hours before bed | 8 weeks | On the overall sleep questionnaire (LSEQ) score, only an effect of time (it rose in both groups; 14.3% with placebo), no group × time interaction; a before–after increase in the CBD group (27.8%, a post hoc comparison). On the 'sleep quality' subscale, a group × time interaction in favor of CBD (p=0.002). Sleep time measured at the wrist, mental health measures and weight did not change Side effects: Not reported (no side effect data in the full text either) | PMID 37836465, doi:10.3390/nu15194173 |
| Saleska 2024 Double-blind RCT, 6 arms, remote; no placebo arm | 1793 Adults with symptoms of sleep disturbance | CBD isolate; CBD+CBN(±CBC); melatonin(±CBD+CBN) capsules | 15 mg CBD; 15 mg CBN; 5 mg CBC; 5 mg melatonin None | 4 weeks | Within-group improvement in all arms; no difference between CBD isolate and the CBN/CBC formulas and melatonin (no placebo arm). 4 of 8 authors are from the company Radicle Science (PubMed affiliation data); funding source not in the abstract Side effects: 12% side effects, none serious | PMID 37162192, doi:10.1080/27697061.2023.2203221 |
| Shannon 2019 Retrospective case series | 72 (25 with a primary sleep complaint) Psychiatric clinic patients | CBD capsule (supplied by CV Sciences; content and THC ratio not reported) | 25 mg/day in most; 50–75 mg/day in a few patients; 175 mg/day in 1 patient No standard schedule; according to physician preference | Monthly follow-up, up to 3 months | Sleep score improved in 66.7% at month 1, fluctuated over time (no control) Side effects: 3 patients could not tolerate it: 2 stopped in the first week because of tiredness; in 1 patient with a developmental disorder, CBD was stopped because of an increase in inappropriate sexual behavior. Mild sedation at first in 3 patients | PMID 30624194, doi:10.7812/TPP/18-041 |
| Walsh 2021 Double-blind, crossover RCT | 24 randomized / 23 completed Chronic insomnia | ZTL-101 sublingual cannabis extract: 20 mg/mL THC + 2 mg/mL CBN + 1 mg/mL CBD + terpenes (THC-dominant) | 0.5 mL 1 hour before bed (10 mg THC + 1 mg CBN + 0.5 mg CBD); could be raised to 1.0 mL (20 + 2 + 1 mg) from night 4 The dose could be doubled from night 4; on night 14, 12 of 23 people were on the double dose | 2 weeks/arm, 1-week washout | ISI −5.07; subjective total sleep +64.6 min; actigraphic WASO −10.2 min; no difference in sleep time or stages on polysomnography; all participants guessed they were receiving the active drug (blinding broken). Funded by the product company Zelira Therapeutics (according to the publication, design and analysis were in the hands of the investigators) Side effects: 36 mild side effects in the active period (17 people), 4 with placebo; dry mouth 33%, dizziness 25%; 1 auditory and 1 visual hallucination; no serious side effects | PMID 34115851, doi:10.1093/sleep/zsab149 |
| Ried 2023 Double-blind, crossover RCT | 29 Self-reported clinical insomnia | Entoura-10:15 oil (10 mg/mL THC + 15 mg/mL CBD) | 0.2–1.5 mL/day (calculated from the concentration in the publication: ~2–15 mg THC, ~3–22.5 mg CBD) 0.2 → 1.5 mL/day | 2 weeks/arm, 1-week washout | ISI and sleep quality improved; broken blinding was reported in phase 2 Side effects: 'Generally well tolerated' | PMID 36539991, doi:10.1111/jsr.13793 |
| So-Ngern 2025 Placebo-controlled RCT | 27 (26 analyzed) Patients with systemic sclerosis (scleroderma) with sleep problems (Thailand) | THC + CBD oil (2.7 mg THC + 2.5 mg CBD per mL), sublingual | Week 1, 1 drop × 2 (0.73 mg THC + 0.81 mg CBD), then 2 drops × 2 (2.92 mg THC + 3.24 mg CBD a day) Dose doubled after 1 week | 4 weeks | Improvement in sleep quality score (PSQI) greater than placebo but not significant (p=0.09) Side effects: 1 patient hospitalized for low sodium and sleepiness (withdrawn from the study); non-serious side effects 10 vs 7 | PMID 40430155, doi:10.3390/life15050727 |
| Suraev 2026 Crossover pilot RCT, HD-EEG | 20 DSM-5 insomnia | THC/CBD oral | 10 mg THC + 200 mg CBD single dose None | Single night | On the primary measures, total sleep −24.5 min (p = 0.05), time awake at night (WASO) no different from placebo (+10.7 min); REM −33.9 min; REM latency +65.6 min; subjective sleep quality did not change Side effects: Small increase in subjective sleepiness the next day (+0.42 points; p = 0.02), no difference in measured alertness; in the next-day publication of the same trial, a small drop on the Stroop task and an increase in feeling of sedation at hour 10 (Suraev 2024) | PMID 40631525, doi:10.1111/jsr.70124, ANZCTR ACTRN12619000714189 (prospectively registered). Next-day functioning publication of the same trial (secondary outcomes): Suraev 2024, PMID 38758300, no impairment compared with placebo on 27 of 28 cognitive and psychomotor tests or in a driving simulation, a small drop in accuracy on the easy Stroop task (−1.4%), a small increase in feeling of 'sedation' at hour 10, no difference in alertness and sleepiness scores |
| Hausenblas 2025 Double-blind, crossover pilot RCT | 20 Subthreshold insomnia | Softgel: 3 mg THC + 6 mg CBN + 10 mg CBD + 90 mg terpenes | 1 softgel at night (3 mg THC + 6 mg CBN + 10 mg CBD + 90 mg terpenes), 1 hour before bed None | 10 days/arm, 2-week washout | Compared with placebo, no difference in insomnia severity (ISI; p = 0.70) or overall PSQI score (p = 0.32). There is a borderline difference on the PSQI sleep quality subscore (p = 0.05); the borderline difference on the sleep efficiency subscore (p = 0.05) comes not from improvement during the product period but from worsening during the placebo period; the difference on the sleep medication use subscore favors placebo (p = 0.03). The abstract reports superiority over placebo on the ISI, but the comparison table in the full text does not show this. The product’s company, Sanna Science, partly funded the study Side effects: No side effects reported | PMID 39980821, doi:10.1002/hsr2.70481, ISRCTN 15022302 |
| Bonn-Miller 2024 Double-blind RCT, 5 arms | 301 enrolled (registration); 293 analyzed (mITT) 'Poor' sleep quality, ages 18–55 | CBN ± CBD | 20 mg CBN; +10/20/100 mg CBD None | 7 nights | On the primary measure (sleep quality), 20 mg of CBN was not significantly different from placebo (OR 2.26; 95% CI 0.93–5.52; p = 0.082); among the secondary measures, the number of night awakenings (p = 0.025) and overall sleep disturbance (p = 0.023) decreased; adding CBD added no benefit; falling asleep, WASO and daytime tiredness did not differ. Funded by Canopy Growth; 8 of 9 authors are employees of Canopy Growth and 1 of Wana Brands Side effects: No difference in daytime tiredness | PMID 37796540, doi:10.1037/pha0000682, NCT05839964, after the study ended in December 2022, the primary measure in the registration is the same as in the publication: sleep quality, no results in the registry) |
| Kolobaric 2024 Double-blind RCT, 5 arms | 1,020 randomized (CBN 25 mg 206, 50 mg 205, 100 mg 203; melatonin 4 mg 202; placebo 204) Adults wanting better sleep (remote, USA; no sleep disorder diagnosis required) | TruCBN (hemp-derived CBN); comparison with melatonin | 25, 50, 100 mg CBN; 4 mg melatonin None | 4 weeks (+1 week of product-free follow-up) | On the primary measure (PROMIS sleep disturbance), all CBN doses and melatonin gave slightly more improvement over the weeks than placebo (interaction coefficients −0.54 to −0.60; p = 0.018–0.030; the authors describe the difference for 25 and 100 mg as 'borderline'); no difference between CBN and melatonin; among the exploratory measures, stress decreased slightly more than with placebo only at 100 mg, and there was no difference from placebo in anxiety, pain and well-being. A company study run remotely with online surveys: funded by the product manufacturer FloraWorks, 6 of 8 authors are employees of Radicle Science, which ran the study Side effects: Side effect rate no different from placebo | PMID 39204082, doi:10.3390/ph17080977, NCT05511818, 679-person registration covering several products and a placebo arm, August 2022, the registration date is written in two different ways in the publication) |
| Lavender 2026 Double-blind, 3-arm crossover RCT, polysomnography | 20 DSM-5/ICSD-3 insomnia | CBN oral | 30 mg or 300 mg single dose None | Single night/arm, 2-week washout | The primary outcome (WASO) did not change; at 300 mg, time to fall asleep got shorter and subjective quality rose (secondary) Side effects: 247 mild-moderate side effects (total across all arms) | PMID 41698831, doi:10.1111/jsr.70284 |
| Chagas 2014 (RBD) Case series | 4 Parkinson’s + REM sleep behavior disorder | CBD | 75 mg/day (3 patients), 300 mg/day (1 patient) (according to review tables) not reported | 6 weeks (according to a review table) | Rapid and marked reduction in RBD events (no control). The conflict-of-interest statement could not be read (the publisher’s page blocks automated access); of the 12 authors, Zuardi, Hallak and Crippa state in other publications that they are inventors on a patent for a CBD derivative (the international application was published in 2014) Side effects: No side effects | PMID 24845114, doi:10.1111/jcpt.12179 |
| de Almeida 2021 (RBD) Double-blind RCT, phase 2/3 | 33 Parkinson’s + REM sleep behavior disorder | CBD capsule (add-on treatment) | 75–300 mg/day 75 → 300 mg (schedule not reported) | 14 weeks | Primary outcomes (frequency of RBD nights, CGI) not different from placebo; with 300 mg, a temporary increase in sleep satisfaction at weeks 4–8 (secondary). In a post hoc analysis of 18 patients who also had restless legs, restless legs severity also did not differ from placebo (de Almeida 2023). The conflict-of-interest statement could not be read (full text closed); of the 9 authors, Zuardi, Crippa and Hallak state in other publications that they are inventors on a patent for a CBD derivative and that their university has an agreement with a drug company for synthetic CBD Side effects: Not reported (in this abstract) | PMID 33754375, doi:10.1002/mds.28577, Exploratory restless legs syndrome analysis of the same trial: de Almeida 2023, PMID 35749710, no difference from placebo in symptom severity (IRLS) on primary and secondary outcomes, a post hoc analysis. Also a row in the Parkinson’s topic |
| AminiLari 2022 Systematic review and meta-analysis (39 RCTs) | 5100 33 in chronic pain/cancer | Oral cannabinoids (38 studies; most containing THC: THC+CBD mouth spray, dronabinol, THC and cannabis extracts; according to the trial list in the references, nabilone and CBDV studies are also included) and inhaled cannabis in 1 study | Various Various | Median 35 days | Small improvement in sleep quality in chronic pain (moderate certainty) Side effects: Dizziness (RD 29%, ≥3 months), drowsiness, dry mouth, tiredness, nausea | PMID 34546363, doi:10.1093/sleep/zsab234 |
| da Silva 2025 Systematic review and meta-analysis | 6 RCTs, 1077 people (total; the number of people in the CBD-only subanalysis is not in the abstract) People with and without insomnia | Cannabinoids | CBD-only treatments did not significantly improve sleep quality (SMD 0.13; 95% CI −0.38 to 0.65); the significant effect came from non-CBD/THC-containing formulas (SMD 0.82) | PMID 40929927, doi:10.1016/j.smrv.2025.102156 | ||
| Varela 2026 (Cochrane) Cochrane systematic review and meta-analysis (9 RCTs; 8 compared with placebo, 1 with amitriptyline) | 537 Adults with insomnia (ages 18–76; 73% women) | Medical cannabis (magistral preparations in 7 studies, approved (licensed) medicines in 2 studies: one plant-derived, one synthetic) | Variable | Compared with placebo, little or no meaningful contribution to sleep quality/satisfaction (SMD −0.49; 95% CI −1.06 to 0.08), total sleep (MD 7.68 min; −23.04 to 38.39) and daytime functioning (SMD −0.34; −0.83 to 0.16); evidence of very low certainty Side effects: Side effects may increase (OR 11.25; 4.46–28.35; 3 studies, 98 people; low certainty) | PMID 42863850, doi:10.1002/14651858.CD016216.pub2 | |
| Velzeboer 2025 Systematic review and meta-analysis (18 studies, 9 in the meta-analysis) | Studies in which sleep was measured by polysomnography | Cannabis and cannabinoids | Variable | Cannabis did not consistently change sleep time, falling asleep, wakefulness, efficiency or sleep stages; the drop in REM comes mostly from older, small studies with high THC doses; in newer studies it is mixed or absent. Stopping use consistently disrupted sleep | PMID 40967124, doi:10.1016/j.smrv.2025.102164 | |
| Wilson 2026 Systematic review and meta-analysis (54 RCTs in mental health and substance use disorders) | 2,477 (total; the number of people in the insomnia analysis is not in the abstract) People with insomnia (the meta-analysis’s insomnia analysis) | Cannabinoids (all types) | Variable | In insomnia, sleep time measured with an electronic device (SMD 0.54; 95% CI 0.14–0.95) and sleep time in sleep diaries (SMD 0.55; 0.01–1.09) increased with cannabinoids of all types compared with placebo; certainty of evidence low for most outcomes, high risk of bias in 44% of studies | PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, A correction was published in the journal: Lancet Psychiatry 2026, PMID 42302809, online June 16, 2026), it corrects the axis of a figure and the study counts in the table, and the results did not change | |
| Carlini 1981 Placebo- and active drug (nitrazepam)-controlled crossover study (double blinding and randomization not stated in the abstract; one review reports it as a 'crossover trial'); the same publication also summarizes studies in healthy volunteers and in epilepsy | 15 Volunteers with insomnia (Brazil) | Pure CBD, oral; comparison with placebo and 5 mg nitrazepam (a sleep medicine) | 40, 80 or 160 mg single dose None | Single dose (at night); how many nights it lasted is not in the abstract | Those taking 160 mg of CBD reported sleeping significantly longer than with placebo; at all three doses, dream recall was lower than with placebo. According to a review, there was no difference between CBD, nitrazepam and placebo in falling asleep. Measurements are based on people’s own reports; detailed numbers and statistics are not in the abstract. The publication is a report summarizing the same lab’s studies since 1972; an old 1981 study of 15 people whose methods cannot be assessed from the abstract Side effects: No separate information for the insomnia arm in the abstract; in the healthy volunteer studies in the same publication (10–600 mg), no signs of toxicity or intoxication were seen, and some volunteers complained of sleepiness | PMID 7028792, doi:10.1002/j.1552-4604.1981.tb02622.x |
| Nicholson 2004 Double-blind, placebo-controlled, 4-period crossover study (sleep lab) | 8 (4 women, 4 men) Healthy young adults (ages 21–34; United Kingdom) | Cannabis extracts sprayed into the mouth: THC alone or THC with an equal amount of CBD | At 22.00 at night over 30 minutes: placebo, 15 mg THC, 5 mg THC + 5 mg CBD or 15 mg THC + 15 mg CBD None | 4 nights (a single dose each) | 15 mg of THC did not change night sleep (EEG). When THC and CBD were given together, deep sleep (stage 3) decreased; with the high-dose combination, wakefulness during the night increased. The next morning (about 10 hours after the dose), those who took 15 mg of THC had weaker memory, fell asleep faster on a morning sleep-onset test and reported feeling sleepier; according to the authors, 15 mg of CBD showed a wakefulness-promoting effect and partly offset THC’s lingering next-day sleepiness. A very small study; funding and conflict-of-interest statements not in the abstract Side effects: Next-morning sleepiness, weaker memory and mood changes with THC | PMID 15118485, doi:10.1097/01.jcp.0000125688.05091.8f |
| Ware 2010 Double-blind, active drug (amitriptyline)-controlled, randomized crossover equivalence study | 31 enrolled; 29 completed (26 women) Fibromyalgia patients with chronic insomnia (Canada; mean age 49.5) | Nabilone (synthetic cannabinoid similar to THC) and amitriptyline, oral, at bedtime | Nabilone 0.5–1.0 mg, amitriptyline 10–20 mg; before bed Started at 0.5 mg and raised to 1 mg if needed | 2 weeks for each drug, with a 2-week drug-free period in between | On the primary measure, sleep improved with both drugs; nabilone was 3.2 points better than amitriptyline on the Insomnia Severity Index (ISI) (95% CI 1.2–5.3); borderline superior for feeling rested on waking (0.5; 0.0–1.0), no different for wakefulness (0.3; −0.2 to 0.8). There was no difference in pain, mood and quality of life. No placebo group, short duration; the only active-comparator study in the 2026 Cochrane review Side effects: More common with nabilone; most often dizziness, nausea and dry mouth; mostly mild–moderate | PMID 20007734, doi:10.1213/ANE.0b013e3181c76f70, NCT00381199, also a row in the fibromyalgia topic |
| Gilman 2022 Pragmatic RCT (getting a medical cannabis card right away or after 12 weeks; 2:1 randomization; participants were not blinded, only assessors were blinded) | 269 randomized; 186 analyzed (105 immediate, 81 waiting; in the immediate group only those who got the card and came to at least one follow-up: 53 of the 173 people assigned to this group did not get a card); the insomnia analysis is in the 42 people who applied for insomnia (22 immediate, 20 waiting) Adults ages 18–65 seeking medical cannabis for pain, insomnia, or anxiety or depression symptoms; daily cannabis users and people with cannabis use disorder were not included (USA, Boston) | Cannabis products chosen by the participant at a dispensary (THC and/or CBD; product, dose and frequency free) | Participant’s choice (product, dose and frequency free) Participant’s choice | 12 weeks | In those who applied for insomnia, the Athens Insomnia Scale (0–24, higher score worse) was 12.4 and 12.2 at the start; at week 12, 7.6 in those who got the card right away and 11.2 in those who waited; mean difference over the 12-week period −2.90 points (95% CI −4.31 to −1.51; p < 0.001). Participants knew their group and the measure was only self-rated; those who did not get a card were not included in the analysis; because product and dose are unknown, it cannot be said which cannabinoid was effective. In the same study there was no difference in pain, anxiety and depression; symptoms of cannabis use disorder rose in those who got a card, most in those who applied for anxiety or depression. According to the authors, development of use disorder was rare in those who applied for insomnia (number not in the text). Supported by the US National Institute on Drug Abuse (NIDA) Side effects: Across the whole sample, cannabis use disorder at 12 weeks 17.1% in those who got the card right away, 8.6% in those who waited (adjusted OR 2.88; 95% CI 1.17–7.07) | PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36638745, in card holders, reported sleep quality was better on days cannabis was used, and frequency of use rose). Also a row in the pain, depression and substance use topics |
| Kolobaric 2023 Double-blind, placebo-controlled, parallel 3-group, remote (online) RCT | 620 randomized (206 / 207 / 207); analysis with available data (about 26% of participants never filled in a follow-up survey) Self-reported healthy adults seeking better sleep (76% of participants complained most of sleep disturbance; no diagnostic screening was done; USA, October–December 2022) | Softgel supplements: 'Sleep A' (0.35 mg THC; 150 mg GABA, 75 mg each of hops and valerian oil), 'Sleep B' (0.85 mg THC; 125 mg GABA, 20 mg each of hops and valerian oil); both with the same amounts of CBD, CBN and L-theanine (amounts not in the publication) | 1 capsule 30 min before bed; could be increased to at most 4 capsules a day if needed At least 5 days of waiting before increasing; at most 4 capsules a day; the number of capsules used did not differ between groups | 4 weeks (+1 week of product-free follow-up) | On the primary measure (PROMIS sleep disturbance), sleep disturbance decreased more over the weeks with Sleep A than with placebo (week × group interaction β −0.639; p = 0.0027); with Sleep B, which contained more THC, there was no difference from placebo on any measure. The planned second primary measure (proportion achieving meaningful improvement) was not reported in the results. Because it is a multi-ingredient product, it cannot be known whether the effect came from THC or from the plant ingredients; data were collected with online surveys. Funded by the product brand MDbio; 5 of 8 authors are employees of Radicle Science, the company that ran the study Side effects: Side effects slightly more common in the active groups (p = 0.059); mostly lightheadedness and sleepiness, mild; no serious side effects or events requiring health care | PMID 37686820, doi:10.3390/nu15173788, NCT05511818, according to the publication, not this study’s own registration, Kolobaric 2024 in the table also cites the same template) |
| Peball 2022 Post hoc sleep analysis of a double-blind, placebo-controlled, enriched randomized withdrawal trial (NMS-Nab) | Of the 38 randomized patients in the trial, the 31 with marked sleep problems at the start (17 nabilone / 14 placebo) Parkinson’s patients with troublesome non-motor symptoms and marked sleep problems at the start (Austria); sleep problems were not an inclusion criterion for the trial | Nabilone (synthetic cannabinoid similar to THC, oral capsule) | Mean 0.9 mg/day at randomization (median 1 mg; 0.25–1.75 mg) In the open-label period, started at 0.25 mg/day and increased according to response; only responders were randomized | Open-label dose finding + 4-week double-blind period | With open-label nabilone, 77% of patients no longer had marked sleep problems (uncontrolled). In the double-blind period, sleep problems got worse in those switched to placebo and did not get worse in those who stayed on nabilone: difference on the nighttime sleep problems item 1.88 points (95% CI 1.04–2.73; p < 0.001), on the sleep/fatigue domain 8.57 (2.24–14.91; p = 0.011), on the insomnia question 5.00 (1.92–8.09; p = 0.004); no difference in daytime sleepiness. A post hoc subgroup analysis, and only drug responders were randomized; so the effect may look larger than it would be for all patients. The manufacturer AOP Orphan supplied the drug and placebo and covered visit and monitoring costs; 1 of 10 authors received fees outside the study from this company Side effects: No separate side effect data in this publication (in the main trial, side effects in the double-blind period 32% with nabilone, 42% with placebo; Peball 2020 row in the Parkinson’s topic) | PMID 35937495, doi:10.1002/mdc3.13471, PMID 32757413, row in the Parkinson’s topic), NCT03769896, EudraCT 2017-000192-86, PMID 38491070, uncontrolled, 22 patients) |
| Walczyńska-Dragon 2025 Sleep and migraine results of a double-blind, placebo-controlled, 3-group RCT (secondary publication of the same trial; the main publication examined pain, muscle tension and teeth clenching); according to this publication, the placebo gel was clear and the CBD gels slightly opaque, and according to the main publication, the CBD gels were slightly bitter (blinding may have been compromised; according to the authors, participants were not told about these differences and no one reported noticing their group) | 60 analyzed (20 / 20 / 20); according to the main publication, 66 randomized, completers only analyzed Young adults with sleep bruxism (clenching/grinding teeth during sleep) and chewing muscle pain (mean age 24; Poland) | CBD gel applied inside the mouth to the chewing muscle (prepared with 100% CBD isolate, 5% and 10%); comparison with placebo gel | Every night before bed, inside the mouth onto the chewing muscles on both sides; according to this publication, 25 mg of CBD in the 5% gel and 50 mg in the 10% gel per 0.5 mL single-dose container; the main publication, however, states 20 mg/day for the 5% gel and 40 mg/day for the 10% gel (the two publications do not match) None | 30 days | Sleep quality (PSQI; 0–21, higher score worse) improved more over 30 days with both CBD gels than with placebo (5%: p = 0.002; 10%: p < 0.001; no correction for multiple comparisons); the median score fell from 12 to 7 with the 10% gel and from 12 to 8 with the 5% gel, and stayed at 9 in the placebo group; no difference between the two doses; the impact of migraine on daily life also decreased. At the start, the CBD groups had worse sleep scores than the placebo group (12 vs 9). The sleep measure is not in the study’s ClinicalTrials.gov registration or in the methods of the main publication; the two publications describe the randomization method and the dose differently. Single-center, small and young sample; teeth clenching during sleep is a sleep movement disorder, but participants were not selected for insomnia; in the main publication there was no difference between groups in teeth-clenching severity. This publication has no funding section (the main publication was university-funded); the authors reported no conflicts of interest Side effects: No gel-related side effects were reported in any group; no stopping due to side effects | PMID 40732351, doi:10.3390/ph18071064, PMID 38592260, row in the topical CBD topic), NCT05562635, no sleep measure) |
| Emerson 2026 Triple-blind, placebo-controlled, remote (online) RCT | 63 randomized (33 CBG / 30 placebo); 55 people completed the study; 35 people in the per-protocol analysis (18 / 17). The planned 50 people per arm were not reached Veterans reporting sleep problems (USA, California; mean age 44, 78% men; 86% regularly used cannabis and were allowed to continue during the study; probable PTSD in more than 40%) | CBG (cannabigerol)-dominant tablet; matching placebo | 25 mg/day for 2 weeks, then 50 mg/day for 2 weeks (at least 3 hours before bed) Dose doubled after 2 weeks | 2-week placebo run-in + 4 weeks of treatment | On the primary measure (MOS sleep problems index), both groups improved; the difference favored placebo and was not significant (4.4 points; 95% CI −4.1 to 13.0; p = 0.3; per-protocol 3.8; −4.8 to 12.0). Scores had also improved during the 2-week placebo run-in before the drug started. No difference in quality of life or PTSD symptoms either; sleep measured at the wrist did not change. Most participants were using other cannabis products at the same time, and the trial did not reach its planned size. Funded by the product manufacturer Metta Medical (LEVEL); all 5 of 5 authors have ties to the company: 1 is a company employee and shareholder, 1 is an employee of the firm the company hired to run the study, and 3 are consultants paid by this firm or the company Side effects: 5 mild side effects possibly related to CBG (headache, fatigue, stomach upset, nausea, oversleeping; each in 1 person); 2 people left the study; no serious side effects | PMID 41574318, doi:10.1159/000549902, NCT05088018 |
| Gournay 2026 Sleep results of a double-blind, placebo-controlled, 3-group RCT (the anxiety results of the same trial are in a separate publication) | 63 Adults with high levels of worry (mean age 29; USA, Arkansas) | Pure CBD, oral; matching placebo | 50 or 300 mg/day None | 2 weeks, daily | 300 mg of CBD reduced sleep problems significantly more than 50 mg (B = −0.39; p < 0.05), but the difference from placebo was not significant (B = −0.32; p = 0.10); effect sizes very small (d = 0.07–0.08). No sleepiness or cognitive impairment was seen. The authors state that no strong conclusion can be drawn. Participants were not selected for sleep problems Side effects: No sleepiness or cognitive impairment; no other side effect information in the abstract | PMID 41678223, doi:10.1037/pha0000832, PMID 37552290, row in the anxiety topic), this publication is also in the anxiety table under the name 'Gournay 2026 (sleep results)' |
| Kamoltham 2026 Phase 2, double-blind, double-dummy, active drug (lorazepam)-controlled, randomized equivalence (non-inferiority) study | 100 randomized (50 / 50); 82 completed and were analyzed (41 / 41; completers only) Adults ages 25–70 with insomnia symptoms for at least 1 month and PSQI > 5 (Thailand, Chanthaburi) | Traditional Thai 'Anti-Pom-Leung Fever' (Prasa Kuncha) blend: 8 plants, half by weight roasted cannabis leaf; measured at 6.6 mg THC, 5.8 mg CBN and 4.1 mg THCV per gram, CBD not detected. Comparison with lorazepam 0.5 mg | 4 of the 500 mg capsules before breakfast and 4 at bedtime (4 g of the blend a day). The daily amount of cannabinoids is not stated in the publication; multiplying the per-gram content in the table (6.6 mg THC, 5.8 mg CBN, 4.1 mg THCV) by the daily 4 g gives about 27 mg THC, 23 mg CBN and 16 mg THCV (a calculation made on this page, not in the publication; not a personal recommendation) None | 4 weeks | At week 4, PSQI was 3.44 with the blend and 4.78 with lorazepam; difference −1.34 (95% CI −2.99 to 0.31); based on a prespecified 2.1-point margin, it was concluded not to be worse than lorazepam. In both groups, PSQI fell clearly from 12–13; because there was no placebo group, how much of the improvement came from the drug cannot be known. Only completers were analyzed, measurement by questionnaire only; registered after the study ended (study August 2023–February 2024, registration July 2024). Supported by the Thai Traditional Medicine Knowledge Fund; the authors reported no conflicts of interest Side effects: Mild side effects that went away on their own, no difference between groups: dizziness 4 people (9.8%) vs 1, sleepiness 1 vs 0, palpitations 1 vs 0, stomach complaints 1 vs 1, fever 0 vs 1; small ECG changes at the end of treatment 6 vs 8 (5 vs 8 in the text; also 5 vs 8 at the start; not significant); no difference in liver, kidney and blood values | PMID 41736083, doi:10.1186/s42238-026-00415-x, Thai Clinical Trials Registry TCTR20240718004 (after the study ended) |
| Pakdee 2026 Open-label, randomized, 3-group parallel study (only assessors blinded; no placebo) | 60 (20 / 20 / 20) Adults ages 40–70 with chronic insomnia by DSM-5, PSQI ≥ 5; people taking sleep medicines or antidepressants were not included (Thailand, Kamphaeng Phet) | 'Deja formula' cannabis oil (from the hospital’s traditional medicine unit; THC and CBD content not in the publication); comparison with the Suk-Sai-Yat herbal blend (which also contains cannabis) and lorazepam 1 mg | 1 drop (0.05 mL) before bed; in the publication the route is written as 'subcutaneous', without explanation None | 4 weeks | PSQI fell in all three groups (cannabis oil 13.6 → 5.1; herbal blend 12.3 → 6.6; lorazepam 14.4 → 5.8; within-group p < 0.01); no difference between groups at the end of treatment (p = 0.27). The comparison was not designed to show equivalence or superiority; the authors also write in their reply letter that they do not interpret the finding as equivalence. Quality of life rose more in the cannabis and herbal blend groups than with lorazepam, but the groups also differed at the start. No placebo, participants knew their group, the study was not registered, and the product content is unknown; the final cannabis oil value in the abstract (3.68) does not match the table in the text (5.10) (3.68 is the same number as the baseline standard deviation in the table). No funding; the authors reported no conflicts of interest Side effects: In the cannabis oil group, headache, dizziness and nausea in 1 person (5%); with the herbal blend, palpitations and muscle pain in 2 people; in the lorazepam group, no side effects in the table, mild daytime sleepiness in some people in the text; no serious side effects | PMID 41623556, doi:10.1016/j.sleepx.2026.100173, PMID 41756111, PMC12933466): they acknowledge as limitations that no sleep apnea screening was done and that the analysis relied on within-group before–after change |
| Carley 2018 (PACE) Phase 2, multicenter, fully blinded, placebo-controlled, parallel 3-group RCT | 73 randomized and analyzed (25 placebo, 21 dronabinol 2.5 mg, 27 dronabinol 10 mg); 56 people completed the protocol Adults ages 21–65 with moderate or severe obstructive sleep apnea (15–50 breathing pauses or reductions per hour) and daytime sleepiness (USA, Chicago; mean body mass index 33) | Dronabinol (synthetic THC), oral capsule, 1 hour before bed | 2.5 mg or 10 mg/day In the 10 mg group, to follow the drug label, it was started at 2.5 mg/day in the first week and 5 mg/day in the second week, then raised to 10 mg/day; fixed dose in the placebo and 2.5 mg groups | 6 weeks (preceded by a 5–10-day placebo run-in) | On the primary measure (breathing pauses/reductions per hour, AHI), compared with placebo it was 10.7 ± 4.4 (p = 0.02) events/hour lower with dronabinol 2.5 mg and 12.9 ± 4.3 (p = 0.003) lower with 10 mg; the two doses did not differ from each other. Part of the difference comes from AHI rising in the placebo group (after adjustment for age, race, ethnicity and baseline value, this rise was not significant); according to the results on ClinicalTrials.gov, among those who completed the study AHI fell by 1.7 and 5.2 per hour with dronabinol and rose by 8.0 with placebo. With 10 mg, daytime sleepiness (Epworth) fell 2.3 points more than with placebo (p = 0.05). The maintenance of wakefulness test, sleep structure and night oxygen levels did not change. A short study, only initial findings were published, and the precalculated 37 people per group were not reached (21–27 people). NIH-supported; 1 of 10 authors (the lead author) is the inventor on patents for treating sleep-disordered breathing with cannabinoids and a shareholder in RespireRx, the company that licenses these patents Side effects: According to the publication, 88% of participants reported at least one side effect and the rate did not differ between groups; most often sleepiness, headache, nausea/vomiting, dizziness. The results on ClinicalTrials.gov differ, however: sleepiness was reported in 17 of 27 people in the 10 mg group and in no one in the placebo and 2.5 mg groups; headache 13 vs 4, nausea 9 vs 1 (10 mg vs placebo). 7 people left because of side effects (some during the placebo run-in); those thought possibly related to the drug included dizziness and changes in vision, a spinning sensation (vertigo), a heart rhythm disturbance on ECG, headache and vomiting. 1 person stayed one night in the hospital because of vomiting and diarrhea | PMID 29121334, doi:10.1093/sleep/zsx184, NCT01755091, PMID 29361189 |
| Walsh 2025 Double-blind, placebo-controlled, randomized crossover dose-finding study (single-blind placebo run-in) | 11 randomized; 9 analyzed (8 completed all doses) Patients with obstructive sleep apnea with at least 15 breathing pauses/reductions per hour (Australia; mean age 54) | Dronabinol + acetazolamide combination (IHL-42X), oral, 1 hour before bed | Low: 2.5 mg dronabinol + 125 mg acetazolamide; medium: 5 mg + 250 mg; high: 10 mg + 500 mg None (each dose in a separate period, in random order) | 7–8 nights for each dose and placebo, with at least 7 drug-free nights in between | According to the table in the full text, AHI fell from baseline by 19.4 ± 27.3 events/hour at the low dose, 17.8 ± 23.6 at the medium dose and 18.2 ± 24.8 at the high dose, and by 4.6 ± 21.5 with placebo (all p < 0.001 vs placebo; about a 35–40% reduction; the numbers in the abstract differ slightly). On the oxygen desaturation index, only the medium dose was better than placebo; the arousal index decreased; daytime sleepiness, mood and sleep structure did not change. 9 people and 1 week per dose; acetazolamide is itself a drug that reduces sleep apnea, and dronabinol’s contribution was not measured separately. Funded by the manufacturer Incannex; 2 of 12 authors are company employees and shareholders Side effects: 35 mild–moderate side effects possibly related to the drug (in 6 people): 16 at the medium dose, 10 at the high dose, 4 at the low dose, 5 with placebo; most often tingling in the fingers (4 of 9 people), constipation, nausea, diarrhea; no serious side effects or stopping due to side effects | PMID 39589391, doi:10.1093/sleep/zsae276, ANZCTR ACTRN12620000916943, PMID 40328187 |
| Cousens 1973 Experimental dose study (three dose levels); randomization, placebo control and number of participants not in the abstract (one review refers to it as an RCT) | Not reported (in the abstract) Physically healthy people with insomnia (men, according to PubMed indexing; country and number of participants not in the abstract) | (−)Δ9-THC, oral | Three dose levels; only 30 mg is mentioned in the abstract, the other doses are not Not reported (in the abstract) | Not reported (in the abstract) | THC significantly shortened the time to fall asleep; awakenings during the night did not change significantly (a trend toward fewer in the first half of the night). The authors wrote that because of a 'hangover' lasting into the next day at 30 mg, this dose should not be considered as a sleep medicine. An old study from 1973 whose methods cannot be assessed from the abstract Side effects: Distorted time perception and mood changes before falling asleep (at all doses; more frequent and severe as the dose increased); a 'hangover' or a feeling of lingering intoxication the next day, lasting longer depending on the dose | PMID 4776660, doi:10.1007/BF00437513 |
| Prasad 2013 Open-label, single-center dose-escalation study (no control group) | 17 enrolled; 15 people completed 21 days Patients with obstructive sleep apnea with at least 15 breathing pauses/reductions per hour; after stopping CPAP for 7 days (USA, Chicago) | Dronabinol (synthetic THC), oral, 30 min before bed | Increased once a week, 2.5 → 5 → 10 mg/day (if tolerated) Each dose for 7 days; if side effects occurred, the dose was kept the same | 3 weeks | On night 21, AHI fell by 14.1 ± 17.5 events/hour from baseline (p = 0.007 in the abstract, 0.003 in the text); sleep structure was not disrupted, oxygen measures did not improve; the sleepiness score decreased slightly (p = 0.05). No control group, duration 3 weeks. Done with a donation from the company Pier Pharmaceuticals; 1 of 3 authors had previously been on this company’s board of directors Side effects: Side effects in 76% of patients at 2.5 mg, 57% at 5 mg, 75% at 10 mg; most often sleepiness (50% at 10 mg), increased appetite at 2.5 mg (23%); 1 person was withdrawn for palpitations and 1 for a drop in oxygen; no serious side effects | PMID 23346060, doi:10.3389/fpsyt.2013.00001, PMID 24426820 |
| Messineo 2023 Open-label, two-center, 4-period dose-escalation study (no placebo; comparison with baseline and with atomoxetine alone) | 15 Patients with obstructive sleep apnea with 10–50 breathing pauses/reductions per hour, ages 25–65 (USA) | Atomoxetine (a drug that blocks noradrenaline reuptake) + dronabinol | Week 1 atomoxetine alone (40 → 80 mg); then weekly atomoxetine + dronabinol 40 + 2.5 mg, 80 + 5 mg, 80 + 10 mg Weekly dose increases | About 4 weeks (weekly dose increases) | No significant improvement from baseline on the primary measure (AHI with 80 mg atomoxetine + 10 mg dronabinol). On a secondary measure, at the 80 + 5 mg dose, AHI fell by 8.3 events/hour from baseline (95% CI 0.3–16.3) and oxygen burden decreased; at no dose was there a difference compared with the atomoxetine-only period; dronabinol was not tested alone. Because of side effects and a narrow treatment window, the authors advise against using this combination in sleep apnea for now. Open-label, no placebo. Funded by the company Apnimed, which took part in the design; all 3 of 3 authors have ties to the company (consulting or research funding) Side effects: According to the registry, side effects were also common in the first week on atomoxetine alone (9 of 15 people; most often insomnia); in the weeks when dronabinol was added, 7 of 14, 6 of 12 and 5 of 11 people reported side effects. Those seen with the combination include excessive suspiciousness (paranoia; 2 people), a state of detachment (1 person), suicidal thoughts (1 person, during the 80 mg atomoxetine + 5 mg dronabinol period), raised blood pressure, a racing heartbeat (tachycardia) and nausea; no serious side effects were reported. 5 of 15 people did not finish the study (1 in the atomoxetine-only week, 4 during the combination periods; one by the physician's decision) | PMID 36805833, doi:10.5664/jcsm.10528, NCT05101122 |
| Lillo Triguero 2026 Prospective, open-label exploratory study (no control group) | 18 (16 of them with multiple sclerosis) Patients with restless legs syndrome; 16 with multiple sclerosis, normal iron levels (Spain, Getafe) | THC + CBD (2.7 mg THC / 2.5 mg CBD; product name and form not in the abstract) | 2.7 mg THC / 2.5 mg CBD (how many times a day it was taken is not in the abstract); dose adjustment at week 4 if needed Increase at week 4 if needed (schedule not in the abstract) | 3 months (1-year follow-up) | Restless legs severity (IRLS) improved significantly at months 1 and 3 (p < 0.001); time awake at night measured by actigraphy decreased (p = 0.015), while time to fall asleep and sleep efficiency did not change; at 1 year, 67% of patients were continuing treatment and the improvement was holding. No control group, most patients had MS; a placebo effect cannot be ruled out. Supported by the IdiPAZ research institute; all 5 of 5 authors reported fees, travel support or research funding from drug or health companies (two from Almirall) Side effects: Not reported (in the abstract) | PMID 42387200, doi:10.1007/s00415-026-13975-y |
| Asim 2026 Systematic review and meta-analysis of RCTs (up to January 2025) | 10 RCTs, 2,134 people Adults with insomnia or poor sleep quality | Cannabinoids (types not specified separately in the abstract); comparison with placebo or melatonin | Variable | Compared with placebo or melatonin, insomnia severity (ISI; mean difference −3.73; 95% CI −5.04 to −2.42) and sleep quality (PSQI; −3.94; −5.47 to −2.40) improved with cannabinoids; total sleep got longer by 34 min (20–48), sleep efficiency rose by 4.3% (3.0–5.6), and time to fall asleep got shorter by 12 min (95% CI −22.6 to −1.4; p = 0.03). The authors see cannabinoids as a possible option. The Cochrane review published the same year (Varela 2026), however, found the certainty of evidence very low; the abstract of this review does not grade the certainty of the evidence, and very different products, doses and comparisons (including melatonin) were assessed together; the list of included studies could not be read Side effects: Side effects more common with cannabinoids (RR 3.96; 95% CI 1.75–9.00), mostly mild dizziness and dry mouth; no serious harm observed | PMID 42574897, doi:10.1016/j.sleep.2026.109193, PMID 42753382, contents could not be read) | |
| Drager 2023 (Brazilian Sleep Association) National clinical guideline (Brazilian Sleep Association; systematic literature searches, Oxford levels of evidence, expert voting) | Adults with chronic insomnia | Cannabis (Cannabis sativa), CBD and Δ9-THC | Cannabis, CBD and THC are not recommended for difficulty falling asleep and staying asleep (level of evidence 3 for all three; consensus 94–100%); they are also not recommended in pregnancy and breastfeeding. Rationale: studies lasted at most 8 weeks, there are no quality studies to guide dosing and safety; it is not known whether the improvement in sleep comes through anxiety or pain Side effects: The guideline’s summary: with CBD, sleepiness, stomach pain, diarrhea, raised liver enzymes; interactions with valproate and clobazam; with THC, sleepiness, euphoria, psychosis at high doses, misuse and withdrawal | PMID 38370879, doi:10.1055/s-0043-1776281 | ||
| Ramar 2018 (AASM) Position statement (American Academy of Sleep Medicine) | Adults with obstructive sleep apnea | Medical cannabis and its synthetic extracts (including dronabinol) | The AASM stated that medical cannabis or its synthetic extracts should not be used to treat sleep apnea because of unreliable delivery methods and insufficient evidence of efficacy, tolerability and safety; it asked that sleep apnea be removed from the lists of conditions in state medical cannabis programs. The 73-person placebo-controlled dronabinol study (Carley 2018) was also included in the assessment; according to the statement, the dronabinol studies are small 3–6-week studies, long-term effects are unknown, and the most effective treatment is positive airway pressure (CPAP); it recommends that patients discuss treatment options with a physician at a sleep center Side effects: It notes that side effects occurred in most patients in the dronabinol studies and that sleepiness was reported in 29–50% in the first study; it states that daytime sleepiness can lead to unwanted outcomes such as traffic accidents | PMID 29609727, doi:10.5664/jcsm.7070, PMID 30353820, PMID 30353823, 30353829 (contents not read) | ||
| Boylan 2024 Systematic review (no meta-analysis) | 9 studies (5 full texts, 4 conference abstracts) Adults with obstructive sleep apnea | Dronabinol in 7 experimental studies, cannabis in 2 observational studies | Variable | 8 of 9 studies reported a significant positive result, such as a reduction in the number of breathing pauses or an improvement in daytime sleepiness; treatment durations 1–6 weeks (median 3 weeks). 4 of the 9 studies are conference abstracts only; of the 5 full-text studies, 2 had low, 1 moderate and 2 high risk of bias. The authors stress that there are no long-term efficacy and safety data and that longer, adequately sized studies are needed; they note that the AASM does not recommend cannabinoids Side effects: Nervous system or digestive side effects in 70–80% of participants | PMID 39498540, doi:10.1002/phar.4622 | |
| Saha 2026 Scoping review (PRISMA-ScR; up to April 2025; no meta-analysis) | 7 studies Adults with restless legs syndrome | Cannabis and CBD (smoked cannabis, sublingual CBD, CBD capsules, cannabidiolic acid cream applied to the skin) | Variable | Of the 7 included studies, 2 are case series (6 and 12 patients; complete or near-complete resolution of symptoms was reported, mostly with smoked cannabis), 3 are surveys, 1 is an uncontrolled 10-person cream study, and 1 is an analysis done afterward of a controlled trial (de Almeida 2023; no difference between CBD and placebo). According to the authors, no clinical recommendation can be made without high-quality RCTs | PMID 42617004, doi:10.4103/aian.aian_1168_25, PMID 28655453, 6 patients), PMID 31820197, 12 patients), NCT06570941 | |
| Trenkwalder 2024 (German guideline) National guideline (German Sleep Society and German Neurological Society; abbreviated guideline) | Patients with restless legs syndrome | Cannabinoids (THC and CBD) | Because THC and CBD have not yet been studied in randomized controlled trials in restless legs syndrome, treatment with cannabinoids cannot be recommended and should not be used (as of November 2024, when the guideline was published) | PMID 39501372, doi:10.1186/s42466-024-00353-0, Cannabinoids are not addressed in the American Academy of Sleep Medicine’s 2025 restless legs guideline (Winkelman 2025, PMID 39324694 | ||
| Koye 2026 (UK Medical Cannabis Registry) Prospective observational cohort (patient registry; no control group) | 211 Patients whose primary reason for prescription was insomnia, who had not responded adequately to licensed medicines, and who were prescribed self-paid cannabis-based medicines at a private clinic (United Kingdom; mean age 42, 73% men); 60% were already using cannabis at the start, and only 40 people (19%) had never used it before | Prescription cannabis-based medicines: dried flower inhaled by vaporizing (41%), oil (30%) or both (29%) | At month 24, median THC 143 mg/day (interquartile range 110–248), CBD 13.75 mg/day (6–48); at the start, THC 20 mg/day By physician decision; the THC dose rose over time (median 20 → 143 mg/day); the authors consider the rising dose and the narrowing improvement over time a possible sign of tolerance | 24 months | Single-item sleep quality score (0–10) 2.46 at the start, 5.14 at month 24 (difference 2.68; 95% CI 2.23–3.14); better than baseline at all time points; anxiety and quality of life also improved. No control group; missing data were filled in statistically; participants were paying patients, most of whom had used cannabis before (expectation effect); no objective sleep measurement; the authors note that the improvement in the worst sleepers may partly be regression to the mean. The registry belongs to Curaleaf Clinic; 7 of 8 authors work at Curaleaf or are executives there Side effects: 17 of 211 people (8%) reported at least one side effect: most often insomnia (13; 5 of them severe), tiredness (12), dry mouth (10), sleepiness (9); none life-threatening; more common over age 60 (adjusted OR 19.1; 95% CI 1.5–536) | PMID 42935025, doi:10.1002/npr2.70180, PMID 38337193, 61 patients, PMID 41662070, 124 patients, 18 months) |
| Roepke 2026 Multicenter (Germany), double-blind, placebo-controlled, parallel-group RCT (phase 2) | 171 randomized (87 dronabinol, 84 placebo); efficacy analysis 169 (87/82); safety analysis 170 (87/83) Adults diagnosed with PTSD with recurring nightmares (mean age 37.9; 79.3% women; 46% were in psychotherapy and 62% were taking antidepressants during the same period); participants were selected for nightmares, not for insomnia | Dronabinol (synthetic THC; BX-1, oral), before bed; matching placebo | Started at 2.5 mg as 1 dose a day, up to 15 mg/day Per protocol, 2.5 mg for 4 days, then 2.5 mg increases on days 5, 8, 12, 15 and 19; the target was the dose at which nightmares disappeared (up to 15 mg) | 10 weeks (4 weeks of dose adjustment + 6 weeks at a fixed dose); follow-up at week 12 | On the primary measure (nightmare frequency and severity, CAPS-IV B2, 0–8 points), the drop at week 10 was −3.66 points with dronabinol and −2.17 with placebo; difference −1.50 (95% CI −2.28 to −0.71; p < 0.001; effect size d = 0.65); similar in sensitivity analyses. At least a halving of nightmares 57.9% vs 29%, complete disappearance 36.8% vs 14.5% (no correction for multiple comparisons). Week-10 difference in sleep quality (PSQI) −1.28 points, in PTSD-specific nighttime symptoms (PSQI-A) −2.22 points (both uncorrected additional analyses; p = 0.046 and p < 0.001). The difference in overall PTSD severity (CAPS-5) was not significant (p = 0.08). 80.8% of those taking dronabinol and 52.5% of those taking placebo correctly guessed their group (mostly based on the drug’s effects), and reports of improvement were strongly linked to this guess; this can make the result look better than it is. A single large study. Investigator-initiated; the manufacturer Bionorica provided an unrestricted grant and the study drug (according to the publication, it had no role in design or analysis; the 2023 protocol publication also names Canopy Growth as a funder); 1 of 20 authors (the lead author) had received personal fees from Bionorica before the contract Side effects: Any side effect 89.7% vs 77.1%; serious side effects in 7 (8.0%) people vs 0 (the investigators attributed none to the drug); stopping due to side effects 5.7% vs 7.2%; dizziness 23% vs 14.5%, increased appetite 16.1% vs 8.4%, diarrhea 11.5% vs 3.6%, dry mouth 9.2% vs 1.2% | PMID 42557458, doi:10.1038/s41591-026-04546-9, NCT04448808, October 28, 2026), PMID 37147642, also a row in the PTSD topic |
| Jetly 2015 Double-blind, placebo-controlled, randomized crossover pilot study | 10 (mITT) Canadian male soldiers diagnosed with PTSD whose trauma-related nightmares continued despite standard treatment | Nabilone (synthetic cannabinoid similar to THC, oral capsule) | Started at 0.5 mg and increased until nightmares were suppressed, up to 3.0 mg Increase to the effective dose or to the 3.0 mg ceiling | 2 × 7 weeks, with a 2-week washout in between | Reduction on the CAPS nightmare item −3.6 with nabilone, −1.0 with placebo (p = 0.03); clinical global impression of change (CGI-C) 1.9 vs 3.2 (p = 0.05); 5 of 10 people improved greatly with nabilone, 1 of 9 with placebo. A very small pilot study (10 people, male soldiers only) Side effects: Treatment-related side effects 50% with nabilone, 60% with placebo; no severe side effects or stopping due to side effects | PMID 25467221, doi:10.1016/j.psyneuen.2014.11.002, Health Canada registration, also a row in the PTSD topic |
| Morgenthaler 2018 (AASM) Position statement (American Academy of Sleep Medicine; literature search March 2009–August 2017 and expert opinion; a position statement instead of a guideline because the evidence is limited) | Adults with nightmare disorder and PTSD-related nightmares | Nabilone (synthetic cannabinoid similar to THC); for cannabis it says only 'there is not enough evidence to make a recommendation' | For PTSD-related nightmares, nabilone is among the options that 'may be used'; in the statement this is a weaker level than 'recommended', where the evidence or expert opinion is uncertain. The basis is only a 10-person RCT (Jetly 2015). It states that there is not enough evidence to make a recommendation for cannabis. The only 'recommended' treatment for nightmares is imagery rehearsal therapy (a psychotherapy method) Side effects: For Jetly 2015, the most common were reported to be dry mouth and headache | PMID 29852917, doi:10.5664/jcsm.7178, Also a row in the PTSD topic, PMID 32088375 |
Reported side effects
- Dry mouth (150 mg/night; Narayan 2024)
- With THC/CBD, a small increase in subjective sleepiness the next day and a feeling of sedation at hour 10 (Suraev 2026; next-day publication of the same trial Suraev 2024)
- CBD increased drowsiness in epilepsy studies (moderate certainty; Solmi 2023, PMID 37648266)
- In chronic pain, with cannabinoids (most containing THC): dizziness (RD 29%), drowsiness, dry mouth, tiredness, nausea (AminiLari 2022)
- Dronabinol in sleep apnea: sleepiness (at 10 mg, 17 of 27 people in the Carley 2018 registry record, 0 with placebo; 50% in Prasad 2013); in combination with acetazolamide, tingling in the fingers, constipation, nausea (Walsh 2025); in combination with atomoxetine, excessive suspiciousness (paranoia), a state of detachment and suicidal thoughts in one person; in this open-label study, side effects were also common in the first week on atomoxetine alone (9 of 15 people), and a third of patients did not finish the study (Messineo 2023, registry NCT05101122)
Monitoring done in studies
- With pure CBD, 150 mg at night did not impair daytime cognitive performance (Narayan 2024); with THC-containing products, next-day sedation should be monitored
- With THC-containing products, signs of cannabis use disorder should be monitored (Gilman 2022); in people with sleep apnea, cannabis products should not replace treatment, and follow-up with a sleep physician should continue (Ramar 2018)
Who should be careful
- Together with sleep medicines, benzodiazepines or sedatives: extra sedation and higher drug levels are possible; physician monitoring is required
- Driving: 13.75 mg of vaporized CBD-dominant cannabis did not impair driving, but clinically important impairment could not be fully ruled out; THC-containing products impaired it (Arkell 2020, PMID 33258890)
- Older adults: sleep studies were mostly in young/middle-aged people; pharmacokinetics, multiple medicines and interactions may differ (Draghmeh 2026, PMID 42855715)
- Some of the CBN and formula studies were run by companies that make the products
- Sleep apnea: dronabinol and cannabis products do not replace CPAP or the treatment recommended by a sleep physician; the AASM recommends against their use (Ramar 2018); dronabinol can cause sleepiness (at 10 mg, in half of patients in Prasad 2013 and in 17 of 27 people in the Carley 2018 registry record)
- Cannabis use disorder: in people who got a cannabis card for pain, insomnia, anxiety or depression, 17.1% vs 8.6% at 12 weeks; most in those who applied for anxiety or depression (Gilman 2022)
Drug interactions
- Clobazam: in 13 children with epilepsy, the active metabolite N-desmethylclobazam rose by an average of 500%; the rise in clobazam itself (average 60%) was uncertain (confidence interval −2 to 91). In healthy volunteers, clobazam did not change and the metabolite rose ~3-fold (FDA/EMA). In 10 of 13 patients, side effects resolved when the clobazam dose was reduced (Geffrey 2015, PMID 26114620)
- No short-term increase in side effects was seen in people taking benzodiazepines/antipsychotics (advanced cancer, Downs 2026, PMID 39539239)
- Alcohol: 200 mg CBD + alcohol was not clearly different from the impairment caused by alcohol alone (Consroe 1979, PMID 120541; 10 people, old and small)
- Pure oral CBD (15–1500 mg) did not cause THC-positive results on roadside saliva tests (McCartney 2022, PMID 34412166)
Abbreviations: RCT, randomized controlled trial (a study in which participants are assigned to groups by chance); placebo, an inactive substance; SMD, OR and RR, effect measures used in analyses that pool studies; CYP, liver enzymes that break down medicines.
If you are considering CBD
- Talk to your doctor about long-lasting insomnia; there may be an underlying cause.
- If you take sleep medicines, sedatives or other regular medicines, go over CBD with your doctor or pharmacist; do not stop your current treatment on your own.
- Check the label and the certificate of analysis; THC-containing products can cause sleepiness the next day and can affect driving.
- If you are older or take many medicines, extra care is needed; sleep studies were mostly done in young and middle-aged people.
Choose your age group, medicines and situation to prepare a short summary you can take to your doctor. Nothing you enter is sent anywhere.
Bottom line
As of October 2026, research has not shown that pure CBD clearly improves insomnia. With THC-containing products, sleep may feel better, but their effects on measured sleep and on the next day must also be taken into account. In sleep apnea, small and short studies with dronabinol found fewer breathing pauses, but there are no long-term data; the American Academy of Sleep Medicine does not recommend its use, and these products do not replace CPAP. There is very little controlled evidence for restless legs. In nightmares linked to post-traumatic stress disorder, the only large study with dronabinol is positive, but there is no second study confirming it. Larger and longer studies will make the picture clearer.
Frequently asked questions
Does CBD oil work for insomnia?
For pure CBD, no clear benefit has been seen so far. In controlled studies, there was no clear difference between people taking CBD and those taking an inactive pill (placebo) in time to fall asleep, night awakenings or insomnia severity. The evidence is considered weak.
Are THC-containing products better for sleep?
With THC-containing products, people more often reported that their sleep was better. But measurements did not always confirm this feeling: in a single-dose lab study, THC and CBD together reduced total sleep and dream sleep, and in a two-week study, sleep measured in the lab did not change. THC also carries risks related to addiction and driving: in a study of people who got a medical cannabis card for pain, insomnia, anxiety or depression, symptoms eased in those who applied for insomnia, but over 12 weeks cannabis use disorder developed in 17 percent of those who got the card right away and in 9 percent of those who waited (most in those who applied for anxiety or depression).
Does CBD oil cause sleepiness the next day?
In a study where pure CBD was taken every night, daytime mental performance was not impaired. When THC and CBD were taken together, mild sleepiness was reported the next day; most tests done at least 9 hours later, and a driving simulation, showed no impairment. In an old study of healthy volunteers, however, 15 mg of THC taken before bed led to sleepiness and weaker memory the next morning; in a 1973 study, 30 mg of THC caused a 'hangover' that lasted into the next day.
Can CBD be used with sleep medicines?
When used together with sleep medicines, sedatives or similar drugs, sleepiness may increase and blood levels of some medicines may rise. That is why this decision needs to be made together with your doctor.
Can CBD oil be obtained with a prescription for insomnia in Turkey?
In Turkey, products derived from cannabis are regulated by the Kenevirden Elde Edilen Ürünlere Dair Yönetmelik (Regulation on Products Derived from Hemp) dated January 31, 2026. These products, including CBD, may be sold only in pharmacies. Those classed as medicines and health products are dispensed with a prescription; the regulation does not state a prescription requirement for support products and cosmetics with a THC content of at most 0.3%. As of October 2026, there is no approved (licensed) CBD medicine in Turkey. If you are thinking of using it, talk to your doctor first.
Does CBD or cannabis help sleep apnea?
There is no study of CBD in sleep apnea. In a six-week, 73-person study with dronabinol, the synthetic form of THC, breathing pauses during sleep decreased compared with placebo and daytime sleepiness eased slightly at the high dose; but according to the study registry, most people on the high dose had sleepiness. Of two small studies combining dronabinol with other drugs, one found fewer apneas and the other found no improvement in the main measure. The studies are short, side effects are common, and the American Academy of Sleep Medicine recommends that cannabis products not be used for sleep apnea. These products do not replace treatment your doctor recommends, such as CPAP; if you are thinking of changing your treatment, talk to your sleep doctor first.
Does CBD work for restless legs syndrome?
There are very few controlled studies on this. In an analysis done afterward of a study in Parkinson’s patients, CBD did not reduce restless legs symptoms compared with placebo. In a small study with low-dose THC and CBD that had no control group, symptoms eased; a few case reports describe similar things. The guideline of the German sleep and neurology societies does not recommend treatment with cannabinoids. Two placebo-controlled studies are ongoing or about to start.
References
Show 48 references
- Linares 2018 (sleep). Double-blind, crossover RCT. PMID 29674967, doi:10.3389/fphar.2018.00315
- Narayan 2024 (JCSM). Parallel RCT, 1-week single-blind placebo run-in (8 people who responded to placebo during the run-in were removed before randomization). PMID 38174873, doi:10.5664/jcsm.10998, Daytime cognitive function and mood publication of the same trial: Narayan 2025, PMID 39153080, its findings are in this row’s outcome and side effect fields), ANZCTR ACTRN12620000070932 (prospectively registered)
- Wang 2025. Double-blind, crossover RCT, phase 2. PMID 39167421, doi:10.5664/jcsm.11324, NCT05233761, results in the registry)
- Kisiolek 2023. Randomized, placebo-controlled study. PMID 37836465, doi:10.3390/nu15194173
- Saleska 2024. Double-blind RCT, 6 arms, remote; no placebo arm. PMID 37162192, doi:10.1080/27697061.2023.2203221
- Shannon 2019. Retrospective case series. PMID 30624194, doi:10.7812/TPP/18-041
- Walsh 2021. Double-blind, crossover RCT. PMID 34115851, doi:10.1093/sleep/zsab149
- Ried 2023. Double-blind, crossover RCT. PMID 36539991, doi:10.1111/jsr.13793
- So-Ngern 2025. Placebo-controlled RCT. PMID 40430155, doi:10.3390/life15050727
- Suraev 2026. Crossover pilot RCT, HD-EEG. PMID 40631525, doi:10.1111/jsr.70124, ANZCTR ACTRN12619000714189 (prospectively registered). Next-day functioning publication of the same trial (secondary outcomes): Suraev 2024, PMID 38758300, no impairment compared with placebo on 27 of 28 cognitive and psychomotor tests or in a driving simulation, a small drop in accuracy on the easy Stroop task (−1.4%), a small increase in feeling of 'sedation' at hour 10, no difference in alertness and sleepiness scores
- Hausenblas 2025. Double-blind, crossover pilot RCT. PMID 39980821, doi:10.1002/hsr2.70481, ISRCTN 15022302
- Bonn-Miller 2024. Double-blind RCT, 5 arms. PMID 37796540, doi:10.1037/pha0000682, NCT05839964, after the study ended in December 2022, the primary measure in the registration is the same as in the publication: sleep quality, no results in the registry)
- Kolobaric 2024. Double-blind RCT, 5 arms. PMID 39204082, doi:10.3390/ph17080977, NCT05511818, 679-person registration covering several products and a placebo arm, August 2022, the registration date is written in two different ways in the publication)
- Lavender 2026. Double-blind, 3-arm crossover RCT, polysomnography. PMID 41698831, doi:10.1111/jsr.70284
- Chagas 2014 (RBD). Case series. PMID 24845114, doi:10.1111/jcpt.12179
- de Almeida 2021 (RBD). Double-blind RCT, phase 2/3. PMID 33754375, doi:10.1002/mds.28577, Exploratory restless legs syndrome analysis of the same trial: de Almeida 2023, PMID 35749710, no difference from placebo in symptom severity (IRLS) on primary and secondary outcomes, a post hoc analysis. Also a row in the Parkinson’s topic
- AminiLari 2022. Systematic review and meta-analysis (39 RCTs). PMID 34546363, doi:10.1093/sleep/zsab234
- da Silva 2025. Systematic review and meta-analysis. PMID 40929927, doi:10.1016/j.smrv.2025.102156
- Varela 2026 (Cochrane). Cochrane systematic review and meta-analysis (9 RCTs; 8 compared with placebo, 1 with amitriptyline). PMID 42863850, doi:10.1002/14651858.CD016216.pub2
- Velzeboer 2025. Systematic review and meta-analysis (18 studies, 9 in the meta-analysis). PMID 40967124, doi:10.1016/j.smrv.2025.102164
- Wilson 2026. Systematic review and meta-analysis (54 RCTs in mental health and substance use disorders). PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, A correction was published in the journal: Lancet Psychiatry 2026, PMID 42302809, online June 16, 2026), it corrects the axis of a figure and the study counts in the table, and the results did not change
- Carlini 1981. Placebo- and active drug (nitrazepam)-controlled crossover study (double blinding and randomization not stated in the abstract; one review reports it as a 'crossover trial'); the same publication also summarizes studies in healthy volunteers and in epilepsy. PMID 7028792, doi:10.1002/j.1552-4604.1981.tb02622.x
- Nicholson 2004. Double-blind, placebo-controlled, 4-period crossover study (sleep lab). PMID 15118485, doi:10.1097/01.jcp.0000125688.05091.8f
- Ware 2010. Double-blind, active drug (amitriptyline)-controlled, randomized crossover equivalence study. PMID 20007734, doi:10.1213/ANE.0b013e3181c76f70, NCT00381199, also a row in the fibromyalgia topic
- Gilman 2022. Pragmatic RCT (getting a medical cannabis card right away or after 12 weeks; 2:1 randomization; participants were not blinded, only assessors were blinded). PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36638745, in card holders, reported sleep quality was better on days cannabis was used, and frequency of use rose). Also a row in the pain, depression and substance use topics
- Kolobaric 2023. Double-blind, placebo-controlled, parallel 3-group, remote (online) RCT. PMID 37686820, doi:10.3390/nu15173788, NCT05511818, according to the publication, not this study’s own registration, Kolobaric 2024 in the table also cites the same template)
- Peball 2022. Post hoc sleep analysis of a double-blind, placebo-controlled, enriched randomized withdrawal trial (NMS-Nab). PMID 35937495, doi:10.1002/mdc3.13471, PMID 32757413, row in the Parkinson’s topic), NCT03769896, EudraCT 2017-000192-86, PMID 38491070, uncontrolled, 22 patients)
- Walczyńska-Dragon 2025. Sleep and migraine results of a double-blind, placebo-controlled, 3-group RCT (secondary publication of the same trial; the main publication examined pain, muscle tension and teeth clenching); according to this publication, the placebo gel was clear and the CBD gels slightly opaque, and according to the main publication, the CBD gels were slightly bitter (blinding may have been compromised; according to the authors, participants were not told about these differences and no one reported noticing their group). PMID 40732351, doi:10.3390/ph18071064, PMID 38592260, row in the topical CBD topic), NCT05562635, no sleep measure)
- Emerson 2026. Triple-blind, placebo-controlled, remote (online) RCT. PMID 41574318, doi:10.1159/000549902, NCT05088018
- Gournay 2026. Sleep results of a double-blind, placebo-controlled, 3-group RCT (the anxiety results of the same trial are in a separate publication). PMID 41678223, doi:10.1037/pha0000832, PMID 37552290, row in the anxiety topic), this publication is also in the anxiety table under the name 'Gournay 2026 (sleep results)'
- Kamoltham 2026. Phase 2, double-blind, double-dummy, active drug (lorazepam)-controlled, randomized equivalence (non-inferiority) study. PMID 41736083, doi:10.1186/s42238-026-00415-x, Thai Clinical Trials Registry TCTR20240718004 (after the study ended)
- Pakdee 2026. Open-label, randomized, 3-group parallel study (only assessors blinded; no placebo). PMID 41623556, doi:10.1016/j.sleepx.2026.100173, PMID 41756111, PMC12933466): they acknowledge as limitations that no sleep apnea screening was done and that the analysis relied on within-group before–after change
- Carley 2018 (PACE). Phase 2, multicenter, fully blinded, placebo-controlled, parallel 3-group RCT. PMID 29121334, doi:10.1093/sleep/zsx184, NCT01755091, PMID 29361189
- Walsh 2025. Double-blind, placebo-controlled, randomized crossover dose-finding study (single-blind placebo run-in). PMID 39589391, doi:10.1093/sleep/zsae276, ANZCTR ACTRN12620000916943, PMID 40328187
- Cousens 1973. Experimental dose study (three dose levels); randomization, placebo control and number of participants not in the abstract (one review refers to it as an RCT). PMID 4776660, doi:10.1007/BF00437513
- Prasad 2013. Open-label, single-center dose-escalation study (no control group). PMID 23346060, doi:10.3389/fpsyt.2013.00001, PMID 24426820
- Messineo 2023. Open-label, two-center, 4-period dose-escalation study (no placebo; comparison with baseline and with atomoxetine alone). PMID 36805833, doi:10.5664/jcsm.10528, NCT05101122
- Lillo Triguero 2026. Prospective, open-label exploratory study (no control group). PMID 42387200, doi:10.1007/s00415-026-13975-y
- Asim 2026. Systematic review and meta-analysis of RCTs (up to January 2025). PMID 42574897, doi:10.1016/j.sleep.2026.109193, PMID 42753382, contents could not be read)
- Drager 2023 (Brazilian Sleep Association). National clinical guideline (Brazilian Sleep Association; systematic literature searches, Oxford levels of evidence, expert voting). PMID 38370879, doi:10.1055/s-0043-1776281
- Ramar 2018 (AASM). Position statement (American Academy of Sleep Medicine). PMID 29609727, doi:10.5664/jcsm.7070, PMID 30353820, PMID 30353823, 30353829 (contents not read)
- Boylan 2024. Systematic review (no meta-analysis). PMID 39498540, doi:10.1002/phar.4622
- Saha 2026. Scoping review (PRISMA-ScR; up to April 2025; no meta-analysis). PMID 42617004, doi:10.4103/aian.aian_1168_25, PMID 28655453, 6 patients), PMID 31820197, 12 patients), NCT06570941
- Trenkwalder 2024 (German guideline). National guideline (German Sleep Society and German Neurological Society; abbreviated guideline). PMID 39501372, doi:10.1186/s42466-024-00353-0, Cannabinoids are not addressed in the American Academy of Sleep Medicine’s 2025 restless legs guideline (Winkelman 2025, PMID 39324694
- Koye 2026 (UK Medical Cannabis Registry). Prospective observational cohort (patient registry; no control group). PMID 42935025, doi:10.1002/npr2.70180, PMID 38337193, 61 patients, PMID 41662070, 124 patients, 18 months)
- Roepke 2026. Multicenter (Germany), double-blind, placebo-controlled, parallel-group RCT (phase 2). PMID 42557458, doi:10.1038/s41591-026-04546-9, NCT04448808, October 28, 2026), PMID 37147642, also a row in the PTSD topic
- Jetly 2015. Double-blind, placebo-controlled, randomized crossover pilot study. PMID 25467221, doi:10.1016/j.psyneuen.2014.11.002, Health Canada registration, also a row in the PTSD topic
- Morgenthaler 2018 (AASM). Position statement (American Academy of Sleep Medicine; literature search March 2009–August 2017 and expert opinion; a position statement instead of a guideline because the evidence is limited). PMID 29852917, doi:10.5664/jcsm.7178, Also a row in the PTSD topic, PMID 32088375
Points that could not be verified from the full text
- The correction to Wilson 2026 published in the journal was read on October 29, 2026: only the axis of one figure and the study counts in a table were corrected, and the insomnia results did not change. Which 10 studies Asim 2026 pooled could not be seen because the full text is not open access, so its overlap with the studies in the table is not known.
Research history
Here we record what changed on this page, when and why, with dates. The newest change is at the top.
October 2026 supplementary review: sources found for this page during the searches for other topics were read and added to the page. The product type of the review pooling cannabinoid trials in disturbed sleep (AminiLari 2022) was changed to 'mixed', because besides THC-containing products it also covers nabilone and CBDV studies; an internal note in a dose field was rewritten in reader language; the Brazilian Academy of Neurology’s 2025 Parkinson’s guideline assessment of CBD in REM sleep behavior disorder was added to the text; in three rows from the same Brazilian research group, the authors’ patent and company ties were written consistently with the other rows. No studies were added to the table. The conclusion and strength of evidence did not change.
October 2026 evidence search: PubMed, Cochrane and ClinicalTrials.gov were searched systematically, and the findings were reread from primary sources in an independent check; by the founder’s scope decision, sections on sleep apnea and restless legs syndrome were opened on this topic. 27 studies were added to the table. In insomnia: a 2-week study with pure CBD in worried people (no different from placebo), a small 1981 study and a CBD gel applied inside the mouth; with THC-containing products, a sleep lab study in healthy volunteers, the cannabis card trial, two studies from Thailand and a multi-ingredient supplement study; nabilone and CBG studies; a meta-analysis, the Brazilian Sleep Association guideline and a patient registry from the UK. In sleep apnea, four studies with dronabinol, the American Academy of Sleep Medicine position statement and a systematic review; in restless legs, an open-label study, a review and the German guideline. In nightmares linked to post-traumatic stress disorder, two placebo-controlled studies with dronabinol and nabilone and the American Academy of Sleep Medicine nightmare position statement (also on the PTSD page) were added. Three rows that were secondary publications of the same trials, and a Parkinson’s trial in which sleep was only a secondary measure, were removed from this topic’s table; the findings of the secondary publications were moved to the main rows. Corrected in existing rows: that the primary measure was negative in a CBN study (Bonn-Miller 2024), that superiority over placebo stated in the abstract of a formula study was not seen in the full-text analysis (Hausenblas 2025), participant numbers, durations, registration numbers and company ties. The conclusion and strength of evidence did not change.
Related studies: Carlini 1981, published 1981 (PMID 7028792, doi:10.1002/j.1552-4604.1981.tb02622.x); Nicholson 2004, published June 2004 (PMID 15118485, doi:10.1097/01.jcp.0000125688.05091.8f); Ware 2010, published February 2010 (PMID 20007734, doi:10.1213/ANE.0b013e3181c76f70, NCT00381199, also a row in the fibromyalgia topic); Gilman 2022, published March 1, 2022 (PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36638745, in card holders, reported sleep quality was better on days cannabis was used, and frequency of use rose). Also a row in the pain, depression and substance use topics); Kolobaric 2023, published August 30, 2023 (PMID 37686820, doi:10.3390/nu15173788, NCT05511818, according to the publication, not this study’s own registration, Kolobaric 2024 in the table also cites the same template)); Peball 2022, published August 2022 (PMID 35937495, doi:10.1002/mdc3.13471, PMID 32757413, row in the Parkinson’s topic), NCT03769896, EudraCT 2017-000192-86, PMID 38491070, uncontrolled, 22 patients)); Walczyńska-Dragon 2025, published July 19, 2025 (PMID 40732351, doi:10.3390/ph18071064, PMID 38592260, row in the topical CBD topic), NCT05562635, no sleep measure)); Emerson 2026, published 2026 (PMID 41574318, doi:10.1159/000549902, NCT05088018); Gournay 2026, published April 2026 (PMID 41678223, doi:10.1037/pha0000832, PMID 37552290, row in the anxiety topic), this publication is also in the anxiety table under the name 'Gournay 2026 (sleep results)'); Kamoltham 2026, published February 24, 2026 (PMID 41736083, doi:10.1186/s42238-026-00415-x, Thai Clinical Trials Registry TCTR20240718004 (after the study ended)); Pakdee 2026, published December 2026 (journal volume; online earlier) (PMID 41623556, doi:10.1016/j.sleepx.2026.100173, PMID 41756111, PMC12933466): they acknowledge as limitations that no sleep apnea screening was done and that the analysis relied on within-group before–after change); Carley 2018 (PACE), published January 1, 2018 (PMID 29121334, doi:10.1093/sleep/zsx184, NCT01755091, PMID 29361189); Walsh 2025, published April 11, 2025 (PMID 39589391, doi:10.1093/sleep/zsae276, ANZCTR ACTRN12620000916943, PMID 40328187); Cousens 1973, published December 20, 1973 (PMID 4776660, doi:10.1007/BF00437513); Prasad 2013, published 2013 (PMID 23346060, doi:10.3389/fpsyt.2013.00001, PMID 24426820); Messineo 2023, published July 1, 2023 (PMID 36805833, doi:10.5664/jcsm.10528, NCT05101122); Lillo Triguero 2026, published July 2, 2026 (PMID 42387200, doi:10.1007/s00415-026-13975-y); Asim 2026, published December 2026 (journal issue; online earlier) (PMID 42574897, doi:10.1016/j.sleep.2026.109193, PMID 42753382, contents could not be read)); Drager 2023 (Brazilian Sleep Association), published October 2023 (PMID 38370879, doi:10.1055/s-0043-1776281); Ramar 2018 (AASM), published April 15, 2018 (PMID 29609727, doi:10.5664/jcsm.7070, PMID 30353820, PMID 30353823, 30353829 (contents not read)); Boylan 2024, published November 2024 (PMID 39498540, doi:10.1002/phar.4622); Saha 2026, published July 1, 2026 (PMID 42617004, doi:10.4103/aian.aian_1168_25, PMID 28655453, 6 patients), PMID 31820197, 12 patients), NCT06570941); Trenkwalder 2024 (German guideline), published November 6, 2024 (PMID 39501372, doi:10.1186/s42466-024-00353-0, Cannabinoids are not addressed in the American Academy of Sleep Medicine’s 2025 restless legs guideline (Winkelman 2025, PMID 39324694); Koye 2026 (UK Medical Cannabis Registry), published December 2026 (online October 26, 2026) (PMID 42935025, doi:10.1002/npr2.70180, PMID 38337193, 61 patients, PMID 41662070, 124 patients, 18 months)); Roepke 2026, published September 2026 (online August 5, 2026) (PMID 42557458, doi:10.1038/s41591-026-04546-9, NCT04448808, October 28, 2026), PMID 37147642, also a row in the PTSD topic); Jetly 2015, published January 2015 (PMID 25467221, doi:10.1016/j.psyneuen.2014.11.002, Health Canada registration, also a row in the PTSD topic); Morgenthaler 2018 (AASM), published June 15, 2018 (PMID 29852917, doi:10.5664/jcsm.7178, Also a row in the PTSD topic, PMID 32088375)
A new Cochrane review (October 2026) and a review pooling sleep lab studies were added; the insomnia finding of a meta-analysis pooling cannabinoid studies in mental health conditions (sleep time measured with an electronic device got longer) was added to the table. The effect of THC-containing products on measured sleep was separated by type of measurement: the drop in total sleep and REM is the finding of a single-dose pilot study. It was corrected that a CBD study in healthy young people did not show superiority over placebo on the overall sleep score. The conclusion and strength of evidence did not change.
Older changes (4)
The names of the finding labels were simplified: the "No benefit seen" label on this page became "No effect found". The assessment did not change.
Newly published and previously missed clinical studies were searched in PubMed and ClinicalTrials.gov. 2 studies added: Kisiolek 2023 and So-Ngern 2025. The conclusion and strength of evidence did not change.
Related studies: Kisiolek 2023, published September 27, 2023 (PMID 37836465, doi:10.3390/nu15194173); So-Ngern 2025, published April 30, 2025 (PMID 40430155, doi:10.3390/life15050727)
The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: duration, dose, side effect and product details in the study table; drug interaction notes; the dose range in the studies. No point remains that could not be verified from the full text (previously 2 items). The year of 7 publications named on the page was corrected to the journal’s print year instead of the online publication year. The conclusion and strength of evidence did not change.
Page published. In this first assessment, 20 studies were reviewed.