What does the research say?
In a study of 16 untreated people with high blood pressure, when CBD was taken for one day, 24-hour systolic blood pressure (the top number) measured about 5 mmHg lower than with an inactive substance (placebo). In another study of 70 people with mild to moderate high blood pressure, systolic blood pressure fell by 4.76 mmHg over 2.5 weeks; however, increasing the dose gave no additional benefit, and arterial stiffness did not change. Both studies came from the same research group; both used a patented CBD formulation designed for better absorption, and both were funded by the company that owns the formulation. The abstract of the 70-person study does not state whether the 4.76 mmHg drop was compared with placebo or with the start of the study.
In studies of healthy men, a single dose of CBD lowered resting systolic blood pressure by about 6 mmHg but raised heart rate. When CBD was taken every day for a week, the drop seen after the first dose had disappeared by the seventh day; in other words, the body may have gotten used to it. The drop in blood pressure measured during stress, however, persisted.
In 109 patients with inflammation of the heart muscle (myocarditis), pharmaceutical-grade CBD was compared with placebo for 12 weeks; there was no clear difference in the main heart MRI measurements, and improvement was seen only in some exploratory measurements (for example, left ventricular mass). In a study without a comparison group in 27 patients with recurrent inflammation of the sac around the heart (pericarditis), pain and the inflammation marker CRP decreased. Both studies were funded by the drug's manufacturer. These studies used very high doses of pharmaceutical-grade CBD under a doctor's supervision; the results cannot be applied to CBD oils sold on the market.
All of these studies are small and short. There is no research showing that CBD keeps blood pressure under control over the long term or prevents events such as heart attack or stroke. So the findings are interesting, but they are not evidence of a treatment.
The results of the other small studies in healthy volunteers are mixed. In 17 people who did not use cannabis, a single dose of 200–800 mg CBD lowered blood pressure slightly. In four studies, however, CBD did not change blood pressure or heart rate compared with an inactive substance (placebo): 100 mg a day for 12 weeks, a single 100 mg dose by mouth or vaporized, a single 300 mg dose before running, and a single 200–800 mg dose in people who regularly smoke marijuana. A 2026 systematic review of four studies that measured blood pressure says the drop was seen mostly at higher doses, under stress or during sleep, and that the studies were small and short.
No study has aimed to treat blood pressure with THC-containing products. In controlled studies, THC raised heart rate and, in some people, caused a drop in blood pressure on standing up and dizziness. In a few small studies of patients with high blood pressure, blood pressure fell or did not change after THC products; because these studies were very small or had no comparison group, they do not count as evidence of a treatment. In a 1975 study of 10 patients with chest pain (angina) that did not use a placebo, one marijuana cigarette cut in half the time patients could exercise before the pain began. Information on heart attack and stroke comes from large observational studies: in most of them, these events were more common in people who used cannabis, while some studies with long follow-up found no link. Studies of this kind do not show cause and effect.
Strength of evidence: ●●○○ Weak evidence. Finding: May help a little. What does this mean?
Ongoing research on this topic
Trials testing CBD for this topic on ClinicalTrials.gov: 1 under way (1 recruiting); results are awaited from 1 that ended in the last two years. A trial being under way does not show that CBD works.
- NCT06708299: Phase 3, recruiting, target 110 participants
- NCT04693884: Early phase 1, completed, results awaited, 22 participants
Possible side effects and drug interactions
In the studies, CBD was generally well tolerated; no new heart rhythm problems were seen in people with high blood pressure, and in the 70-person study there were no changes in liver values and no serious side effects. In healthy men, a single dose raised heart rate. In the heart muscle inflammation study, side effects were more common in the CBD group (77% vs. 60%), and most were mild; in the CBD group, a recurrence of myocarditis and a heart rhythm problem (ventricular tachycardia) in one patient each, and a rise in liver enzymes in two patients, were recorded as serious events.
In people who take blood pressure medicine or whose blood pressure is already low, CBD may cause dizziness and an excessive drop in blood pressure. CBD can also slow the breakdown of some medicines in the body: in one study, a CBD-dominant extract that also contained THC increased the amount of the blood pressure medicine losartan in the body by 77%.
THC-containing products clearly raise heart rate and, especially in people who are not used to them, can cause dizziness and a drop in blood pressure on standing up. In a pooled analysis of RCTs of medical cannabinoids, a drop in blood pressure on standing was about 3 times more common than with placebo.
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 |
|---|---|---|---|
| Losartan, Blood pressure medicines (general) | Caution | Blood pressure medicines and low blood pressure: CBD can lower blood pressure by a few mmHg; if you take blood pressure medicine or your blood pressure is low, dizziness and a drop in blood pressure may occur. In a study with a single dose of a CBD-dominant cannabis extract, the blood level of losartan went up, but its conversion to the breakdown product that provides most of its effect went down; the net effect of this on blood pressure is not known. Talk to your doctor. | PMID 37093160, PMID 28614793, PMID 37313955, Losartan prescribing information §12.3, dailymed.nlm.nih.gov |
To check interactions with the medicines you take: CBD drug interaction checker.
How was CBD used in studies?
In the studies, CBD was taken by mouth. The doses used were a single dose of 600 mg (study dose; not a personal recommendation), 600 mg a day for one week (study dose; not a personal recommendation), 150 mg every 8 hours for 24 hours (study dose; not a personal recommendation) and 225–450 mg a day for 5 weeks (study dose; not a personal recommendation). In the 70-person study, increasing the dose gave no additional benefit. In the other studies with healthy volunteers, the doses were a single dose of 100–800 mg and 100 mg a day for 12 weeks (study dose; not a personal recommendation); in most of these studies, blood pressure did not change differently from an inactive substance.
Study details (for health professionals)
In small RCTs, pure CBD lowered blood pressure by a few mmHg (about 5 mmHg in 24-hour systolic pressure); increasing the dose gave no additional benefit. In healthy men, the drop after the first dose disappeared within 7 days (tolerance), and a single dose raised heart rate. The results of the other small RCTs in healthy volunteers are mixed: in 17 people who did not use cannabis, a single dose of 200–800 mg CBD lowered blood pressure slightly; in four studies that gave 100 mg a day for 12 weeks, a single 100 mg dose by mouth or vaporized, a single 300 mg dose, and a single 200–800 mg dose in people who regularly smoke marijuana, blood pressure and heart rate did not change differently from placebo. A 2026 systematic review of four RCTs that measured blood pressure says the drop was seen at higher doses and especially under stress or during sleep, and that the studies were small and short. The two RCTs in patients with high blood pressure came from the same research group; both used a patented CBD formulation designed for better absorption, and both were funded by the company that owns the formulation. In the abstract of the 70-person study, it is not clear whether the 4.76 mmHg drop was compared with placebo or with baseline. The effect is small and short-lived; there are no data showing an effect on heart events (stroke, heart attack). This is not evidence of a treatment. In heart inflammation, pharmaceutical-grade CBD (up to 20 mg/kg/day) was tested in two phase 2 studies: in acute myocarditis (109 people, 12 weeks), the primary MRI measurements were no different from placebo; in recurrent pericarditis (27 people, uncontrolled), pain and CRP decreased. Both studies were funded by the drug's manufacturer; in the myocarditis study, the registered primary outcome, extracellular volume percentage, also showed no difference. A placebo-controlled phase 3 study in recurrent pericarditis is ongoing (NCT06708299, October 2026). The same medicine was also compared with placebo in 90 people hospitalized with COVID-19 who had cardiovascular disease or risk factors; the study was stopped early because not enough patients could be enrolled, and it was not published in a peer-reviewed journal. According to the registry results, the combined outcome of death, intensive care or breathing support, and cardiovascular complications occurred in 3 of 45 people in the CBD group and in 2 of 45 in the placebo group (the difference was not significant; the study was not large enough to show a difference). Serious side effects occurred in 5 people in the CBD group and 4 in the placebo group; among those in the CBD group there was one case each of heart failure and QTc prolongation, and 2 people in the placebo group died (the groups were not compared statistically for side effects; the numbers are small). These are not approved uses. No study has aimed to treat blood pressure or heart disease with THC-containing products. In controlled studies, THC raised heart rate (by an average of 8 beats/min in a pooled analysis) and could cause a drop in blood pressure on standing up (relative risk 3.16 in RCTs of medical cannabinoids); in a 1975 study of 10 patients with angina that did not use a placebo, it brought on chest pain earlier during exercise. In a few small studies of patients with high blood pressure, blood pressure fell or did not change after THC products; these are very small studies or studies without a comparison group. In meta-analyses of observational studies, cannabis use was linked to acute coronary syndrome (relative risk 1.29), stroke (1.20; 1.37 in another meta-analysis) and atrial rhythm disorders (odds ratio 1.71); in a meta-analysis based on cohorts with long follow-up, the link was not significant for heart attack and stroke individually, and in some cohorts with long follow-up (CARDIA, Swedish conscripts, veterans with heart disease, UK Biobank), no link was found. These studies do not show cause and effect. Similar links are seen in people who use medical cannabis: in Denmark, among chronic pain patients starting medical cannabis by prescription, new heart rhythm problems in the first 6 months (0.8% vs. 0.4%), and in Canada, among people authorized to use medical cannabis, emergency visits or admissions for heart attack-like events or stroke (hazard ratio 1.44) were more common. October 2026 search (PubMed, Cochrane, ClinicalTrials.gov): 19 controlled studies with cannabinoids on this topic (11 with CBD, one of which used a product with an unclear THC content; 8 with THC-containing products) and 9 systematic reviews were found; these appear in the table below, together with 2 uncontrolled studies and 10 observational studies. There is no Cochrane review on this topic; the many older laboratory studies measuring THC's effect on heart rate and the blood pressure data measured in CBD anxiety laboratory studies are included not one by one but through the meta-analyses that combine them.
Evidence assessment: Weak (2 small RCTs with pure CBD in high blood pressure, 16 and 70 people, at most 5 weeks, both from the same research group and with the same company's formulation; 7 small RCTs with CBD in healthy volunteers, with mixed results; 1 phase 2 RCT in heart muscle inflammation, with a negative main result; 1 phase 2/3 RCT in patients hospitalized with COVID-19 who had cardiovascular risk, stopped early and with results only in the registry, with no difference in the main outcome)
CBD alone
Pure CBD may lower blood pressure by a few mmHg: there are 2 small RCTs in high blood pressure (16 and 70 people, at most 5 weeks; both from the same research group, using the same company's patented formulation). In healthy people, results are mixed: in some studies blood pressure fell slightly (in one, the effect disappeared within a week), and in others it did not change at all. In heart muscle inflammation, a 109-person phase 2 RCT found the main MRI measurements no different from placebo. This is not evidence of a treatment; for people taking blood pressure medicine, it is a drug interaction issue.
Products containing THC
No study has aimed to treat high blood pressure or heart disease with THC-containing products; the information we have is about safety. In controlled studies, THC raised heart rate (by an average of 8 beats/min in a pooled analysis) and, in some people, caused a drop in blood pressure on standing up and dizziness. In a few small studies of patients with high blood pressure, blood pressure fell or did not change after THC products; because these studies were very small or had no comparison group, they do not count as evidence of a treatment. In a 1975 study of 10 patients with chest pain (angina) that did not use a placebo, one marijuana cigarette cut in half the time patients could exercise before the pain began. In most large observational studies, cannabis use was linked to heart attack, stroke and atrial rhythm problems (in a 2025 meta-analysis, relative risk 1.29 for heart attack and similar events and 1.20 for stroke); in two large cohorts there was no link with new high blood pressure, and in some studies with long follow-up there was no link with heart events. These are association studies; they do not show cause and effect, and most concern smoked cannabis.
Evidence: Insufficient: there are no treatment studies of THC-containing products for blood pressure or heart disease. Information pointing to harm comes from controlled laboratory studies (raised heart rate, a drop in blood pressure on standing) and large observational studies; observational findings are associations and do not show cause and effect
Dose range in studies
In the studies, 600 mg as a single dose, 600 mg/day (7 days), 450 mg/day (24 hours), 225–450 mg/day (5 weeks); in the heart inflammation studies, 5–20 mg/kg/day; in the other studies in healthy volunteers, a single dose of 100–800 mg and 100 mg/day (12 weeks)
Starting dose and titration
In Dujic 2024, an increase from 225–300 mg/day to 375–450 mg/day (no additional benefit)
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 |
|---|---|---|---|---|---|---|
| Jadoon 2017 Double-blind, crossover RCT | 9 Healthy men | Pure CBD | 600 mg single dose | Single dose | Resting systolic pressure fell by about 6 mmHg; heart rate rose. In the handgrip and cold water stress tests, systolic blood pressure was also about 5–6 mmHg lower than with placebo. CBD and placebo were supplied by GW Pharma, which did not fund the study | PMID 28614793, doi:10.1172/jci.insight.93760 |
| Sultan 2020 Double-blind, parallel RCT | 26 (13 CBD, 13 placebo) Healthy men | Pure CBD | 600 mg/day | 7 days | After the first dose, resting mean arterial pressure fell by 2 mmHg compared with placebo (95% CI −3.6 to −0.3); by day 7 this effect had disappeared (tolerance); there was also no difference in 24-hour ambulatory blood pressure measured on day 6. Systolic blood pressure during stress was 6 mmHg lower after the first dose and 5.7 mmHg lower on day 7. In the CBD group, arterial stiffness decreased and the function of the inner lining of blood vessels (endothelial function) improved on day 7; this is a within-group comparison with day 1 (6 people each for blood vessel function) | PMID 32128848, doi:10.1111/bcp.14225 |
| Dragun 2023 Double-blind, crossover pilot RCT | 16 (8 women) Untreated hypertension | Oral CBD (patented formulation designed for better absorption, DehydraTECH) | 150 mg × 3/day (every 8 hours) | 24 hours | 24-hour systolic pressure about 5 mmHg, mean arterial pressure about 3 mmHg and arterial stiffness about 0.7 m/s lower (p < 0.05); the drop was more pronounced during sleep. A pilot study lasting only 24 hours. According to the Europe PMC record, the funder was the company that owns the formulation, Lexaria Bioscience (the full text could not be read); same research group as Dujic 2024 (University of Split) Side effects: No new arrhythmia, well tolerated | PMID 37291376, doi:10.1007/s12325-023-02560-8 |
| Dujic 2024 (HYPER-H21-4) Triple-blind, crossover RCT | 70 Mild to moderate primary hypertension (untreated or taking blood pressure medicine), aged 40–70, Croatia | Patented oral CBD capsule designed for better absorption (DehydraTECH 2.0 CBD) | 225–300 mg a day by body weight (split into three) for 2.5 weeks, then 375–450 mg a day for 2.5 weeks Dose increase | 2 × 5 weeks | 24-hour systolic pressure −4.76 mmHg at 2.5 weeks; the dose increase gave no additional benefit; arterial stiffness did not change. The abstract does not say whether −4.76 mmHg is a difference from placebo or a change from baseline during the CBD period (the full text could not be read; secondary publications from the same trial report CBD's effects relative to baseline within the CBD period). The study was funded by the company that owns the formulation (Lexaria Bioscience); same research group as Dragun 2023 (University of Split) Side effects: No change in liver enzymes and no serious side effects | PMID 37093160, doi:10.1089/can.2022.0320, NCT05346562, protocol Kumric 2022, PMID 35887534, secondary publications from the same trial: Kumric 2023, PMID 36780785, Kumric 2023, PMID 37321059, Batinic 2023, PMID 37373421, Dujic 2025, PMID 39187263, Kumric 2025, PMID 41203237 |
| McNamara 2026 (ARCHER) Phase 2, multicenter, double-blind, placebo-controlled RCT | 109 randomized (56 CBD / 53 placebo); primary analysis in 99 patients with centrally confirmed myocarditis, extracellular volume measurable in 71 patients Acute myocarditis (inflammation of the heart muscle) within 10 days of diagnosis | Pharmaceutical-grade oral CBD solution | From 2.5 mg/kg twice daily to 10 mg/kg twice daily (20 mg/kg/day) Weekly increases; 10 mg/kg × 2 at week 3 | 12 weeks | Primary MRI measurements not significant: extracellular volume −3.7 mL (95% CI −7.4 to 0.1; p = 0.054; measurable in only 71 patients because of MRI quality), no difference in strain (p = 0.90). In the ClinicalTrials.gov record, the primary outcome is listed as extracellular volume percentage, and it too showed no difference (−0.87 points; p = 0.26); the mL analysis is listed in the registry as an analysis not prespecified (post hoc). The design paper does not state a unit, and the registry's version history could not be accessed; the article describes the percentage measure in a footnote as 'not an appropriate outcome measure'. Left ventricular mass was 9.2 g lower with CBD (p = 0.012; prespecified exploratory outcome). The study was funded by the manufacturer, Cardiol Therapeutics; 15 of 16 authors have ties to the company (3 are company employees) Side effects: At least one side effect in 76.8% with CBD and 60.4% with placebo, mostly mild; serious events with CBD included a recurrence of myocarditis, ventricular tachycardia and a rise in liver enzymes (one patient each) | PMID 41711722, doi:10.1093/eschf/xvaf034, NCT05180240, June 17, 2026), design paper McNamara 2024, PMID 38937900 |
| Haney 2016 Double-blind, placebo-controlled, within-subject (crossover) laboratory RCT; multicenter | 31 completed (17 men, 14 women); 50 enrolled according to the registry Non-treatment-seeking, healthy volunteers who regularly smoke marijuana (US) | Oral CBD capsule (according to the registry, 200 mg CBD and lactose per capsule); 90 minutes later, a marijuana cigarette (5.3–5.8% THC) or a THC-free placebo cigarette | A single dose of 0, 200, 400 or 800 mg CBD | 8 sessions, a single dose in each session | CBD alone (with the placebo cigarette) did not significantly change cardiovascular measurements or subjective effects. Active marijuana raised heart rate (in the registry results, 15 minutes after smoking, 79 beats/min without CBD and 79–81 with 200–800 mg CBD; 64–65 beats/min with the placebo cigarette); no dose of CBD changed this rise or marijuana's pleasurable effects. Blood pressure values are not in the abstract or the registry Side effects: No serious side effects in the registry; other side effects in 1–8 of 50 people per condition | PMID 26708108, doi:10.1038/npp.2015.367, NCT01844687, secondary analysis of the same trial: Babalonis 2017, PMID 28088032 |
| Bell 2025 Randomized, crossover, placebo-controlled pilot study (triple-blind according to the registry; according to the article, all 12 people correctly guessed which day they took CBD) | 12 (4 men, 8 women) Healthy young adults who run regularly (US) | CBD isolate capsules (100 mg CBD per capsule, no THC; in grape seed oil; Procana) | A single dose of 300 mg (3 capsules), 2 hours before running | Single dose, on two separate days | Resting systolic blood pressure measured before the run was numerically lower on the CBD day, but the difference was not significant (p = 0.10); diastolic blood pressure (p = 0.50) and heart rate variability were also no different from placebo. Ratings of feeling calmer and more relaxed were higher on the CBD day; no difference in running time. A very small study, and blinding was broken (all 12 people correctly guessed the CBD day) Side effects: No difference in digestive complaints | PMID 41515147, doi:10.3390/nu18010029, NCT06364254 |
| Mastrofini 2024 Double-blind, placebo-controlled, parallel RCT | 56 randomized (28/28); 54 completed Healthy young adults (mean age 25; people with uncontrolled or controlled high blood pressure were not enrolled), US | Hemp-derived CBD oil (50 mg CBD per mL, THC less than 0.3%) | 2 × 50 mg a day (100 mg/day), under the tongue | 12 weeks (90 days) | No time- or group-related differences in heart rate or systolic and diastolic blood pressure (p > 0.05). Immune and inflammation markers, stress, sleep and mood were no different from placebo; a pain indicator measured in urine rose less in the CBD group. The study was funded by a CBD company (CBD Industries); a CBD brand is mentioned in the acknowledgments Side effects: Safe and well tolerated according to the article | PMID 38904150, doi:10.1080/15502783.2024.2370430 |
| Arout 2022 Double-blind, placebo-controlled, within-subject (crossover) outpatient laboratory study (PubMed publication type: RCT) | 17 (8 men, 9 women) Healthy volunteers who do not use cannabis (US) | Oral CBD (product details not in the abstract) | A single dose of 0, 200, 400 or 800 mg | A single dose in each session (4 dose conditions) | The primary question was pain: in the cold water pain test, CBD did not consistently change pain threshold or tolerance compared with placebo, and it increased pain intensity ratings at all doses. CBD was safe and well tolerated and caused a small drop in blood pressure (P < 0.01); the size of the drop, at which doses and in which measurement it was seen are not in the abstract (the full text could not be read). Funding and conflict of interest statements are not in the abstract Side effects: Safe and well tolerated according to the abstract | PMID 34223660, doi:10.1111/bcp.14973 |
| Spindle 2020 Double-blind, double-dummy, placebo-controlled, within-subject (crossover) laboratory study; session order randomized | 18 (9 men, 9 women) Healthy adults with cannabis experience but no use in the past 30 days (US) | Oral CBD (capsule, approved CBD solution or syrup) and vaporized pure synthetic CBD; also vaporized CBD-rich cannabis (10.5% CBD, 0.39% THC) | A single dose of 100 mg CBD (by mouth or vaporized); in the CBD-rich cannabis condition, 100 mg CBD + 3.7 mg THC | 4 sessions, a single dose in each; at least 1 week between sessions | 100 mg of pure CBD taken by mouth or vaporized did not change blood pressure or heart rate differently from placebo (peak systolic blood pressure 127.4 with placebo, 125.8 with oral CBD and 126.0 mmHg with vaporized CBD; peak heart rate 70.0, 71.0 and 68.7 beats/min). CBD-rich cannabis containing a little THC, however, raised heart rate (peak 76.2 beats/min; significant vs. placebo). No cognitive or psychomotor impairment. The row's product type reflects the pure CBD conditions; the result for CBD-rich cannabis is written separately. Government (NIDA, SAMHSA) funding; 1 of 9 authors had consulted for cannabis and cannabinoid companies Side effects: No unexpected or serious side effects | PMID 32247649, doi:10.1016/j.drugalcdep.2020.107937 |
| Luis 2026 Phase 2, open-label, multicenter (no control group) | 27 Symptomatic recurrent pericarditis (inflammation of the sac around the heart) | Pharmaceutical-grade oral CBD solution (100 mg/mL) | Up to 10 mg/kg twice daily (74% of patients at this dose, the others 5–7.5 mg/kg × 2) Increase up to the highest tolerated dose | 8 weeks + 18-week extension (with existing medicines tapered) | Peak pain fell from 5.8 to 2.1; CRP returned to normal in 8 of 10 patients with high CRP; in the extension, 17 of 24 patients (71%) had no new attack; no control group. The study was funded by the manufacturer, Cardiol Therapeutics; 7 of 15 authors have ties to the company (3 are company employees; the statistical analyses were done by an organization funded by the company) Side effects: Serious side effects in 2 patients: in one, CBD was stopped because of a severe drug reaction (DRESS) possibly related to the drug; the events in the other were considered unrelated to the drug. 2 patients stopped because of side effects before week 8; across the whole study, the drug was stopped in 4 patients with side effects and reduced or paused in 8. Most common were diarrhea (56%), chest pain (37%) and rash (30%); no clinically important change in QTc | PMID 42432451, doi:10.1161/JAHA.125.047605, NCT05494788, October 20, 2025, in the registry, CRP normal at week 8 in 7 of 12 patients, in the article in 8 of 10 patients with high CRP), NCT06708299 |
| Sellers 2013 (QT study) Double-blind, placebo- and active drug (moxifloxacin)-controlled, four-arm parallel RCT (thorough QT study) | 258 Healthy volunteers | THC+CBD mouth spray (nabiximols, Sativex) | 8 sprays a day (recommended dose) or 24–36 sprays a day (3–4.5 times the recommended dose); comparisons: placebo spray, a single dose of 400 mg moxifloxacin | 5 days | At the recommended and very high doses, no effect on the QT/QTc interval, which reflects the heart's electrical recovery; no clinically important changes in heart rate, conduction or ECG morphology. The sponsor is the drug's manufacturer (Jazz Pharmaceuticals in the registry today); the authors' company ties are not given because the full text could not be read Side effects: In the very high dose arm, 19 people (25%) stopped because of intolerable side effects; 4 serious psychiatric events at the highest dose, so the dose was lowered to 24 sprays a day; at the recommended dose, side effects were similar to earlier studies | PMID 27121791, doi:10.1002/cpdd.36, NCT01322139 |
| Mathew 2003 Randomized, double-blind, placebo-controlled laboratory study | 29 Volunteers | Intravenous THC and marijuana cigarette | Dose not in the abstract | Single administration | Both intravenous THC and the marijuana cigarette caused dizziness on standing; it was severe in 28% of participants. In those with severe dizziness, brain blood flow and blood pressure while standing fell the most, and pulse first rose and then fell. Dizziness was not related to the blood THC level | PMID 12873621, doi:10.1016/s0091-3057(03)00086-8 |
| Laurentino 2026 Randomized, double-blind, placebo-controlled, crossover study | 18 Healthy adults (mean age 26; per the protocol, no cannabis use in the past 6 months), Brazil | Oral THC oil and full-spectrum CBD+THC oil | A single dose of 12.5 mg THC or 12.5 mg CBD + 12.5 mg THC | Single dose, on three separate days | Both oils raised heart rate compared with placebo (p < 0.05). Only with the THC oil did cardiac index increase and vascular resistance fall; responses were more limited with the CBD+THC oil. The abstract does not report blood pressure change separately | PMID 42660566, doi:10.1002/bcp.70793, Protocol: Fagundes 2025, PMID 41226928, the published analysis has three conditions), Brazilian registry RBR-3jsvtbr |
| Cheung 2024 Controlled crossover laboratory study (randomized and single-blind according to the registry; each participant received all three conditions) | 22 Healthy young adults who use cannabis regularly (Canada) | THC-rich cannabis (13.6% THC, less than 1% CBD) smoked or vaporized; CBD-rich cannabis (14.5% CBD, less than 1% THC) vaporized | 100 mg of dried cannabis in each condition | Single administration, on three separate days | THC-rich cannabis by either route raised heart rate (about +16–17 beats/min) and mean arterial pressure (+5–7 mmHg) (p < 0.0001); CBD-rich cannabis did not (+1 beat/min, +3 mmHg; p > 0.05). After inhalation, arterial stiffness increased and the heart's relaxation function decreased; these changes were related to the rise in heart rate. No difference between smoking and vaporizing | PMID 39575727, doi:10.1161/JAHA.124.037731, NCT04693884, a second publication from the same trial: Cheung 2025, PMID 41115058 |
| Elias 2026 (MARY-JANE) Prospective, randomized crossover pragmatic trial (a daily text message instructing "use" or "don't use"; no blinding) | 108 people; 713 cannabis days, 616 non-use days Adults who regularly smoke or vape cannabis, with no history of heart rhythm problems (US) | Inhaled cannabis that participants used themselves | The participant's usual use | 14 days, continuous ECG recording | The primary outcome, the daily number of premature beats, was 9% lower on cannabis days (ratio 0.91; 95% CI 0.85–0.98; p = 0.02); atrial premature beats decreased by 10%, and ventricular premature beats did not change. No difference in steps, sleep or glucose values. Adherence to the instructions was not complete; a withdrawal effect on non-use days in regular users may explain the result | PMID 42584385, doi:10.1016/j.jacc.2026.07.014, NCT06021613 |
| Rosa 2022 (SativexStroke) Secondary analysis of an RCT (double-blind, placebo-controlled, crossover); blood pressure and pulse were compared only between the first and last 5 days of the drug period (not with placebo; no comparison group); patients measured and recorded the values themselves every day | 34 (41 enrolled); 31 were taking blood pressure medicine, 12 a beta blocker Patients with muscle stiffness (spasticity) after stroke (Italy) | THC+CBD mouth spray (nabiximols) | Up to the highest tolerated dose, at most 12 sprays a day; a mean of 9 sprays at the end of the period (about 24 mg THC + 22 mg CBD) Gradual increase over 14 days | 1-month drug period | Blood pressure (systolic, diastolic and pulse pressure) and heart rate did not change during the drug period (all p ≥ 0.2); no relationship with the number of sprays. No heart rhythm problems, cardiovascular or cerebrovascular events were seen. In the main trial, there was no difference in muscle stiffness compared with placebo. The manufacturer (GW Pharma) supplied the drug and placebo free of charge; a drug company (Almirall) covered the insurance and 40% of the total cost; an investigator-initiated study, and 1 of 9 authors had received support from Almirall for other research Side effects: 2 serious events in the main trial, unrelated to the heart | PMID 36386386, doi:10.3389/fcvm.2022.990188, Main trial: Marinelli 2022, PMID 35812088 |
| Crawford and Merritt 1979 Controlled clinical study (comparison with a placebo cigarette; randomization not in the abstract) | 16 glaucoma patients (8 with high blood pressure) Patients with open-angle glaucoma; 8 with normal blood pressure, 8 with high blood pressure | Marijuana cigarette (2.8% THC) | One cigarette (amount not in the abstract) | Single administration, 3–4 hours of monitoring | There was no significant change with placebo. After inhaling THC, heart rate rose in every patient (by 20–62 beats per minute), then systolic blood pressure fell by 12–52 mmHg and diastolic by 6–28 mmHg; the drop was larger and longer (3–4 hours) in those with high blood pressure. The drop in eye pressure paralleled the drop in blood pressure | PMID 468444 |
| Aronow 1975 Controlled comparison study (marijuana cigarette vs. high-nicotine tobacco cigarette; no placebo, randomization not in the abstract) | 10 Patients with exercise-induced chest pain (angina pectoris) | Marijuana cigarette | One cigarette (amount of THC not in the abstract) | Single administration | One marijuana cigarette increased the resting product of systolic blood pressure × heart rate (an indicator of the heart's oxygen demand) by 54% and shortened the exercise time until chest pain began by 50% compared with the measurement before smoking; with the high-nicotine cigarette, these figures were 36% and 23% (greater shortening with marijuana, p < 0.001). No placebo was used; an old study of 10 patients | PMID 1126112, doi:10.1002/cpt1975175549, The same group's study comparing marijuana with placebo marijuana: Aronow 1974, NEJM, PMID 4599385, full text could not be read), psychological outcomes in 10 angina patients with the same design: Gottschalk 1977, PMID 870096, hemodynamics in coronary disease: Prakash 1975, PMID 1097149 |
| Gonzalez 2026 Single-blind, placebo-controlled, fixed-order (placebo night first, then THC night) exploratory study; secondary analysis of a pilot study | 17 (9 who do not use cannabis, 8 regular users) Healthy adults (US) | Oral synthetic THC (dronabinol) | 10 mg 1 hour before bedtime | 3 nights in the laboratory; each administration a single dose | Resting blood pressure and pulse the next morning did not change. In people who do not use cannabis, on the morning after THC, dizziness was more common in the tilt-table (standing) test, and the response of diastolic blood pressure and heart rate to standing was reduced compared with the placebo morning; this difference was not seen in regular users. Very small and exploratory | PMID 42665978, doi:10.14814/phy2.71076, Sleep and heart rate variability in the same participants: Gonzalez 2026, PMID 41692699 |
| Roberts 2026 Systematic review (RCTs; numbers were not pooled because the studies differed) | 4 RCTs, 120 participants Adults with normal or high blood pressure | Oral CBD | 225–600 mg/day in the studies | Search September 2024; studies 2 hours–5 weeks | According to the review, all four RCTs (Jadoon 2017, Sultan 2020, Dragun 2023, Dujic 2024) reported a significant drop in systolic blood pressure compared with placebo; the drop was seen especially under stress and during sleep, and the largest effect was in short studies of 600 mg/day. In the review's own table, 24-hour blood pressure on day 6 in Sultan 2020 showed no difference and the resting effect had disappeared by day 7; for Dujic 2024, it is not stated that the values given are differences from placebo. Risk of bias mostly low. According to the authors, the studies were small, short and used different doses; liver safety is unclear; large, long studies are needed to establish its place in blood pressure treatment. The other healthy-volunteer RCTs in this table (Haney 2016, Arout 2022, Spindle 2020, Mastrofini 2024, Bell 2025) are not in the review; Bell 2025 was published after the search date. No funding, no conflicts of interest Side effects: Side effects mostly mild or moderate (nausea, diarrhea, fatigue); no serious cardiovascular events reported | PMID 42321899, doi:10.1186/s42238-026-00463-3, A meta-analysis published in Brazil that the review cites (Candeloro 2025) could not be found in PubMed or Europe PMC |
| Sultan 2017 Systematic review and meta-analysis (animal and human studies) | 25 publications; human data for 36 people for blood pressure and 87 for heart rate Studies in six species; in humans, healthy volunteers and some patient groups | CBD | In humans, a single dose between 320 μg/kg and 1,200 mg | Mostly single dose | Under normal conditions, single or repeated CBD did not change blood pressure or heart rate. In stress models (mostly animals), CBD reduced the stress-induced rise in blood pressure (mean difference −3.54 mmHg; 95% CI −5.19 to −1.9) and in heart rate. In humans, a single dose of CBD did not change blood pressure or heart rate in healthy volunteers under normal conditions or under stress (12 studies). Most studies were in animals; human data are scarce | PMID 28286481, doi:10.3389/fphar.2017.00081 |
| Sultan 2018 Systematic review and meta-analysis (animal and human studies) | 31 studies; 6 publications for heart rate in humans Animals and healthy volunteers who had not used cannabis | THC | Varied by study | Single dose and repeated dose | In humans, a single dose of THC raised heart rate (mean difference +8.16 beats/min; 95% CI 4.99–11.33; p < 0.00001), and the increase was dose-related; there were not enough data to pool blood pressure in humans. In animals, by contrast, THC lowered blood pressure and heart rate. According to the authors, human data are limited | PMID 29385080, doi:10.3390/ph11010013, The PubMed title says "Δ8", the article's own title and text say Δ9-THC |
| Watanabe 2021 Systematic review and meta-analysis (RCTs) | 47 RCTs, 2,800 patients Patients given cannabinoids for medical purposes; 45% of the studies had excluded people with cardiovascular disease | Medical cannabinoids (several product types) | Varied by study | Median duration of cannabinoid use 15.8 days (1–322 days) | Compared with placebo, cannabinoids increased the risk of a drop in blood pressure on standing (relative risk 3.16; 95% CI 2.27–4.40) and of low blood pressure (3.55; 1.45–8.71); the trend toward more palpitations/tachycardia was not significant (1.94; 0.81–4.64). No study reported a serious cardiovascular event; the studies were short, and heart patients were mostly excluded | PMID 33952424, doi:10.1016/j.japh.2021.03.013 |
| Storck 2025 Systematic review and meta-analysis (observational studies; risk of bias with ROBINS-E) | 24 studies (17 cross-sectional, 6 cohort, 1 case-control) People who use and do not use cannabis (one study of medical cannabis) | Cannabis use | Not applicable | Publications 2016–January 2023; search September 2023 | Cannabis use was associated with acute coronary syndrome (including heart attack; relative risk 1.29; 95% CI 1.05–1.59), stroke (1.20; 1.13–1.26) and cardiovascular death (2.10; 1.29–3.42); the result was similar with cohort studies only (1.32; 1.01–1.73). Most studies were cross-sectional; the association does not show cause and effect | PMID 40527600, doi:10.1136/heartjnl-2024-325429, PROSPERO CRD42023401401 |
| Sebastian 2025 Systematic review and meta-analysis (observational cohort data) | 17 studies, 1,902,481 people Adults aged 18–74; people who had ever used cannabis and people who had not | Cannabis use | Not applicable | Mean follow-up 8.5 years; search April 2024 | No significant association for heart attack (relative risk 1.25; 95% CI 0.91–1.71; p = 0.17) or stroke (1.38; 0.88–2.16; p = 0.16); a significant association for the combined outcome of any cardiovascular event (1.48; 1.16–1.90; p = 0.002). Large variation between studies | PMID 39800612, doi:10.1016/j.disamonth.2024.101849, PROSPERO CRD42024530366 |
| Ravi 2018 (systematic review) Systematic review (observational studies; strength of evidence graded) | 11 studies for cardiovascular outcomes (13 for risk factors) Adults using marijuana in any form | Marijuana use | Not applicable | Search 1975–September 2017 | The evidence on the association of marijuana with heart attack, stroke, cardiovascular death and death in heart patients was found to be insufficient; studies with long follow-up were limited by recall bias, poor measurement of use, low levels of use and low-risk participants | PMID 29357394, doi:10.7326/M17-1548, PROSPERO CRD42016051297 |
| Chye 2026 Systematic review and meta-analysis (large population studies) | 14 observational studies (5 prospective), 81,230,930 participants Adults in North America, Europe and Oceania | Cannabis use | Not applicable | Search April 2024 | Cannabis use was associated with atrial rhythm disorders (atrial fibrillation, flutter and tachycardia, supraventricular tachycardia) (odds ratio 1.71; 95% CI 1.1–2.6; p = 0.01); the association was stronger in people who also used other drugs (1.91). The association does not show cause and effect | PMID 40472951, doi:10.1016/j.hrthm.2025.05.062, PROSPERO CRD42023428219 |
| Ritson 2026 Systematic review and meta-analysis (observational studies) with genetic (Mendelian randomization) analysis | 32 studies, more than 100 million participants People who use and do not use illicit substances (administrative, hospital and population data) | Cannabis use (and other substances) | Not applicable | Search date not in the abstract | Cannabis use was associated with stroke risk (odds ratio 1.37; 95% CI 1.14–1.65); there was variation between studies and a small-study effect. In the genetic analysis, a predisposition to cannabis use disorder was associated with any stroke (1.11; 1.01–1.51) and with large-artery stroke (1.35; 1.01–1.80) | PMID 41566428, doi:10.1177/17474930261418926, PROSPERO CRD420251053702 |
| Abuhasira 2021 Prospective observational study (no comparison group; each patient compared with their own baseline) | 26 completed (38 enrolled) Patients over 60 with high blood pressure who were started on medical cannabis by a doctor (mean age 70; Israel) | Medical cannabis (mostly oil; in a 15-person subgroup, all products contained THC and CBD, THC 1–20%) | Product, route and dose were set by the treating doctor; in the 15-person subgroup, median daily THC 22 mg and CBD 30 mg, mostly oral oil (Abuhasira 2022) | 3 months | At 3 months, 24-hour systolic blood pressure fell by 5.0 mmHg and diastolic by 4.5 mmHg (both p < 0.001); the lowest values were 3 hours after cannabis. The proportion of people whose blood pressure dipped normally at night rose from 27% to 46%. No significant changes in blood tests, body measurements or ECG. Because there was no control group, it cannot be said that the drop was due to cannabis | PMID 33483174, doi:10.1016/j.ejim.2021.01.005, 15-person subgroup of the same cohort: Abuhasira 2022, PMID 36294974, THC/CBD ratios of the products) |
| Zongo 2021 Retrospective matched cohort (administrative health data and cannabis clinic records) | 18,653 medical cannabis patients, 51,243 matched controls Adults in Ontario (Canada) authorized to use medical cannabis and controls from the general population | Medical cannabis (product type and THC/CBD content not reported) | Not reported | Median follow-up 242 days (2014–2017) | Emergency visits or admissions for heart attack-like events (acute coronary syndrome) or stroke were more common in the cannabis group: 7.19 vs. 5.67 per 1,000 person-years (adjusted hazard ratio 1.44; 95% CI 1.08–1.93); for any cardiovascular event, 1.47 (1.26–1.72). In a 2026 analysis of the same data source, visits or admissions for heart failure were also more common (54,006 patients, 161,265 controls; hazard ratio 1.15; 1.06–1.25). Factors such as smoking, alcohol and blood pressure could not be adjusted for. Government (CIHR) funding; 2 of 7 authors have financial ties to a cannabis company or cannabis clinics; one of these authors and another author are on a grant partnered with a cannabis company, and one author is a former postdoctoral researcher supported by such a grant (these two authors state that they have no financial interests) | PMID 34507536, doi:10.1186/s12872-021-02229-6, Heart failure in the same data source: Dubois 2026, PMID 41497552, 15:100120, 2014–2019 cohort) |
| Holt 2024 Nationwide register-based matched cohort | 5,391 starting medical cannabis, 26,941 matched controls (from among 1.88 million chronic pain patients) Patients in Denmark starting prescription medical cannabis for the first time for chronic pain (median age 59; 63% women) | Prescription medical cannabis (product types not in the abstract) | Not reported (in the abstract) | 180 days and 1 year of follow-up (2018–2021) | In the first 180 days, new heart rhythm problems (atrial fibrillation/flutter, conduction disorders, tachycardias) were more common in the cannabis group: 0.8% vs. 0.4% (risk ratio 2.07; 95% CI 1.34–2.80); at 1 year, 1.36 (1.00–1.73). No significant difference for acute coronary syndrome (1.20 at 180 days; 0.35–2.04). Observational; absolute risk low | PMID 38200679, doi:10.1093/eurheartj/ehad834 |
| Keyhani 2025 Prospective cohort (THC Cohort; adjusted with survey weights and propensity scores) | 4,285 veterans; in the analysis, 1,015 who had smoked cannabis in the past 30 days and 3,122 who had not US veterans with coronary heart disease born 1950–1952 (aged 66–68) (2% women) | Smoking cannabis (any cannabis use in a separate analysis) | Not applicable | Mean follow-up 3.3 years | 563 events occurred. Smoking cannabis in the past 30 days was not associated with the combined outcome of heart attack, stroke and cardiovascular death (adjusted hazard ratio 0.87; 95% CI 0.61–1.24); there was also no association for any cannabis use. Use is self-reported | PMID 40686207, doi:10.1161/CIRCULATIONAHA.124.073193 |
| Mittleman 2001 Case-crossover study (each patient compared with themselves); multicenter heart attack onset study (Determinants of MI Onset Study) | 3,882 heart attack patients; 124 had smoked marijuana within the previous 1 year, 9 within 1 hour before the attack Patients with an acute heart attack (US) | Smoking marijuana | Not applicable | Interview a mean of 4 days after the attack | In the 60 minutes after smoking marijuana, the risk of a heart attack starting was 4.8 times the usual level (95% CI 2.4–9.5); this estimate is based on 9 patients who had smoked marijuana within 1 hour before the attack, and the risk then fell quickly. According to the authors, marijuana is a rare trigger of heart attack. In 18-year follow-up of the same cohort (2,097 patients aged 63 or younger, 109 of them marijuana users), death was 29% more common in marijuana users, but the difference was not significant (hazard ratio 1.29; 0.81–2.05; p = 0.28) | PMID 11401936, doi:10.1161/01.cir.103.23.2805, Long-term follow-up of the same cohort: Frost 2013, PMID 23351819, first follow-up analysis Mukamal 2008, PMID 18294478 |
| Jeffers 2024 Population-based cross-sectional study (US BRFSS health survey, 2016–2020) | 434,104 people (4% use cannabis daily, 7.1% occasionally) US adults aged 18–74 (27 states and 2 territories) | Cannabis use in the past 30 days (number of days) | Not applicable | Cross-sectional | After adjusting for tobacco use and other factors, daily cannabis use was associated with heart attack (adjusted odds ratio 1.25; 95% CI 1.07–1.46), stroke (1.42; 1.20–1.68) and the combined outcome (1.28; 1.13–1.44); for coronary heart disease, the association was borderline (1.16; 0.98–1.38). Among people who had never used tobacco, there were also associations with heart attack (1.49) and stroke (2.16); the odds rose as the number of days of use increased. Cross-sectional and self-reported; does not show cause and effect | PMID 38415581, doi:10.1161/JAHA.123.030178 |
| Corroon 2025 (CARDIA) Prospective cohort (CARDIA; weighted models for time-dependent factors) | 4,328 people at baseline, 2,810 at year 35 Black and White US young adults enrolled at age 18–30 without cardiovascular disease at baseline | Cumulative lifetime cannabis use (cannabis-years) | Not applicable (use was low: median 0.2 cannabis-years) | 35 years of follow-up | High blood pressure developed in 2,478 people; cumulative cannabis use was not associated with the risk of high blood pressure (hazard ratio 0.99; 95% CI 0.97–1.00; p = 0.18); the result did not change in sensitivity analyses. In a 2017 analysis of the same cohort (5,113 people, median 26.9 years, 215 events), cannabis use was also not associated with cardiovascular disease, stroke or cardiovascular death. Most participants used little. The first author is a paid board member of a company that makes CBD products from hemp (CV Sciences); the other 9 authors reported no ties; CARDIA is supported by the government (NHLBI) | PMID 40785536, doi:10.1161/HYPERTENSIONAHA.125.25005, Cardiovascular events in the same cohort: Reis 2017, PMID 28207342 |
| Haleem 2021 Population-based prospective survey cohort (NESARC, two waves) | 26,844 (people without high blood pressure at baseline) US adults | Cannabis use (lifetime, past 12 months and frequency) | Not applicable | 3 years | In the unadjusted analysis, new high blood pressure was less common in cannabis users, but this was due to age. After adjustment, neither lifetime use (odds ratio 0.89; 95% CI 0.77–1.02), nor use in the past 12 months (0.78; 0.56–1.09), nor frequency of use was associated with new high blood pressure. The blood pressure diagnosis is self-reported | PMID 33644920, doi:10.1111/dar.13266 |
| Falkstedt 2017 Population-based cohort (Swedish military conscription cohort, national registers) | 49,321 men Swedish men born 1949–1951 who underwent military conscription at age 18–20 | Cannabis use in youth (conscription questionnaire) | Not applicable | Follow-up to about age 60 | Cannabis use more than 50 times was associated neither with stroke before age 45 (hazard ratio 0.93; 95% CI 0.34–2.57) nor with stroke over the whole follow-up (0.95; 0.59–1.53). Although the risk of ischemic stroke appeared roughly doubled, it decreased after adjusting for tobacco and was not significant (1.47; 0.83–2.56). Smoking 20 or more cigarettes a day, by contrast, clearly increased the risk of stroke | PMID 28028147, doi:10.1161/STROKEAHA.116.015565 |
| Teraoka 2024 Prospective cohort (UK Biobank) | 150,554 (22.2% had used cannabis at least once) Middle-aged and older adults in the United Kingdom (mean age 63) | Cannabis use (number of lifetime uses) | Not applicable | Mean follow-up 6.1 years | In the adjusted analysis, neither occasional use (fewer than 100 times; hazard ratio 0.98; 95% CI 0.89–1.08) nor frequent use (1.03; 0.81–1.32) was associated with new atrial fibrillation. The route and amount of use could not be measured | PMID 38142832, doi:10.1016/j.hrthm.2023.12.008 |
Reported side effects
- Increased heart rate after a single dose (Jadoon 2017)
- With THC-containing products, increased heart rate and a drop in blood pressure on standing (Sultan 2018; Watanabe 2021: orthostatic hypotension RR 3.16)
Monitoring done in studies
- In people taking blood pressure medicine, monitoring of blood pressure and dizziness (with a doctor)
- In people using THC-containing products, monitoring of pulse and dizziness on standing; with a doctor in people with heart disease
Who should be careful
- For someone who takes blood pressure medicine or has low blood pressure, CBD may carry a risk of dizziness and a drop in blood pressure; this is a drug interaction issue, and a doctor should be consulted
- High doses and market doses cannot be compared: in low-dose (≤175 mg/day) studies, plasma levels were 5–100 times lower than with the 20 mg/kg Epidiolex dose (Warren 2026, PMID 42473010)
- Anyone taking long-term medicines should consult a doctor before starting; the studies on this page did not systematically assess interactions
- THC-containing products raise heart rate and can cause a drop in blood pressure on standing up (Sultan 2018, PMID 29385080; Watanabe 2021, PMID 33952424). This drop can resemble fainting: in a 1982 case report, within 10 minutes of smoking marijuana, the blood pressure of 3 glaucoma patients fell suddenly on standing, their pulse did not speed up, and the symptoms went away when they lay down (Merritt 1982, PMID 6283454). Marijuana shortened exercise time in angina (Aronow 1975, 10 patients, no placebo; PMID 1126112). Observational studies show a link with heart attack, stroke and atrial rhythm problems, but cause and effect has not been shown (Storck 2025, PMID 40527600; Chye 2026, PMID 40472951); extra care is needed in people with heart disease
- People who use cannabis regularly and are thinking of stopping, especially those with high blood pressure: in a small study in which 13 people who used cannabis daily were monitored in hospital, blood pressure rose when they stopped cannabis; in 6 people, the average increase reached up to 22.8 mmHg in systolic and 12.3 mmHg in diastolic blood pressure, and the authors recommended monitoring blood pressure during the stopping period (Vandrey 2011, PMID 21359104). In 39 people who stopped heavy use, however, no significant change in blood pressure or pulse was seen (Bonnet 2016, PMID 26761126). Both studies are small, and their results differ.
Drug interactions
- The studies on this page did not systematically assess drug interactions; details are in the site's drug interactions section
- Losartan: a CBD-dominant extract (which also contained 20 mg THC) increased losartan AUC by 77% (Bansal 2023, PMID 37313955)
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
- Do not replace your blood pressure medicine with CBD or cut back on it on your own.
- If you take blood pressure medicine, talk about CBD with your doctor; together you can keep track of your blood pressure and any dizziness.
- Because an interaction has been seen with medicines such as losartan, you can also review all the medicines you take with your pharmacist.
- If your blood pressure is low or you often feel dizzy, extra care is needed.
- Check the product label and certificate of analysis (COA).
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
There are small studies suggesting that CBD can lower blood pressure by a few points for a short time. However, this effect is small, disappeared quickly in one study, was not seen at all in some studies, and its long-term effect on heart health is unknown. Cannabis containing THC, on the other hand, raises heart rate; in most large population studies, it was linked to a higher risk of heart attack, stroke and heart rhythm problems, but studies of this kind do not show cause and effect. Continuing your blood pressure treatment together with your doctor is the safest path.
Frequently asked questions
Does CBD oil work for blood pressure?
In small studies, CBD lowered blood pressure by a few points; in people with high blood pressure, 24-hour systolic blood pressure was about 5 mmHg lower than with an inactive substance (placebo). However, the effect is small and short-lived; in healthy people it disappeared within a week in one study, and in some studies it was not seen at all (for example, with 100 mg a day for 12 weeks). This is not evidence of a treatment.
Can CBD replace blood pressure medicine?
No. There is no research showing that CBD keeps blood pressure under control over the long term or prevents heart attack and stroke. Do not stop or cut back on your blood pressure medicine on your own.
Can CBD be used together with blood pressure medicine?
It calls for caution. In people taking blood pressure medicine, CBD may carry a risk of dizziness and an excessive drop in blood pressure. In addition, in one study, a CBD-dominant extract that also contained THC increased the amount of losartan in the body by 77%. Make this decision together with your doctor.
Does CBD affect heart rate?
In a study of healthy men, a single dose of CBD raised heart rate; in other small studies, heart rate did not change compared with an inactive substance. In a study of people with high blood pressure, no new heart rhythm problems were seen. Cannabis containing THC, by contrast, clearly raises heart rate.
Can CBD oil be obtained with a prescription for blood pressure 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, can be sold only in pharmacies. Those classified as medicines and health products are dispensed with a prescription; the regulation does not state a prescription requirement for supplement products and cosmetics with a THC content of at most 0.3%. As of October 2026, there is no approved CBD medicine in Turkey. If you are thinking of using it, talk to your doctor first.
Is cannabis (marijuana) risky for the heart?
Cannabis containing THC raises heart rate and, in some people, can cause a drop in blood pressure on standing up and dizziness. In most large population studies, heart attack, stroke and heart rhythm problems were more common in people who used cannabis; some studies with long follow-up, however, found no link. These studies do not show cause and effect, but they call for caution in someone with heart disease. If you take heart or blood pressure medicine, talk to your doctor.
References
Show 39 references
- Jadoon 2017. Double-blind, crossover RCT. PMID 28614793, doi:10.1172/jci.insight.93760
- Sultan 2020. Double-blind, parallel RCT. PMID 32128848, doi:10.1111/bcp.14225
- Dragun 2023. Double-blind, crossover pilot RCT. PMID 37291376, doi:10.1007/s12325-023-02560-8
- Dujic 2024 (HYPER-H21-4). Triple-blind, crossover RCT. PMID 37093160, doi:10.1089/can.2022.0320, NCT05346562, protocol Kumric 2022, PMID 35887534, secondary publications from the same trial: Kumric 2023, PMID 36780785, Kumric 2023, PMID 37321059, Batinic 2023, PMID 37373421, Dujic 2025, PMID 39187263, Kumric 2025, PMID 41203237
- McNamara 2026 (ARCHER). Phase 2, multicenter, double-blind, placebo-controlled RCT. PMID 41711722, doi:10.1093/eschf/xvaf034, NCT05180240, June 17, 2026), design paper McNamara 2024, PMID 38937900
- Haney 2016. Double-blind, placebo-controlled, within-subject (crossover) laboratory RCT; multicenter. PMID 26708108, doi:10.1038/npp.2015.367, NCT01844687, secondary analysis of the same trial: Babalonis 2017, PMID 28088032
- Bell 2025. Randomized, crossover, placebo-controlled pilot study (triple-blind according to the registry; according to the article, all 12 people correctly guessed which day they took CBD). PMID 41515147, doi:10.3390/nu18010029, NCT06364254
- Mastrofini 2024. Double-blind, placebo-controlled, parallel RCT. PMID 38904150, doi:10.1080/15502783.2024.2370430
- Arout 2022. Double-blind, placebo-controlled, within-subject (crossover) outpatient laboratory study (PubMed publication type: RCT). PMID 34223660, doi:10.1111/bcp.14973
- Spindle 2020. Double-blind, double-dummy, placebo-controlled, within-subject (crossover) laboratory study; session order randomized. PMID 32247649, doi:10.1016/j.drugalcdep.2020.107937
- Luis 2026. Phase 2, open-label, multicenter (no control group). PMID 42432451, doi:10.1161/JAHA.125.047605, NCT05494788, October 20, 2025, in the registry, CRP normal at week 8 in 7 of 12 patients, in the article in 8 of 10 patients with high CRP), NCT06708299
- Sellers 2013 (QT study). Double-blind, placebo- and active drug (moxifloxacin)-controlled, four-arm parallel RCT (thorough QT study). PMID 27121791, doi:10.1002/cpdd.36, NCT01322139
- Mathew 2003. Randomized, double-blind, placebo-controlled laboratory study. PMID 12873621, doi:10.1016/s0091-3057(03)00086-8
- Laurentino 2026. Randomized, double-blind, placebo-controlled, crossover study. PMID 42660566, doi:10.1002/bcp.70793, Protocol: Fagundes 2025, PMID 41226928, the published analysis has three conditions), Brazilian registry RBR-3jsvtbr
- Cheung 2024. Controlled crossover laboratory study (randomized and single-blind according to the registry; each participant received all three conditions). PMID 39575727, doi:10.1161/JAHA.124.037731, NCT04693884, a second publication from the same trial: Cheung 2025, PMID 41115058
- Elias 2026 (MARY-JANE). Prospective, randomized crossover pragmatic trial (a daily text message instructing "use" or "don't use"; no blinding). PMID 42584385, doi:10.1016/j.jacc.2026.07.014, NCT06021613
- Rosa 2022 (SativexStroke). Secondary analysis of an RCT (double-blind, placebo-controlled, crossover); blood pressure and pulse were compared only between the first and last 5 days of the drug period (not with placebo; no comparison group); patients measured and recorded the values themselves every day. PMID 36386386, doi:10.3389/fcvm.2022.990188, Main trial: Marinelli 2022, PMID 35812088
- Crawford and Merritt 1979. Controlled clinical study (comparison with a placebo cigarette; randomization not in the abstract). PMID 468444
- Aronow 1975. Controlled comparison study (marijuana cigarette vs. high-nicotine tobacco cigarette; no placebo, randomization not in the abstract). PMID 1126112, doi:10.1002/cpt1975175549, The same group's study comparing marijuana with placebo marijuana: Aronow 1974, NEJM, PMID 4599385, full text could not be read), psychological outcomes in 10 angina patients with the same design: Gottschalk 1977, PMID 870096, hemodynamics in coronary disease: Prakash 1975, PMID 1097149
- Gonzalez 2026. Single-blind, placebo-controlled, fixed-order (placebo night first, then THC night) exploratory study; secondary analysis of a pilot study. PMID 42665978, doi:10.14814/phy2.71076, Sleep and heart rate variability in the same participants: Gonzalez 2026, PMID 41692699
- Roberts 2026. Systematic review (RCTs; numbers were not pooled because the studies differed). PMID 42321899, doi:10.1186/s42238-026-00463-3, A meta-analysis published in Brazil that the review cites (Candeloro 2025) could not be found in PubMed or Europe PMC
- Sultan 2017. Systematic review and meta-analysis (animal and human studies). PMID 28286481, doi:10.3389/fphar.2017.00081
- Sultan 2018. Systematic review and meta-analysis (animal and human studies). PMID 29385080, doi:10.3390/ph11010013, The PubMed title says "Δ8", the article's own title and text say Δ9-THC
- Watanabe 2021. Systematic review and meta-analysis (RCTs). PMID 33952424, doi:10.1016/j.japh.2021.03.013
- Storck 2025. Systematic review and meta-analysis (observational studies; risk of bias with ROBINS-E). PMID 40527600, doi:10.1136/heartjnl-2024-325429, PROSPERO CRD42023401401
- Sebastian 2025. Systematic review and meta-analysis (observational cohort data). PMID 39800612, doi:10.1016/j.disamonth.2024.101849, PROSPERO CRD42024530366
- Ravi 2018 (systematic review). Systematic review (observational studies; strength of evidence graded). PMID 29357394, doi:10.7326/M17-1548, PROSPERO CRD42016051297
- Chye 2026. Systematic review and meta-analysis (large population studies). PMID 40472951, doi:10.1016/j.hrthm.2025.05.062, PROSPERO CRD42023428219
- Ritson 2026. Systematic review and meta-analysis (observational studies) with genetic (Mendelian randomization) analysis. PMID 41566428, doi:10.1177/17474930261418926, PROSPERO CRD420251053702
- Abuhasira 2021. Prospective observational study (no comparison group; each patient compared with their own baseline). PMID 33483174, doi:10.1016/j.ejim.2021.01.005, 15-person subgroup of the same cohort: Abuhasira 2022, PMID 36294974, THC/CBD ratios of the products)
- Zongo 2021. Retrospective matched cohort (administrative health data and cannabis clinic records). PMID 34507536, doi:10.1186/s12872-021-02229-6, Heart failure in the same data source: Dubois 2026, PMID 41497552, 15:100120, 2014–2019 cohort)
- Holt 2024. Nationwide register-based matched cohort. PMID 38200679, doi:10.1093/eurheartj/ehad834
- Keyhani 2025. Prospective cohort (THC Cohort; adjusted with survey weights and propensity scores). PMID 40686207, doi:10.1161/CIRCULATIONAHA.124.073193
- Mittleman 2001. Case-crossover study (each patient compared with themselves); multicenter heart attack onset study (Determinants of MI Onset Study). PMID 11401936, doi:10.1161/01.cir.103.23.2805, Long-term follow-up of the same cohort: Frost 2013, PMID 23351819, first follow-up analysis Mukamal 2008, PMID 18294478
- Jeffers 2024. Population-based cross-sectional study (US BRFSS health survey, 2016–2020). PMID 38415581, doi:10.1161/JAHA.123.030178
- Corroon 2025 (CARDIA). Prospective cohort (CARDIA; weighted models for time-dependent factors). PMID 40785536, doi:10.1161/HYPERTENSIONAHA.125.25005, Cardiovascular events in the same cohort: Reis 2017, PMID 28207342
- Haleem 2021. Population-based prospective survey cohort (NESARC, two waves). PMID 33644920, doi:10.1111/dar.13266
- Falkstedt 2017. Population-based cohort (Swedish military conscription cohort, national registers). PMID 28028147, doi:10.1161/STROKEAHA.116.015565
- Teraoka 2024. Prospective cohort (UK Biobank). PMID 38142832, doi:10.1016/j.hrthm.2023.12.008
Points that could not be verified from the full text
- The 1974 study comparing marijuana cigarettes with placebo cigarettes in patients with angina (Aronow 1974, NEJM) and the hemodynamic study in coronary disease (Prakash 1975) have no abstracts; their full texts could not be read. The angina row in the table is based on the abstract of the same group's 1975 study
- Unpublished or ongoing studies (October 2026): a placebo-controlled phase 3 study of CBD in recurrent pericarditis (NCT06708299) is recruiting; an open-label phase 1 study of CBD in heart failure (NCT03634189, Mexico) has not been updated since 2020 and has no results; the phase 2/3 study with the same CBD medicine in 90 people hospitalized with COVID-19 who had cardiovascular disease or risk factors (NCT04615949), which was stopped early, has no peer-reviewed publication; its registry results are in the table; a blood pressure study with synthetic THC, NCT07231965, is not yet recruiting
- A 2025 meta-analysis on CBD and blood pressure (Candeloro 2025, a journal published in Brazil) is cited in a 2026 review; it could not be found in PubMed or Europe PMC and could not be read
- The full texts of Jadoon 2017, Sultan 2020, Dragun 2023, Dujic 2024, Haney 2016, Arout 2022, Sellers 2013, Mathew 2003, Laurentino 2026, Elias 2026, Crawford and Merritt 1979, Aronow 1975, Watanabe 2021, Storck 2025, Sebastian 2025, Chye 2026, Abuhasira 2021, Holt 2024, Mittleman 2001, Haleem 2021, Falkstedt 2017 and Teraoka 2024 are not open access or could not be read; these rows are based on abstracts, ClinicalTrials.gov records and other open-access publications of the same studies. For this reason, in the 70-person high blood pressure study (Dujic 2024), it could not be verified whether the 4.76 mmHg drop in blood pressure was compared with placebo or with baseline
Research history
Here we record what changed on this page, when and why, with dates. The newest change is at the top.
October 2026 additional review: sources found for this page during the searches for other topics were read and added to the page. A 1982 case report was added to the warning about a drop in blood pressure on standing with THC-containing products: after smoking marijuana, blood pressure fell suddenly in 3 glaucoma patients, the picture resembled fainting, and the symptoms went away when they lay down. The information that blood pressure fell in some people in a 1977 study in which THC was given into a vein was not added, because it could not be verified in the study's own abstract. In the warning about blood pressure rising when stopping cannabis, it was stated clearly that 22.8 and 12.3 mmHg are the amount of the increase, not the blood pressure itself. The conclusion and strength of evidence did not change.
Display fix: internal working notes left over from the previous cleanup were removed; content and evidence did not change.
Display fix: internal working file names left in the text were removed; content and evidence did not change.
Older changes (6)
Information on blood pressure when stopping cannabis use was added to the "Who should be careful" section: in a 13-person study of daily users, blood pressure rose in some of them after stopping (Vandrey 2011), and in another study of 39 people there was no change (Bonnet 2016). The conclusion and strength of evidence did not change.
In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were searched systematically; 33 studies were added: 5 RCTs with CBD in healthy volunteers (in four, blood pressure and heart rate were no different from placebo; in one, blood pressure fell slightly), 9 studies with THC-containing products (heart rate, a drop in blood pressure on standing, heart rhythm, blood vessel function, angina, stroke patients taking blood pressure medicine; 8 of them controlled), 9 systematic reviews and meta-analyses, and 10 observational studies examining cannabis use and medical cannabis in relation to heart attack, stroke, heart rhythm problems, heart failure and high blood pressure. In the existing rows, the product, dose, registry number and funding of the high blood pressure studies were added; it was noted that both studies were carried out by the same research group, with the same company's patented product and with that company's funding, and that in the larger one the abstract does not make clear whether the drop was compared with placebo or with baseline. For the myocarditis study, the registered primary outcome, the funding of the heart inflammation studies, the authors' company ties and the side effects were added. The conclusion for THC-containing products was written for the first time (strength of evidence: 'Insufficient'). For pure CBD, the conclusion and strength of evidence did not change.
Related studies: Haney 2016, published July 2016 (PMID 26708108, doi:10.1038/npp.2015.367, NCT01844687, secondary analysis of the same trial: Babalonis 2017, PMID 28088032); Bell 2025, published December 20, 2025 (PMID 41515147, doi:10.3390/nu18010029, NCT06364254); Mastrofini 2024, published December 2024 (PMID 38904150, doi:10.1080/15502783.2024.2370430); Sellers 2013 (QT study), published July 2013 (PMID 27121791, doi:10.1002/cpdd.36, NCT01322139); Mathew 2003, published May 2003 (PMID 12873621, doi:10.1016/s0091-3057(03)00086-8); Laurentino 2026, published August 27, 2026 (online) (PMID 42660566, doi:10.1002/bcp.70793, Protocol: Fagundes 2025, PMID 41226928, the published analysis has three conditions), Brazilian registry RBR-3jsvtbr); Cheung 2024, published December 3, 2024 (PMID 39575727, doi:10.1161/JAHA.124.037731, NCT04693884, a second publication from the same trial: Cheung 2025, PMID 41115058); Elias 2026 (MARY-JANE), published July 30, 2026 (online) (PMID 42584385, doi:10.1016/j.jacc.2026.07.014, NCT06021613); Rosa 2022 (SativexStroke), published October 28, 2022 (PMID 36386386, doi:10.3389/fcvm.2022.990188, Main trial: Marinelli 2022, PMID 35812088); Crawford and Merritt 1979, published May 1979 (PMID 468444); Aronow 1975, published May 1975 (PMID 1126112, doi:10.1002/cpt1975175549, The same group's study comparing marijuana with placebo marijuana: Aronow 1974, NEJM, PMID 4599385, full text could not be read), psychological outcomes in 10 angina patients with the same design: Gottschalk 1977, PMID 870096, hemodynamics in coronary disease: Prakash 1975, PMID 1097149); Gonzalez 2026, published September 2026 (PMID 42665978, doi:10.14814/phy2.71076, Sleep and heart rate variability in the same participants: Gonzalez 2026, PMID 41692699); Roberts 2026, published June 19, 2026 (PMID 42321899, doi:10.1186/s42238-026-00463-3, A meta-analysis published in Brazil that the review cites (Candeloro 2025) could not be found in PubMed or Europe PMC); Sultan 2017, published February 24, 2017 (PMID 28286481, doi:10.3389/fphar.2017.00081); Sultan 2018, published January 31, 2018 (PMID 29385080, doi:10.3390/ph11010013, The PubMed title says "Δ8", the article's own title and text say Δ9-THC); Watanabe 2021, published 2021 (PMID 33952424, doi:10.1016/j.japh.2021.03.013); Storck 2025, published October 29, 2025 (PMID 40527600, doi:10.1136/heartjnl-2024-325429, PROSPERO CRD42023401401); Sebastian 2025, published March 2025 (PMID 39800612, doi:10.1016/j.disamonth.2024.101849, PROSPERO CRD42024530366); Ravi 2018 (systematic review), published February 6, 2018 (PMID 29357394, doi:10.7326/M17-1548, PROSPERO CRD42016051297); Chye 2026, published May 2026 (PMID 40472951, doi:10.1016/j.hrthm.2025.05.062, PROSPERO CRD42023428219); Ritson 2026, published July 2026 (PMID 41566428, doi:10.1177/17474930261418926, PROSPERO CRD420251053702); Abuhasira 2021, published April 2021 (PMID 33483174, doi:10.1016/j.ejim.2021.01.005, 15-person subgroup of the same cohort: Abuhasira 2022, PMID 36294974, THC/CBD ratios of the products)); Zongo 2021, published September 10, 2021 (PMID 34507536, doi:10.1186/s12872-021-02229-6, Heart failure in the same data source: Dubois 2026, PMID 41497552, 15:100120, 2014–2019 cohort)); Holt 2024, published February 7, 2024 (PMID 38200679, doi:10.1093/eurheartj/ehad834); Keyhani 2025, published August 12, 2025 (PMID 40686207, doi:10.1161/CIRCULATIONAHA.124.073193); Mittleman 2001, published June 12, 2001 (PMID 11401936, doi:10.1161/01.cir.103.23.2805, Long-term follow-up of the same cohort: Frost 2013, PMID 23351819, first follow-up analysis Mukamal 2008, PMID 18294478); Jeffers 2024, published March 5, 2024 (PMID 38415581, doi:10.1161/JAHA.123.030178); Corroon 2025 (CARDIA), published October 2025 (PMID 40785536, doi:10.1161/HYPERTENSIONAHA.125.25005, Cardiovascular events in the same cohort: Reis 2017, PMID 28207342); Haleem 2021, published September 2021 (PMID 33644920, doi:10.1111/dar.13266); Falkstedt 2017, published February 2017 (PMID 28028147, doi:10.1161/STROKEAHA.116.015565); Teraoka 2024, published April 2024 (PMID 38142832, doi:10.1016/j.hrthm.2023.12.008); Arout 2022, published January 2022 (PMID 34223660, doi:10.1111/bcp.14973); Spindle 2020, published June 1, 2020 (PMID 32247649, doi:10.1016/j.drugalcdep.2020.107937)
The names of the finding labels were simplified: the label "Small benefit possible" on this page became "May help a little". The assessment did not change.
Newly published and previously missed clinical studies were searched in PubMed and ClinicalTrials.gov. 2 studies added: McNamara 2026 (ARCHER) and Luis 2026. The conclusion and strength of evidence did not change.
Related studies: McNamara 2026 (ARCHER), published February 3, 2026 (PMID 41711722, doi:10.1093/eschf/xvaf034, NCT05180240, June 17, 2026), design paper McNamara 2024, PMID 38937900); Luis 2026, published July 21, 2026 (PMID 42432451, doi:10.1161/JAHA.125.047605, NCT05494788, October 20, 2025, in the registry, CRP normal at week 8 in 7 of 12 patients, in the article in 8 of 10 patients with high CRP), NCT06708299)
The year of a publication named on the page was corrected to the journal's print year instead of its online publication year. The conclusion and strength of evidence did not change.
Page published. This first review examined 4 studies.