CBD for Pain After Surgery: Randomized Trials

The days after surgery can be hard, with pain, sleepless nights and the side effects of painkillers. That is why people often ask, "Will CBD ease my pain, and will I need fewer painkillers?" In this article, we gathered the studies done to answer this question into a single table, and explained in plain language how CBD was used in the studies and what to keep in mind around the time of surgery. Detailed table: Pain After Surgery and CBD.

Why are people curious about CBD?

The strong painkillers (opioids) often used for pain after surgery can cause side effects such as sleepiness, nausea and constipation. So both patients and researchers are interested in options that could ease pain while also reducing the need for these medicines. CBD (cannabidiol), a compound found in cannabis that does not make you high or cloud your thinking, became one of the candidates.

A "randomized trial," as in the title, is a study in which patients are assigned to groups by chance: one group gets CBD, the other gets an inactive medicine (placebo) that looks the same. Well-designed studies like these are the most reliable way to show whether a product really works.

What does the research say?

Most of the studies below used pure CBD; the root canal study tested a CBD-rich cannabis extract.

In three controlled studies in healthy volunteers with experimentally induced pain, CBD also did not reduce pain; in one, pain perception was slightly higher than with placebo (Schneider 2022; Dieterle 2022; Arout 2022).

Why do the results differ somewhat? The studies were done in different surgeries, with different products and by different routes: some by mouth, some as a tablet absorbed through the cheek, some applied to the skin. The doses also varied widely. So it would not be right to generalize the result of a single study to every surgery; looked at together, the picture is clearer.

Analyses that combined studies: In an analysis that combined studies of cannabinoids (cannabis compounds and similar medicines) for pain after surgery, these products, most of which contained THC, made no difference in opioid use or pain at 24 hours; pain at 12 hours was slightly higher and drops in blood pressure were more common (Abdallah 2020). A more recent review could not calculate a combined result because the studies were so different from one another, and found the evidence conflicting (González Cárdenas 2025).

On our site's scale, the strength of evidence for pure CBD is weak, and the result so far is no benefit seen. Research is ongoing: there are registered studies testing CBD (in some, together with a small amount of THC) after knee replacement and shoulder arthroscopy; their results have not been published yet.

Possible side effects and drug interactions

• Liver: In patients with knee osteoarthritis who took high-dose CBD together with acetaminophen (paracetamol), which is often used after surgery, raised liver values were seen more often than with placebo (Pramhas 2023).
• Sleepiness: Drowsiness and dizziness increase with opioids, gabapentin or pregabalin, sedatives and alcohol.
• Blood thinners: There are no human data showing that pure CBD directly increases bleeding; but increases in the blood clotting value (INR) have been reported with warfarin, and the effect of clopidogrel may be reduced.
• Blood pressure: A single dose of CBD lowered blood pressure slightly (Arout 2022); with products containing THC, drops in blood pressure after surgery were more common (Abdallah 2020).

For interactions with the medicines you take: drug interaction checker.

How was it used in studies?

The doses below only show how the studies were done (study doses; not a personal recommendation).

• Kidney stone surgery (Narang 2023): 20 mg per day of an approved CBD medicine.
• Shoulder surgery (Alaia 2022): a tablet absorbed through the cheek, 25 or 50 mg 3 times a day depending on body weight (75–150 mg per day in total).
• Low back pain in the emergency department (Bebee 2021): a single dose of 400 mg.
• Knee replacement (Haffar 2022): CBD applied around the knee 3 times a day.
• Emergency dental pain (Chrepa 2024): a single dose of 10 or 20 mg per kilogram of body weight; a very high dose.
• Healthy volunteers: single doses between 200 mg and 1600 mg.

In other words, a wide range was tested, from small doses to very high ones; most studies did not see a clear benefit.

If you are thinking about using CBD

• For pain after surgery, use the pain treatment planned by your surgeon and anesthesia team; if your pain is not under control, tell them. Pain treatment can often be adjusted to your needs.
• If you use CBD or a cannabis product, be sure to say so before surgery: CBD before surgery: what to tell your anesthesia team?
• At your appointment, you can ask: Can CBD be used together with the painkillers I take? Should my liver tests be monitored while I take acetaminophen (paracetamol)? What should I do if I take a blood thinner?

In Turkey: Cannabis-derived products, including CBD, may be sold only in pharmacies (Law No. 7557 and the regulation dated January 31, 2026). Those classed as medicines or health products are dispensed with a prescription; the regulation does not state a prescription requirement for supplement products with a THC content of no more than 0.3%. As of October 2026, there is no approved (licensed) CBD medicine in Turkey. More: CBD regulations in Turkey.

Conclusion

CBD for pain after surgery has been tested in a few well-designed studies, and in most of them it was not clearly different from placebo; the need for painkillers did not go down either. Results from new studies are awaited. Until then, the most reliable path is the pain treatment planned by your surgeon and anesthesia team, and openly sharing every product you use with them.

Frequently asked questions

References