FRIDAY, Jan. 2, 2026 (HealthDay News) -- Short-term treatment with comparable and high tetrahydrocannabinol (THC)-to-cannabidiol (CBD) ratio cannabinoid products may improve pain and increase common adverse events, according to a review published online Dec. 23 in the Annals of Internal Medicine.
Roger Chou, M.D., from the Oregon Health & Science University in Portland, and colleagues conducted a systematic review to update the evidence on cannabinoids for chronic pain. Cannabinoids were classified by THC-to-CBD ratio (high, comparable, or low), source, and administration method. Cannabinoids were assessed in 25 short-term (one to six months) randomized controlled trials, with 2,303 participants.
The researchers found that pain severity may be reduced slightly with oral synthetic/purified high THC-to-CBD (THC only) and oromucosal, extracted, comparable THC-to-CBD ratio products (pooled differences, −0.78 and −0.54 points, respectively); moderate-to-large increases were seen in dizziness, sedation, and nausea. Nabilone moderately reduced pain severity but dronabinol did not, among THC-only products (pooled differences, −1.59 and −0.23 points, respectively). Outcomes may not be improved by low THC-to-CBD interventions. CBD alone may not increase harms, while low THC-to-CBD mixed THC/CBD products may increase dizziness, sedation, and nausea.
"CBD-based products are widely available in dispensaries. Many people use these products and they think it helps," Chou said in a statement. "Our goal is to provide some scientific basis to help people make their decisions."