Ann Intern Med

Chronic neuropathic pain: Cannabinoids with equivalent or higher THC-to-CBD ratios may be linked to small improvements

December 24, 2025

Cannabinoid products with high (or comparably equivalent) THC-to-CBD ratios may be associated with small improvements in chronic pain (primarily neuropathic pain)—while increasing risks for adverse events such as dizziness, nausea, and sedation. Trials were short-term (1-6 months); product variation and lack of clarity around product details were cited as limitations. This updated systematic review included 25 short-term (1-6 months) randomized, placebo-controlled trials in 2303 patients, 64% of whom had neuropathic pain. Products were categorized by THC-to-CBD ratio, synthetic vs. extract source, and method of administration.

• High THC-to-CBD ratio (oral, synthetic/purified): May reduce pain severity slightly (pooled difference, −0.78 points on a 0-10 scale), with associated risks for dizziness, nausea, or sedation. For THC-only products, while nabilone moderately reduced pain severity (pooled difference, −1.59 points), dronabinol did not (pooled difference, −0.23 points).
• Comparably equivalent THC-to-CBD ratio (oral/mucosal, extracts): Probably reduces pain severity slightly (pooled difference, −0.54 points), with associated risks for dizziness, nausea, or sedation.
• Low THC-to-CBD ratio: May not improve chronic pain, yet low-ratio mixed THC/CBD products may pose risks for dizziness, nausea, or sedation. CBD-only products may not be associated with increased risks of these harms.

Source:

Chou R, et al. (2025, December 23). Ann Intern Med. Cannabis-Based Products for Chronic Pain : An Updated Systematic Review. https://pubmed.ncbi.nlm.nih.gov/41429020/