Short answer
Cannabis is not an anti-inflammatory drug. No cannabis product holds FDA approval to treat inflammation. Lab and animal studies show that cannabinoids can lower cytokine levels and immune cell activity. Human trials are small, short, and mixed. A 2006 trial of nabiximols in rheumatoid arthritis found less pain and lower disease activity scores in 58 patients over 5 weeks. Other human data stay thin.
What the cannabinoids do
THC
Tetrahydrocannabinol binds CB1 receptors in the brain and CB2 receptors on immune cells. CB2 activation in animal models reduces release of TNF-alpha and IL-6. THC also causes impairment, tachycardia, and a rise in psychosis risk at high doses.
CBD
Cannabidiol binds CB1 and CB2 with low affinity. It acts as a negative allosteric modulator at CB1 and blocks the enzymes CYP3A4 and CYP2C19. Those enzyme effects change blood levels of warfarin, clobazam, and tacrolimus.
CBD for Inflammation Treatment: A Comprehensive Guide
Human evidence by condition
- Rheumatoid arthritis: one 5-week trial, 58 patients, nabiximols oromucosal spray. Pain on movement dropped. DAS28 scores dropped. The trial was small and industry funded.
- Inflammatory bowel disease: small trials of CBD-rich extract, mixed results, no large trial.
- Skin: topical CBD trials for acne and eczema hold fewer than 100 participants in total.
- Chronic pain: reviews report modest effects, with benefit seen in neuropathic pain, not inflammatory pain.
Doses used in research
Oral CBD trials use 200 mg to 1500 mg per day. Epidiolex dosing starts at 5 mg/kg per day and reaches 20 mg/kg per day for seizures. Nabiximols delivers 2.7 mg THC and 2.5 mg CBD per spray, with a cap of 12 sprays per day. Store shelves carry CBD bottles labeled 10 mg to 50 mg per serving. No dose is established for inflammation.
Risks
- Liver: 1500 mg per day of CBD raised liver enzymes in trials. Risk rises with alcohol, valproate, and existing liver disease.
- Interactions: CYP3A4 and CYP2C19 inhibition changes levels of blood thinners, seizure drugs, and transplant drugs.
- THC: impaired driving, memory problems, and dependence in about 1 in 10 adult users.
- Legal: cannabis is Schedule I under federal law. State rules differ.
- Vaping: vitamin E acetate in black market vapes caused EVALI, with 2807 hospitalizations in 2019.
Questions for a clinician
- Does my condition respond to standard anti-inflammatory drugs first?
- Does CBD interfere with my current prescriptions?
- What liver and drug level monitoring do I need?