The short answer
No cannabis product is FDA-approved to treat arthritis. Reviews of cannabis for chronic pain rate the evidence as low to moderate quality. Cannabis may ease pain for some people. It does not slow joint damage or change the course of rheumatoid arthritis.
Medical Cannabis for Arthritis Dosage: A Practical Guide
What arthritis is
Arthritis covers more than 100 conditions. Osteoarthritis comes from cartilage wear at the joint. Rheumatoid arthritis is an autoimmune disease that attacks the joint lining. The CDC reports that about 1 in 4 US adults has a diagnosis of arthritis.
How cannabinoids act
THC binds CB1 receptors in the brain and CB2 receptors in immune tissue. CBD binds both receptors at low affinity. CBD also inhibits liver enzymes in the CYP450 family, including CYP3A4 and CYP2C19.
Does Medical Cannabis Help Arthritis?
CB2 receptors sit on immune cells. That is the basis for lab work on CBD and inflammation. Lab results do not carry over to humans at typical doses.
does medical cannabis help arthritis
What studies show
- A 2018 Cochrane review of cannabis-based medicines for chronic neuropathic pain found low to moderate quality evidence. Most trials ran under 3 months.
- Trials of smoked cannabis in pain used THC doses that cause impairment. Participants in those trials were not blind to treatment.
- Trials of topical CBD in knee osteoarthritis are small and lack a placebo group. Pain scores fell in those trials. The design limits what the results mean.
- No trial has shown that cannabis reduces joint damage on imaging.
Federal and state rules
The 2018 Farm Bill sets the federal THC limit for hemp at 0.3% on a dry weight basis. Medical cannabis programs run under state law. States differ on qualifying conditions, product forms, possession limits, and testing rules. Chronic pain qualifies in some states. Arthritis as a listed condition varies by state.
Risks and drug interactions
THC causes impairment, dizziness, dry mouth, and fast heart rate. A share of users develop dependence. CBD can raise liver enzymes. CBD raises blood levels of warfarin and clobazam and affects some anti-seizure drugs.
Arthritis treatment often includes methotrexate, NSAIDs, and biologics. Tell a pharmacist about every cannabis product you use, including topicals. Bring the product label with the cannabinoid content.
Dosing and product checks
No standard dose exists for arthritis. Published trials used ranges from a few milligrams to hundreds of milligrams of CBD per day. Start at a low dose and track pain scores and side effects in a log.
Ask for a certificate of analysis from an accredited lab. The report should list cannabinoid content, pesticides, heavy metals, residual solvents, and microbials. Hemp CBD labels have missed the stated content in testing studies.
Questions for a clinician
- Does my arthritis type change the risk profile?
- Will cannabis interact with my current drugs?
- What dose and route should I try first?
- Which side effects mean I should stop?