CBD is not approved by the FDA to treat pain. No large trial shows CBD alone reduces chronic pain. Research on cannabis that contains THC shows a small effect on chronic pain. CBD-only research is smaller and shorter.
What the research says
Evidence for CBD by itself is thin. Most pain studies use cannabis with both THC and CBD. Trials with THC report a drop in pain scores of about half a point on a 10-point scale. A Cochrane review of cannabis-based medicines for chronic neuropathic pain rated the evidence as low quality.
CBD Pain Management: How It Helps and What to Know
Placebo response runs high in pain trials. In some studies, people who took a placebo reported relief close to the treatment group. That fact makes small studies hard to read. A 29-person case series on topical CBD for peripheral neuropathy reported less pain over 4 weeks. It had no control group.
Federal law allows hemp CBD with less than 0.3% THC on a dry weight basis. The FDA has approved one CBD drug, Epidiolex, for two forms of epilepsy. No approved CBD product carries a pain claim.
Forms of CBD
- Topical: creams, balms, patches. Applied to skin. Small amounts reach the blood.
- Oil or tincture: held under the tongue for 60 to 90 seconds. Absorption varies by person and product.
- Capsule or edible: passes through the liver. Onset takes 1 to 2 hours. Effects last longer than inhaled forms.
- Vape: fast onset. Carries lung risk. Not advised.
Doses in studies
No standard dose exists for pain. Published trials used 5 mg to more than 1,000 mg per day. Product labels and trial protocols do not match. A 30 mg bottle may hold 1,500 mg of total CBD. Read the total mg per bottle, not the mg per drop claim on the front panel.
Start with a low dose. Hold other drugs constant. Write down dose, time, and pain score in a log for 2 weeks. Stop if side effects appear.
Side effects and drug interactions
Common side effects: diarrhea, tiredness, sleepiness, and appetite change. High doses can raise liver enzymes. The Epidiolex label calls for liver monitoring in patients who take it.
CBD blocks several liver enzymes, including CYP3A4, CYP2C19, and CYP2D6. That block can raise blood levels of other drugs. Drugs of concern: warfarin, clobazam, tacrolimus, and some antidepressants. Ask a pharmacist before you mix CBD with a prescription drug.
What to check on a label
- A third-party lab report with a batch number
- THC content listed in mg
- Total cannabinoids per bottle
- A test date within 12 months
Bottom line
Evidence for CBD for pain is weak. Some people report relief. Others report none. The placebo effect in pain trials is real and large. CBD does not replace care from a clinician. For chronic pain, ask about treatments with stronger evidence first.