How Much Cannabis for Nerve Pain Relief: Doses and Timing

There is no single dose of cannabis for nerve pain. Amounts that produced pain relief in clinical trials range from about 1 mg to 30 mg of THC per dose, taken one to three times a day. CBD amounts in nerve pain studies range from 5 mg to 50 mg per day. Health Canada and most clinical guides say to start at 1 mg THC or less and raise the amount in small steps over days.

What the evidence shows

The 2018 Cochrane review pooled 16 trials of cannabinoids for chronic neuropathic pain, with 1,750 participants. About 1 in 6 people reported at least 30% pain relief. The number needed to treat was 6, which means six people treated for one to get that level of relief. The review rated evidence quality as low to moderate.

Doses used in trials

Nabiximols, a 1:1 THC to CBD oral spray: 2.5 mg THC per spray. Trials started at 1 spray per day and moved to 8 to 12 sprays per day, or 20 mg to 32.4 mg THC.
Nabilone: 0.25 mg to 1 mg, twice a day.
Dronabinol: 2.5 mg to 10 mg per day.
Inhaled flower at 10% THC: 1 to 3 inhalations, about 1 mg to 3 mg THC.
CBD isolate: 5 mg to 50 mg per day in most pain studies. Doses of 200 mg to 1,500 mg per day come from epilepsy trials, not nerve pain trials.

THC to CBD ratio

A 1:1 ratio is the most studied for nerve pain. Some people use CBD with little or no THC. CBD can change how the body breaks down THC, which raises blood THC levels.

how much cannabis for nerve pain relief

Onset and timing

Inhaled: onset in 1 to 10 minutes, peak at 15 to 30 minutes, effects last 1 to 3 hours.
Oral: onset in 30 to 90 minutes, peak at 2 to 4 hours, effects last 4 to 12 hours.

Do not take a second oral dose for at least 2 hours. Waits prevent stacking.

Raising the dose

Start at 1 mg THC or less.
Raise by 1 mg THC every 1 to 2 days.
Stop raising when pain drops or side effects appear.
Hold at that level and note the result.

Side effects that set the ceiling: drowsiness, dizziness, fast heart rate, anxiety, dry mouth, poor balance.

Higher doses

Some people need 20 mg to 30 mg THC per dose. Above that range, side effects rise and pain relief does not. THC has a biphasic effect, which means a high dose can make pain worse in some people.

What is unknown

Most trials ran 12 weeks or less. Long-term data is thin. Cannabis has not been shown to repair nerve damage. Common causes of nerve pain include diabetic neuropathy, chemotherapy, spinal injury, and shingles.

Safety notes

The FDA has not approved any cannabis product for nerve pain. Approved cannabis-related drugs cover other conditions: Epidiolex for seizures, and dronabinol and nabilone for nausea. Cannabis can interact with warfarin, clobazam, and valproate. Do not drive after use. Avoid cannabis with pregnancy, a history of psychosis, or heart disease. State law controls purchase and possession. A clinician can review dose and drug interactions.