Does cannabis help muscle spasms?
Cannabis has the most evidence for spasticity in multiple sclerosis (MS). A 2017 review by the National Academies of Sciences, Engineering, and Medicine found substantial evidence that oral cannabinoids reduce MS spasticity. The 2014 American Academy of Neurology guideline found oral cannabis extract and THC probably reduce patient-reported spasticity in MS. Evidence for other causes of muscle spasm is thin. No cannabis product is FDA-approved for muscle spasms. Epidiolex, a CBD drug, is approved for two epilepsy syndromes, not spasm.
Best CBD Products for Muscle Spasms: Reviews and Comparison
Spasticity is not the same as a spasm
A spasm is a sudden involuntary muscle contraction. Spasticity is a speed-dependent rise in muscle tone. Most trials measure spasticity, not spasms. That limits what the data say about cramps from exercise, dehydration, or nerve injury.
Medical Cannabis Dosage for Muscle Spasms
What the trials cover
Multiple sclerosis
Trials used nabiximols (Sativex), an oral spray with THC and CBD in near-equal amounts. Canada and several European countries approve it. The FDA does not. In trials, nabiximols lowered patient-reported spasticity scores. Objective tone measures changed less.
best cannabis strain for muscle spasms
Spinal cord injury and other causes
Studies are smaller. Results are mixed. The AAN found insufficient evidence for cannabis in spasticity from spinal cord injury or other causes.
CBD versus THC
CBD does not cause intoxication. THC does. Most positive spasticity trials used THC, often with CBD. Isolated CBD has little trial data for spasticity. Hemp-derived CBD products sold online must contain 0.3% THC or less under federal law. State rules differ.
Dose
There is no standard dose of cannabis or CBD for muscle spasms. Nabiximols trials started at one spray per day and raised the dose over weeks. Epidiolex starts at 2.5 mg/kg twice daily for seizures. That dose does not apply to spasm. Labels list CBD and THC in milligrams. Start low and record effect and side effects.
Risks
- Drowsiness, dizziness, dry mouth.
- Impaired driving and balance.
- CBD can raise levels of some drugs, including clobazam and warfarin.
- THC can cause anxiety and a fast heart rate.
- Smoked cannabis irritates the lungs.
Legal status in the US
Cannabis is Schedule I under federal law. Hemp, defined as cannabis with 0.3% THC or less, is legal under the 2018 Farm Bill. Some states ban or restrict CBD. Check state law before you buy.
Questions for a clinician
- Is my symptom spasticity or a spasm?
- What does the evidence say for my condition?
- Could cannabis interact with my prescriptions?