Cannabis & Multiple Sclerosis Spasticity
Published: British Journal of Clinical Pharmacology, August 2026
Researchers: Hamm-Buiar, Gorski et al. — Federal University of Paraná, Brazil — systematic review and network meta-analysis of 27 RCTs, 3,000+ participants
1. What Was Studied?
Multiple sclerosis (MS) is a neurological condition affecting the brain and spinal cord. One of the most common and debilitating symptoms is spasticity — muscle stiffness, involuntary muscle contractions, and painful spasms that affect up to 80% of people with MS and significantly limit daily life.
This systematic review and network meta-analysis — the most rigorous type of evidence synthesis available — pulled together all available randomized controlled trials testing cannabinoids for MS-related spasticity, covering more than 3,000 participants. Researchers searched the global literature through December 2025 and compared different cannabinoid formulations against each other and against placebo.
2. What Did They Find?
THC/CBD combined extracts showed a modest but statistically significant reduction in patient-reported spasticity compared to placebo — a mean difference of 0.82 points on a numerical rating scale
This effect was confirmed in both the direct pairwise meta-analysis and the network meta-analysis
Other cannabinoid formulations — including isolated cannabinoids and smoked cannabis — showed less consistent effects
Adverse events were frequent but mostly mild to moderate
Importantly, improvements were found in patient-reported spasticity scores but were less evident on objective clinical measures of muscle tone
The researchers rated the certainty of evidence as low due to significant heterogeneity between studies
3. What This Means
This is one of the most robust evidence reviews on cannabis and MS published to date — 27 trials and 3,000 people is a meaningful dataset. The consistent finding that THC/CBD combinations outperform other formulations for patient-reported spasticity adds important nuance to the conversation.
The gap between what patients report (improvement in spasticity) and what clinicians can objectively measure (muscle tone on examination) is a recurring theme in cannabinoid research and in MS specifically. Both are real — they just measure different things.
For people with MS dealing with spasticity that isn't well controlled by other medications, this review provides the strongest evidence yet that a THC/CBD combination is worth a conversation with a neurologist.
4. What This Does NOT Mean
The effect size is modest — a 0.82-point reduction on a 10-point scale is real but not large
Low certainty of evidence means these findings should be interpreted cautiously
Cannabinoids are not recommended as first-line treatment for MS spasticity — they are adjunctive options
Adverse events were common — dizziness, fatigue, and cognitive effects were frequently reported
Results apply specifically to spasticity, not to other MS symptoms, progression, or neurological function
5. Bottom Line
The most comprehensive evidence review of cannabis for MS spasticity to date found THC/CBD combinations produce modest, consistent improvements in patient-reported spasticity — though the certainty of evidence remains low and effects on objective clinical measures were less clear.
