Hamm-Buiar and colleagues conducted a systematic review and network meta-analysis of 27 randomized controlled trials evaluating cannabinoids for MS-related spasticity.

The analysis included over 3,000 participants and examined multiple intervention types: THC:CBD extracts, other cannabis extracts, isolated cannabinoids (natural or synthetic), and smoked cannabis.

Searches covered PubMed, EMBASE, and LILACS through December 2025. Risk of bias was assessed using the RoB 2 tool, and evidence certainty was graded using GRADE and CINeMA.

In the pairwise meta-analysis of 7 studies, THC:CBD extracts reduced patient-reported spasticity compared to placebo with a mean difference of -0.82 on the assessment scale (95% CI -1.24 to -0.40).

The network meta-analysis confirmed the superiority of THC:CBD combinations. However, heterogeneity across studies was substantial (I² = 53%), suggesting that benefits varied considerably between trials.

Effects were modest in absolute terms. While statistically significant, the clinical meaning of a 0.82-point improvement depends on the scale used and individual patient values.

Adverse events were frequent across the trials but were mostly mild to moderate in severity. Serious adverse events were rare.

Common side effects included dizziness, drowsiness, dry mouth, and cognitive effects. The frequency and type of adverse events varied depending on the cannabinoid preparation and dose.

No unexpected safety signals emerged, but the evidence was not sufficient to define optimal dosing or identify which MS patients would tolerate cannabinoids best.

The certainty of evidence was graded as LOW using GRADE criteria. This reflects clinical and methodological heterogeneity across the included trials.

Variability in spasticity measurement tools, cannabinoid formulations, doses, and treatment durations made direct comparisons difficult. Patient populations differed in disease severity and prior treatments.

Most trials were small and sponsored by cannabinoid manufacturers, which raises questions about selection bias. Blinding and allocation concealment were not consistently reported.

The authors concluded that cannabinoids provide modest improvements in patient-reported spasticity in MS but should be considered cautiously as adjunctive therapy with appropriate safety monitoring.

THC:CBD extracts appear superior to other cannabinoid preparations, but the low evidence certainty and modest effect size do not support them as first-line therapy.

Better outcome measures (objective spasticity assessment, functional mobility, quality of life) and longer follow-up periods are needed to clarify the true clinical value of cannabinoids in MS spasticity.

MS-related spasticity affects up to 80 percent of people with MS and significantly impacts quality of life. Established treatments include physical therapy, baclofen, tizanidine, and botulinum toxin injections.

There is substantial patient interest in cannabis-based treatments for spasticity, partly due to limited efficacy or tolerability of conventional medications and to cultural narratives about cannabis benefits.

This systematic review provides the most current synthesis of evidence but confirms that cannabinoids should remain adjunctive, not replace established therapies, and should be used within a structured clinical framework.

I would interpret this review as confirming that cannabinoids have a modest place in MS care for select patients whose spasticity is inadequately controlled by conventional approaches.

The 0.82-point improvement is real and statistically significant but is not transformative. For some patients, even modest relief is valuable; for others, the side-effect burden may not justify the benefit.

The low evidence certainty reflects genuine methodological challenges in cannabis research—heterogeneous formulations, inconsistent dosing, and patient expectations all complicate the picture.

My clinical practice reflects this: I ask about spasticity impact, discuss realistic expectations, ensure conventional therapies are optimized, document the specific product and dose, and monitor for both benefit and adverse effects.

Four Steps to Interpret the Findings