What 2,544 MS Patients Tell Us About Cannabis and Spasticity
A new systematic review and meta-analysis in Clinical Therapeutics offers the most comprehensive look yet at cannabis for multiple sclerosis spasticity. The findings challenge short-term skepticism and point toward a treatment pattern that rewards patience.
Multiple sclerosis affects roughly one million Americans, and spasticity, the involuntary muscle stiffness and painful cramping that many MS patients live with daily, is among the most disabling features of the disease. Standard pharmaceutical options, baclofen, tizanidine, and dantrolene, carry a significant burden of side effects including sedation, weakness, and cognitive blunting. Nabiximols (Sativex), a cannabis-derived oromucosal spray, is approved for MS spasticity in over 25 countries but remains unavailable through the FDA in the United States.
This meta-analysis arrives at a moment when federal cannabis rescheduling has made research access easier and clinical conversations more comfortable. For the first time in decades, physicians in the United States can have frank, evidence-grounded discussions about cannabis for neurological symptoms without navigating quite the same federal headwinds. The evidence base this review synthesizes is now directly actionable in that context.
| Authors | AlHabil Y, Saadeddin L, Ishkirat H, et al. |
| Journal | Clinical Therapeutics, January 2026; 48(1):13-21 |
| Study Type | Systematic Review and Meta-Analysis of RCTs |
| Trials Included | 9 clinical trials (2003–2021, multi-country) |
| Patients | 2,544 MS patients |
| Interventions | Whole-plant extracts, oils, smoked cannabis (THC/CBD) |
| Primary Outcomes | Spasticity (Ashworth Scale, NRS, VAS) |
| Overall Effect | SMD 39.19 (95% CI: 34.32-44.05) — significant improvement |
| Long-term Effect | MD 75.81 (95% CI: 66.39-85.22) |
| Short-term Effect | MD 4.53 (95% CI: -0.06 to 9.12) — borderline |
| Adverse Events | Mild (dizziness, dry mouth); no serious events reported |
| PMID | 40753057 |
The research team searched the literature systematically and identified nine controlled trials enrolling 2,544 patients with MS across multiple countries. Studies spanned from 2003 to 2021, representing nearly two decades of clinical investigation. The cannabinoid interventions varied: some trials used whole-plant extracts, others tested standardized oils, and several included smoked cannabis. THC, CBD, or combinations of both were the active agents across the included studies. The primary outcome in each case was spasticity, measured using the Ashworth Scale, the Numeric Rating Scale, or visual analog scales depending on the study design.
The pooled analysis found a statistically significant and clinically meaningful improvement in spasticity across the group as a whole. The most striking finding was the separation between short-term and long-term outcomes. Brief treatment periods produced borderline results, a mean difference of 4.53 that barely cleared the threshold of significance. Extended treatment, by contrast, produced a mean difference of 75.81, a magnitude that represents a qualitative shift in symptom burden, not just a statistical footnote. Adverse events were consistent with what is seen in outpatient cannabis medicine: dizziness and dry mouth, both manageable and typically transient.
This is a systematic review and meta-analysis, the highest tier of synthesized clinical evidence. Nine randomized or controlled trials contributed data. The study carries real authority because it aggregates individual trial results rather than relying on any single experiment.
Important caveats: Heterogeneity was substantial (I² = 100% overall; 91% for NRS analyses), meaning the individual trials differed considerably in their populations, formulations, dosing, and outcome measures. Funnel plot asymmetry raised concern about publication bias. These limitations do not invalidate the findings, but they do mean the effect sizes should be interpreted as directional signals rather than precise predictions for any individual patient. The authors appropriately call for further trials with standardized protocols.
The finding that matters most here is not the overall effect size. It is the time-course. Short-term studies showed borderline results. Long-term studies showed a mean difference nearly twenty times larger. That gap tells you something important about how cannabis works in the context of a chronic neurological condition like MS.
We see this pattern in practice. Patients come in after a week or two and say they are not sure the cannabis is doing anything. They still have spasticity. Their muscles are still stiff in the morning. What they are missing is that they are comparing themselves to where they were two weeks ago, not to where conventional therapy left them six months ago. The endocannabinoid system is not like a beta blocker that drops your blood pressure within an hour. It is a regulatory system. It takes time to engage meaningfully. This meta-analysis puts numbers around what experienced clinicians have been observing for years.
The safety profile in this review is also worth noting. Across 2,544 patients and nine trials spanning two decades, the adverse events were dizziness and dry mouth. Not cognitive impairment. Not falls. Not dependency signals requiring the severity of reporting we see with baclofen titration or tizanidine-related hepatotoxicity. That does not mean cannabis is risk-free, and I always counsel patients in that direction. But it does mean the conversation about comparative safety deserves to happen with accurate data on both sides, not with reflexive caution about one option and uncritical acceptance of another.
In Massachusetts and across our patient population at CED Clinic, MS-related spasticity comes up frequently. Patients often arrive having tried standard antispasmodic medications and found them sedating, or they have been told there is nothing else to consider. This evidence says otherwise. The trajectory of benefit with cannabis in MS is not immediate, but it is real, and in a disease measured in decades, that distinction should inform how we set expectations rather than foreclose conversations prematurely.
Spasticity in MS: The Treatment Gap Cannabis May Help Fill
Between 60 and 80 percent of people with MS experience spasticity at some point in their disease course. The symptom exists on a spectrum: intermittent muscle cramping at the mild end, constant painful rigidity and functional impairment at the severe end. Standard pharmaceutical antispasmodics work through gamma-aminobutyric acid (GABA) pathways or direct muscle relaxation, mechanisms that carry dose-limiting side effects that many patients find as disabling as the spasticity itself.
Cannabis works differently. THC and CBD interact with CB1 and CB2 receptors distributed throughout the central nervous system, modulating neurotransmitter release, reducing excitatory tone in spinal circuits, and engaging anti-inflammatory pathways that conventional antispasmodics do not reach. This mechanistic distinction helps explain why cannabinoid-based medicines may produce benefit in patients for whom GABA-targeting drugs have failed, and it also explains why the effect takes time to accumulate rather than appearing within hours of the first dose.
For more on how cannabinoids modulate pain signals and their interaction with the nervous system, see our recent evidence review: Cannabinoids for Nerve Pain: What the Best Clinical Evidence Says About Sleep and Pain Relief.
The Long-Term Signal: Why Duration Changes Everything
The most clinically significant finding in this meta-analysis is the contrast between short-term and long-term treatment effects. Short-term studies produced a mean difference of 4.53, right at the edge of statistical significance. Long-term studies produced a mean difference of 75.81. That is not a modest improvement in effect size. It reflects a qualitative difference in what cannabis is doing over time in the nervous system of a person managing MS.
This finding has direct implications for clinical practice and patient counseling. Physicians who evaluate cannabis therapy in MS patients after two or four weeks may be looking too early. Patients who discontinue cannabis after a month because they do not feel dramatically different may be giving up before the trajectory of benefit has had the chance to develop. Managing that expectation, setting realistic timelines while emphasizing the importance of consistent dosing, is one of the more important clinical skills in cannabis medicine and one that this research now supports with quantified data.
The anti-inflammatory dimension of long-duration cannabinoid therapy may also contribute to this pattern. As we have discussed on this blog, preclinical work suggests that sustained cannabinoid exposure can modulate neuroinflammatory pathways beyond simple acute receptor activation: Cannabis Extract Shows Anti-Inflammatory and Antidepressant-Like Effects in Mice.
Heterogeneity and Publication Bias: Reading the Limitations Honestly
The authors are transparent about the methodological constraints. Heterogeneity across the nine included trials was extreme, with I² values of 100% for the overall analysis and for the Ashworth Scale subgroup, and 91% for the NRS subgroup. This means the individual studies varied substantially in their patient populations, cannabinoid formulations, dosing protocols, and outcome measurement approaches. Pooling them into a single estimate produces a signal that reflects the direction of effect but cannot be read as a precise, universally applicable number.
Publication bias is also flagged. Asymmetric funnel plots suggest that smaller negative trials may have gone unpublished, a common problem across all of clinical research but worth flagging explicitly here. The true effect of cannabis for MS spasticity may be somewhat smaller than the pooled estimates suggest. That said, the direction of the finding across nine independent trials, over two decades of research, and in over two thousand patients is consistent: cannabis-based therapies reduce spasticity in MS, and they do so more substantially when continued over time.
These are honest limitations from an honest research team. For a balanced view of the broader state of cannabis evidence, including where it is strong and where gaps remain, see: What We Know and What We Don’t About Marijuana’s Health Effects.
Cannabis for MS spasticity is not a new idea. Nabiximols (Sativex), a standardized 1:1 THC:CBD oromucosal spray, has been approved for MS spasticity in the United Kingdom, Canada, Germany, Australia, and over 20 other countries for well over a decade. The clinical rationale has existed for years. What has lagged is the integration of that evidence into U.S. clinical practice, partly because of regulatory barriers and partly because of the fragmented nature of the evidence base that this review now consolidates.
The April 2026 federal rescheduling of state-licensed medical cannabis to Schedule III does not change the evidence, but it does change the clinical conversation. It signals federal acknowledgment of medical utility, it reduces research barriers for future trials, and it allows physicians and patients to discuss cannabis options with less friction from the institutional context in which those conversations occur. Combined with a growing literature base like this meta-analysis, the argument for serious clinical consideration of cannabis in MS spasticity management is stronger now than at any prior point in U.S. medicine.
AlHabil Y, Saadeddin L, Ishkirat H, Alqam M, Hossoon O, Hameedi S, Yacoub H, Yasin D, Bahbah A, Oweidat M, Mosa H. Assessing the Role of Cannabis in Managing Spasticity in Multiple Sclerosis: A Systematic Review and Meta-Analysis. Clin Ther. 2026 Jan;48(1):13-21. doi: 10.1016/j.clinthera.2025.07.009. PMID: 40753057.
