Nearly 500 fibromyalgia patients in the UK saw improvements in pain, anxiety, and sleep after starting medical cannabis
A registry study of 497 fibromyalgia patients found that cannabis-based medicinal products were associated with improvements in pain, anxiety, sleep, and quality of life over up to 18 months, though adverse events were common.
Quick Facts
What This Study Found
All patient-reported outcome measures improved significantly from baseline through 18 months of follow-up. Higher daily CBD doses (above 25 mg) and previous cannabis experience were linked to better fibromyalgia-specific outcomes. However, 45.67% of patients reported adverse events, mostly mild-to-moderate, with fatigue being the most common.
Key Numbers
497 patients; mean age 44.66 years; 68.61% female; 53.92% unemployed; CBD doses above 25 mg/day associated with better outcomes (p < 0.050); 45.67% reported adverse events; 2,100 total AEs; 85.33% mild-to-moderate; fatigue most common AE (30.78%)
How They Did This
Case series from the UK Medical Cannabis Registry (UKMCR) analyzing 497 patients prescribed cannabis-based medicinal products for fibromyalgia. Outcomes measured at 1, 3, 6, 12, and 18 months using validated scales for symptom severity, widespread pain, quality of life, anxiety, and sleep.
Why This Research Matters
Fibromyalgia is notoriously difficult to treat, with many patients finding conventional therapies inadequate. This is one of the largest real-world datasets on medical cannabis for fibromyalgia, providing evidence that may inform clinical decisions.
The Bigger Picture
This adds to growing real-world evidence from medical cannabis registries worldwide. The high adverse event rate compared to other UKMCR patient groups may reflect fibromyalgia-specific sensitivity, possibly related to the central sensitization that characterizes the condition.
What This Study Doesn't Tell Us
No control group or randomization. Registry-based data subject to selection bias. Patients self-selected for treatment. High dropout rates likely at later follow-up points. Cannot distinguish cannabis effects from placebo or natural disease fluctuation.
Questions This Raises
- ?Why do fibromyalgia patients report more adverse events than other medical cannabis users?
- ?Does the central sensitization mechanism make these patients more sensitive to cannabinoid side effects?
- ?Would randomized controlled trials confirm these observational findings?
Trust & Context
- Key Stat:
- 497 fibromyalgia patients showed improvement across all outcome measures over 18 months
- Evidence Grade:
- Moderate: large real-world sample with validated outcome measures and extended follow-up, but no control group and observational design.
- Study Age:
- 2026 publication from the UK Medical Cannabis Registry.
- Original Title:
- UK Medical Cannabis Registry: a case series analysing clinical outcomes of medicinal cannabis therapy for fibromyalgia.
- Published In:
- Clinical rheumatology, 45(3), 1927-1938 (2026)
- Authors:
- Varadpande, Madhur(3), Erridge, Simon(22), Aggarwal, Arushika(3), Clarke, Evonne, McLachlan, Katy, Coomber, Ross, Barnes, Shelley, Darweish Medniuk, Alia, Guru, Rahul, Holden, Wendy, Sajad, Mohammed, Searle, Robert, Usmani, Azfer, Varma, Sanjay, Rucker, James J, Platt, Michael, Sodergren, Mikael H
- Database ID:
- RTHC-08682
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
What symptoms improved with medical cannabis for fibromyalgia?
Patients showed statistically significant improvements in fibromyalgia symptom severity, widespread pain, general quality of life, anxiety, and sleep quality.
Were there common side effects?
Yes, 45.67% of patients reported adverse events, totaling 2,100 events. Most (85.33%) were mild-to-moderate, with fatigue being the most common at 30.78%.
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Cite This Study
https://rethinkthc.com/research/RTHC-08682APA
Varadpande, Madhur; Erridge, Simon; Aggarwal, Arushika; Clarke, Evonne; McLachlan, Katy; Coomber, Ross; Barnes, Shelley; Darweish Medniuk, Alia; Guru, Rahul; Holden, Wendy; Sajad, Mohammed; Searle, Robert; Usmani, Azfer; Varma, Sanjay; Rucker, James J; Platt, Michael; Sodergren, Mikael H. (2026). UK Medical Cannabis Registry: a case series analysing clinical outcomes of medicinal cannabis therapy for fibromyalgia.. Clinical rheumatology, 45(3), 1927-1938. https://doi.org/10.1007/s10067-025-07846-6
MLA
Varadpande, Madhur, et al. "UK Medical Cannabis Registry: a case series analysing clinical outcomes of medicinal cannabis therapy for fibromyalgia.." Clinical rheumatology, 2026. https://doi.org/10.1007/s10067-025-07846-6
RethinkTHC
RethinkTHC Research Database. "UK Medical Cannabis Registry: a case series analysing clinic..." RTHC-08682. Retrieved from https://rethinkthc.com/research/varadpande-2026-uk-medical-cannabis-registry
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.