A UK registry study of 63 endometriosis patients found medical cannabis improved pain scores, quality of life, anxiety, and sleep quality across 18 months, with about a quarter of patients experiencing mostly mild side effects.
Women with endometriosis, gynecologists, pain specialists, and anyone interested in medical cannabis for chronic pelvic pain.
What the researchers found
Cannabis-based medicinal products were associated with significant improvements in all pain-specific measures from baseline to 18 months (p<.050). Quality of life (EQ-5D-5L) improved at all timepoints (p<.050). Anxiety and sleep quality also improved (p<.050). Clinically significant improvements: 11-37% minimal, 5-22% moderate, 0-11% substantial. Adverse events in 25.4% (16 patients), 62 events total.
Why it matters
Endometriosis affects 1 in 10 women and causes chronic pain that is often inadequately treated. This provides the first longitudinal evidence that medical cannabis may improve multiple dimensions of endometriosis burden — pain, quality of life, anxiety, and sleep.
The numbers in context
63 patients. 18-month follow-up. All pain PrOMs improved (p<.050). EQ-5D-5L improved at all timepoints. GAD-7 and SQS improved. BPI/VAS: 11-37% minimally significant, 5-22% moderate, 0-11% substantial improvements. 62 AEs in 16 patients (25.4%).
How the study worked
Case series from the UK Medical Cannabis Registry. 63 patients with endometriosis-associated chronic pain prescribed CBMPs. Patient-reported outcomes (BPI, VAS, EQ-5D-5L, GAD-7, SQS) collected at baseline, 1, 3, 6, 12, and 18 months. Repeated measures ANOVA assessed changes.
What this study cannot tell us
No control group — improvements could be natural fluctuation or placebo. Small sample. Self-selected patients in a registry (survivorship bias). UK-specific regulatory context. Cannot determine which specific CBMP formulations are most effective.
How to read the evidence
Registry case series without control group — provides encouraging longitudinal data but cannot establish causation.
When this study was published
Published in 2026, the first longitudinal study of medical cannabis specifically for endometriosis pain.
The bigger picture
Endometriosis is chronically undertreated, and existing options (hormonal therapy, surgery) don't work for everyone. Medical cannabis could fill an important gap, especially given the multi-symptom improvement (pain, anxiety, sleep) that addresses the holistic burden of the disease.
Questions still open
- Would a randomized controlled trial confirm these improvements? Which endometriosis patients respond best to medical cannabis? Can medical cannabis reduce the need for surgical intervention?
Common questions
Can medical cannabis help with endometriosis pain?
What side effects did endometriosis patients experience?
Read the original research
A Longitudinal Assessment of Endometriosis Patients Prescribed Cannabis-Based Medicinal Products: A Case Series From the UK Medical Cannabis Registry.
The Australian & New Zealand journal of obstetrics & gynaecology, 66(1), e70078
Citation
Getter, Sara; Erridge, Simon; Warner-Levy, John; 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). A Longitudinal Assessment of Endometriosis Patients Prescribed Cannabis-Based Medicinal Products: A Case Series From the UK Medical Cannabis Registry.. The Australian & New Zealand journal of obstetrics & gynaecology, 66(1), e70078. https://doi.org/10.1111/ajo.70078
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