Cannabis-Based Medicinal Products for Endometriosis: A 2-Year Prospective Analysis From the UK Medical Cannabis Registry

Endometriosis can cause persistent pelvic pain, sleep disturbance, and reduced quality of life despite conventional treatment. In this prospective registry study, patients prescribed cannabis-based medicinal products reported sustained improvements in pain, sleep, anxiety, and overall quality of life over two years, with adverse effects generally mild to moderate.

Background: Endometriosis affects up to 10% of biological females of reproductive age. Current treatment options are limited and often unsuitable for prolonged use. Cannabis-based medicinal products (CBMPs) have emerged as an alternative for pain management.

Aims: To analyse changes in patient-reported outcome measures (PrOMs), prescribed opioid burden, and the prevalence of adverse events (AEs) in patients prescribed CBMPs for endometriosis-associated pain.

Materials and methods: This was an observational analysis of prospectively collected data from the UK Medical Cannabis Registry. Biological females (≥ 18 years) with a primary diagnosis of endometriosis, enrolled ≥ 2 years prior to data extraction on 06/01/2025, were included. PrOMs and prescribed oral morphine equivalents (OME) were assessed between baseline and 1, 3, 6, 12, 18, and 24 months. Changes from baseline were assessed by repeated-measures ANOVA and Bonferroni-adjusted post hoc pairwise t-tests. p < 0.050 was considered statistically significant.

Results: One hundred and one patients were included. Improvements from baseline were observed in BPI Severity, BPI Interference, SF-MPQ-2 Total, Pain VAS, EQ-5D-5L Index, GAD-7, and SQS at all follow-ups (p < 0.001). Mean prescribed OME decreased from 19.9 ± 17.2 mg/day at baseline to 14.8 ± 15.9 mg/day at 24 months. Eighteen participants (17.8%) reported 165 AEs, of which 84 (50.9%) were mild. The most frequent were fatigue (n = 16; 15.8%), lethargy (n = 15; 14.9%), and headache (n = 13; 12.9%).

Conclusion: CBMP treatment was associated with sustained improvements in pain, health-related quality of life, sleep, and anxiety at 24 months, with a favourable AE profile. Randomised controlled trials are required to establish efficacy and safety.”

https://pubmed.ncbi.nlm.nih.gov/42576801

“Cannabis-based medicinal products (CBMPs) have emerged as an alternative for managing endometriosis-associated chronic pain.

CBMPs include phytocannabinoids such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), which interact with the endocannabinoid system through cannabinoid receptor type 1 (CB1) and type 2 (CB2).

Anandamide, an endogenous cannabinoid, binds to these receptors to modulate pain. THC is a partial agonist of CB1 and CB2, while CBD increases anandamide by inhibiting its breakdown.”

https://obgyn.onlinelibrary.wiley.com/doi/10.1111/ajo.70173