Cannabis trial for endometriosis pain failed because participants could not stop driving
A three-armed RCT comparing inhaled THC + CBD oil, CBD oil alone, and placebo for endometriosis pain recruited only 12 of 63 intended participants, with most dropping out due to driving restrictions.
Quick Facts
What This Study Found
Only 12 of 63 target participants enrolled; 7 withdrew and only 4 completed; the primary barrier was the requirement to abstain from driving during THC treatment; high withdrawal rate made efficacy assessment impossible.
Key Numbers
12 of 63 target enrolled; 7 withdrew; 4 completed; 1 lost to follow-up; 10 adverse events (8 possibly cannabis-related); 2 serious adverse events (unrelated).
How They Did This
Three-armed RCT in Australia comparing inhaled THC (16%) flower + CBD oil (100mg/mL), CBD oil alone, or placebo oil; aimed for 63 participants; assessed safety, acceptability, and feasibility.
Why This Research Matters
Despite strong patient interest in cannabis for endometriosis, practical barriers like driving restrictions make clinical trials nearly impossible, leaving a major evidence gap.
The Bigger Picture
The tension between cannabis clinical research and real-world constraints represents a systemic barrier to generating the evidence base that patients and clinicians need.
What This Study Doesn't Tell Us
Failed to achieve recruitment target; cannot assess efficacy; Australian regulatory context; small enrolled sample prevents meaningful safety conclusions.
Questions This Raises
- ?Can future trials use designs that accommodate driving needs?
- ?Would evening-only dosing or CBD-only arms improve recruitment?
- ?How can cannabis research overcome practical barriers?
Trust & Context
- Key Stat:
- Only 4 of 63 target participants completed the trial due to driving restrictions
- Evidence Grade:
- Feasibility RCT that failed its primary goal; valuable as a cautionary report for future trial design.
- Study Age:
- Published 2025
- Original Title:
- Challenges in conducting a feasibility randomized controlled trial of medicinal cannabis for endometriosis pain in Australia.
- Published In:
- Complementary therapies in clinical practice, 61, 102023 (2025)
- Authors:
- Chesterman, Susan, Mikocka-Walus, Antonina(2), Sinclair, Justin(14), Druitt, Marilla, Furyk, Jeremy, Evans, Subhadra, Abbott, Jason, Eathorne, Alexandra, Martin, Alexander, Ng, Cecilia, Nguyen, Lisa, Oldfield, Karen, Romano, Daniel, Sarris, Jerome, Semprini, Alex, Stanley, Katherine, Armour, Mike
- Database ID:
- RTHC-06208
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Why did the trial fail?
The main barrier was the requirement to abstain from driving while using THC-containing cannabis. Most participants could not comply with this restriction in their daily lives.
Is there evidence cannabis helps endometriosis?
People with endometriosis commonly report using cannabis for symptoms, but this trial failure means controlled clinical evidence remains absent.
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Cite This Study
https://rethinkthc.com/research/RTHC-06208APA
Chesterman, Susan; Mikocka-Walus, Antonina; Sinclair, Justin; Druitt, Marilla; Furyk, Jeremy; Evans, Subhadra; Abbott, Jason; Eathorne, Alexandra; Martin, Alexander; Ng, Cecilia; Nguyen, Lisa; Oldfield, Karen; Romano, Daniel; Sarris, Jerome; Semprini, Alex; Stanley, Katherine; Armour, Mike. (2025). Challenges in conducting a feasibility randomized controlled trial of medicinal cannabis for endometriosis pain in Australia.. Complementary therapies in clinical practice, 61, 102023. https://doi.org/10.1016/j.ctcp.2025.102023
MLA
Chesterman, Susan, et al. "Challenges in conducting a feasibility randomized controlled trial of medicinal cannabis for endometriosis pain in Australia.." Complementary therapies in clinical practice, 2025. https://doi.org/10.1016/j.ctcp.2025.102023
RethinkTHC
RethinkTHC Research Database. "Challenges in conducting a feasibility randomized controlled..." RTHC-06208. Retrieved from https://rethinkthc.com/research/chesterman-2025-challenges-in-conducting-a
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.