ENDOCAN-1: A study to see if CBD (cannabinoid) can help with endometriosis-related pain
| ISRCTN | ISRCTN13210908 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN13210908 |
| Integrated Research Application System (IRAS) | 1010848 |
| Protocol serial number | AC24037 |
| Sponsor | University of Edinburgh and NHS Lothian |
| Funder | Chief Scientist Office, Scottish Government Health and Social Care Directorate |
- Submission date
- 07/08/2025
- Registration date
- 03/03/2026
- Last edited
- 03/03/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Urological and Genital Diseases
Plain English summary of protocol
Background and study aims
This study, funded by the Chief Scientist Office (CSO) will use a solution called MRX-1 which is a cannabinoid solution that does not contain THC which we will use to see if it reduces pain in patients with endometriosis. Endometriosis is a condition that affects 1 in 10 women or those assigned female at birth and causes pain, infertility and can reduce quality of life. At the moment available drug treatments have unacceptable side effects and are often hormonal and are contraceptive. There is an unmet need to find new treatments . Cannabinoids have been shown to be effective in other pain conditions.
Who can participate?
We will recruit 100 women over a period of 18 months from NHS Lothian and NHS Grampian.
What does the study involve?
This study will involve 5 hospital visits over a period of 17-18 weeks. Once eligibility has been confirmed the participant will be selected by chance (randomised) to have either the trial solution or placebo solution. The solution will be dosed according to the participant's weight and the dose can be increased weekly up to a maximum of 6.25mg/kg twice daily. They will take the solution for a 12 week period. We will collect questionnaires to assess pain scores and quality of life information. This study will help us develop a larger multi centre study. We will also ask participants in Edinburgh to wear a smartwatch during their participation (optional).
What are the possible benefits and risks of participating?
Participants may or may not benefit from taking part in this trial, however the results from this trial might help to improve the healthcare of patients with endometriosis in the future. Participants may also feel some improvement in their pain symptoms.
The patient might experience some side effects caused by the study solution. If they experience intolerable side effects they can either reduce the dose they are taking or stop.
Questionnaires where possible can be completed online at home to reduce the time burden on patients.
The participants will have blood samples taken which might cause discomfort and bruising but this will be taken by a trained member of the research team.
Where is the study run from?
University of Edinburgh (UK)
When is the study starting and how long is it expected to run for?
April 2026 to March 2028
Who is funding the study?
Chief Scientist Office, Scottish Government Health and Social Care Directorate (UK)
Who is the main contact?
ETMT@ed.ac.uk
Contact information
Public
Centre for Reproductive Health, IRR, 4-5 Little France Road
Edinburgh
EH164UU
United Kingdom
| ETMT@ed.ac.uk |
Principal investigator, Scientific
4-5 Little France Drive
Edinburgh
EH16 4UU
United Kingdom
| Phone | +44 131 651 8321 |
|---|---|
| lucy.whitaker@ed.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Interventional double blind randomized parallel group placebo controlled trial |
| Secondary study design | Randomised parallel trial |
| Scientific title | ENDOCAN-1: A feasibility randomised controlled trial of the efficacy of a cannabinoid oral solution in the management of endometriosis-associated pain |
| Study acronym | ENDOCAN-1 |
| Study objectives | Primary objective: To determine the eligibility, recruitment and retention rates Secondary objectives: 1. To estimate the effectiveness of CBD solution to alleviate pain in women with endometriosis 2. To estimate the effectiveness of CBD solution to improve quality of life 3. To assess safety of CBD solution 4. To estimate the impact of CBD solution on analgesic use 5. To estimate compliance with treatment over a 12 week period 6. To estimate patient satisfaction with treatment 7. To estimate acceptability of proposed trial 8. To estimate cost implications of CBD treatment 9. To determine if there is a change to inflammatory markers expression Tertiary objective: To determine whether objective data collected via smartwatch correlates with patient reported outcomes |
| Ethics approval(s) |
Approved 20/02/2026, - (2 Redman Place, Stratford, London, E20 1JQ, United Kingdom; -; a@a), ref: - |
| Health condition(s) or problem(s) studied | Endometriosis |
| Intervention | Participants will be randomised into one of two treatment arms, via an online randomisation tool. CBD arm: participants in the active arm will be given oral CBD solution for 12 weeks duration. The starting dose will be a solution of 0.5 mg/kg BID administered morning and evening and taken with food. The dose will be increased if there is ongoing pain and tolerable or no side effects, as per below: Week Dose (mg/kg b.i.d) 1 0.5 2 1 3 2 4 3.25 5 4.75 6 6.25 A maximum dose of 6.25 mg/kg BID will be permitted. At Week 6, participants will attend a research visit for re-supply. After 12 weeks of treatment, a follow up visit will be carried out 10 days after end of treatment. Placebo arm: Identical dosing regime as above for 12 weeks. |
| Intervention type | Drug |
| Phase | Phase II |
| Drug / device / biological / vaccine name(s) | MRX1 [Cannabidiol] |
| Primary outcome measure(s) |
Proportion of those eligible who are consented and recruited (screening logs) from first screening, the proportion who are eligible and randomised after the screening period and those randomised who are retained (completing the 12 week outcome measures) after 12 weeks |
| Key secondary outcome measure(s) |
Measured at weeks 1-13: |
| Completion date | 31/03/2028 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 100 Years |
| Sex | Female |
| Target sample size at registration | 100 |
| Key inclusion criteria | 1. Women or assigned female at birth 2. Aged 18 years or over 3. Endometriosis identified at laparoscopy or imaging, performed within the last ten years 4. Self reported pelvic pain for more than six months 5. Weekly worst pain score of at least four on a numerical rating scale (NRS) on two or more occasions over the four weeks prior to randomisation 6. Willing not to take additional cannabinoids during the trial period 7. Willing to use effective contraception throughout the trial (if needed) 8. Willing and able to give informed consent 9. Willing to be contacted by text message |
| Key exclusion criteria | 1. Pregnant, breastfeeding or actively trying to get pregnant 2. Post-menopausal (no periods for >12 months and not taking hormonal treatments to prevent periods, or bilateral oophorectomy performed) 3. Suicidal thoughts or severe depression within the past year 4. Current use (or within the last 1 month) of other cannabinoid or cannabis products, determined by urine dipstick test 5. Chronic alcohol abuse 6. History of severe liver disease (Alanine transaminase (ALT) and/or aspartate aminotransferase (AST) more than 3-times the upper limit of normal (ULN)) and bilirubin greater than 2 times the ULN, Or moderate to severe hepatic impairment (Child-Pugh class B or C) 7. Concomitant use of Sodium Valproate, Clobazam, Stiripentol, Everolimus 8. Hypersensitivity to any of the components of the formulation as defined in the IB 9. Taking part in another CTIMP or interventional non-CTIMP study |
| Date of first enrolment | 01/04/2026 |
| Date of final enrolment | 30/09/2027 |
Locations
Countries of recruitment
- United Kingdom
- Scotland
Study participating centres
Old Dalkeith Road
Edinburgh
EH16 4SA
Scotland
Aberdeen
AB25 2ZN
Scotland
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| IPD sharing plan |
Editorial Notes
08/08/2025: Trial's existence confirmed by NHS HRA.
