Endometriosis affects approximately 1.5 million women in the UK — roughly 1 in 10 of reproductive age. Diagnosis takes an average of 8 years, and treatment options have been limited to hormonal therapies, pain management, and surgery. A new wave of clinical trials is bringing targeted hormonal treatments, GnRH antagonists, non-hormonal approaches, and improved surgical techniques to UK patients.
UK endometriosis research is coordinated through the NIHR and NHS England Endometriosis Centres. All Party Parliamentary Groups have pushed for increased research funding. Major centres include UCLH, Oxford, Birmingham, and specialist endometriosis centres across the UK. The first new oral treatments in decades are now entering late-stage UK trials.
There are currently over 20 actively recruiting endometriosis trials in the UK, spanning medical and surgical approaches.
Types of Endometriosis Trials
Hormonal Therapy
GnRH antagonists (elagolix, linzagolix, relugolix) offering endometriosis pain relief with fewer side effects than older hormonal treatments.
Non-Hormonal
Novel anti-inflammatory, anti-angiogenic, and immune-modulating treatments targeting endometriosis lesions directly.
Surgical
Advanced laparoscopic techniques for deep endometriosis, nerve-sparing surgery, and fertility-preserving approaches.
Fertility
IVF protocols for endometriosis-associated infertility, surgical vs medical management, and ovarian reserve preservation.
GnRH Antagonist & Hormonal Trials
Elagolix — oral GnRH antagonist showing significant pain reduction in endometriosis. UK trials testing: long-term safety, low-dose regimens, and add-back therapy to prevent bone loss
Linzagolix — once-daily oral GnRH antagonist with dose-dependent oestradiol suppression. UK Phase 3 trials for endometriosis-associated pain
Relugolix combination — relugolix + oestradiol/norethindrone (add-back therapy) to provide pain relief while minimising hypoestrogenic side effects. UK trials ongoing
Dienogest optimisation — the progestin dienogest (Visanne) is used widely for endometriosis. UK trials comparing: different doses, cyclic vs continuous, and combination with other agents
New progestins — next-generation progestational agents with improved side effect profiles, in UK Phase 2 trials
Non-Hormonal & Novel Approaches
Anti-angiogenic therapy — targeting the blood vessel formation that supports endometriosis lesion growth, with UK trials testing oral anti-angiogenic agents
Immune modulation — drugs targeting the inflammatory immune response that drives endometriosis pain and progression, including anti-IL-6 and anti-TNF approaches
P2X3 receptor antagonists — novel pain targets blocking the nerve signalling pathway specific to chronic pelvic pain, in UK Phase 2 trials
Epigenetic therapies — targeting the epigenetic changes that promote endometriosis lesion survival, in UK early-phase trials
Botulinum toxin — Botox injections into pelvic floor muscles for endometriosis-associated pelvic floor spasm and pain, in UK trials
Surgical & Fertility Trials
Deep endometriosis surgery — nerve-sparing surgical techniques for deep infiltrating endometriosis affecting the bowel, bladder, and ureter. UK trials comparing: shaving vs segmental resection vs disc excision
Robotic surgery — robot-assisted laparoscopic surgery for complex endometriosis, with UK trials evaluating: operative precision, recovery time, and fertility outcomes
IVF for endometriosis — optimising IVF protocols for women with endometriosis-associated infertility, including: surgical pretreatment timing, ovarian stimulation protocols, and embryo transfer strategies
Ovarian reserve preservation — trials of ovarian tissue cryopreservation and AMH-guided surgical planning to protect fertility in women undergoing endometriosis surgery
Adhesion prevention — barrier agents and anti-adhesion strategies to reduce post-surgical adhesions, a major cause of ongoing pain and infertility
Who Can Participate?
Medical therapy trials — confirmed or suspected endometriosis, moderate to severe pain (most trials require VAS pain score ≥4), premenopausal, not pregnant or breastfeeding
GnRH antagonist trials — regular menstrual cycles, adequate bone mineral density (DEXA scan may be required), not on concurrent hormonal therapy
Surgical trials — confirmed endometriosis requiring surgery, deep endometriosis (for deep excision trials), suitable for laparoscopic surgery
Fertility trials — endometriosis-associated infertility, attempting conception, adequate ovarian reserve (AMH >1 ng/mL for most trials)
General criteria — age 18-45 (most trials), BMI 18-35, no other significant pelvic pathology, not on long-acting hormonal contraception (for most medical trials)
UK Endometriosis Trial Locations
London — UCLH Endometriosis Centre, Guy's and St Thomas', Imperial College Healthcare
Oxford — John Radcliffe Hospital (Oxford Endometriosis Centre)
Endometriosis trial eligibility often requires documented pain scores and treatment history. Keep a pain diary (0-10 scale) for at least one menstrual cycle before approaching a trial. Record: daily pain, menstrual patterns, medication use, and impact on daily activities. Also keep records of any laparoscopies, imaging, and hormonal treatments you've tried — most trials require confirmed diagnosis and documented failure of at least one prior treatment.
How to Find Your Match
Use our Smart Matcher to find endometriosis trials tailored to your specific situation. Whether you are newly diagnosed, exploring targeted therapy, or seeking advanced treatment options, we can match you to actively recruiting studies.