Centre for Reproductive Health

Horne group

 Endometriosis, chronic pelvic pain and ectopic pregnancy.

Professor Andrew W Horne (PhD, FRCOG, FRCP Edin, FRCSEd, FRSE, FMedSci)

Professor of Gynaecology and Reproductive Sciences

  • Director, Centre for Reproductive Health
  • Specialty Advisor to Scotland’s Chief Medical Officer for Obstetrics and Gynaecology
  • President-elect of the World Endometriosis Society & Co-Editor in chief of Reproduction and Fertility

Contact details



The Centre for Reproductive Health
Institute for Regeneration and Repair (IRR)
4-5 Little France Drive
Edinburgh BioQuarter

Post Code
EH16 4UU

Clinical matters

Please note that, due to NHS Lothian IT Security Policy, I am afraid that I am unable to respond to emails about clinical matters. If you would like me to contact you about a clinical matter, please email Fiona Elliot (my NHS secretary) on fiona.elliot@nhslothian.scot.nhs.uk and include your date of birth (or CHI number), phone number (and/or address), so that I can get back to you.

Main research area and why it is important

Professor Horne has a vision that ultimately all medical interventions for women with endometriosis will have an underlying evidence base, demonstrating that their action does more good than harm. In case of uncertainty, he believes that patients must be informed of the evidence gap, and optimally, be offered participation in a clinical trial.

To achieve this goal, he has established EXPPECT Edinburgh. EXPPECT brings together individuals involved in the clinical care of women with pelvic pain and endometriosis with discovery scientists to form a hub within which innovative approaches to pelvic pain treatment can be developed in collaboration with commercial partners.

With the support of the EXPPECT team, he is most proud of the work that he has carried out to further the understanding of the aetiology of endometriosis and develop a potential non-hormonal treatment for the condition.

His studies have shown that peritoneal mesothelial cells from women with endometriosis have an altered metabolic phenotype, similar to cancer cells. This finding has underpinned a body of work which has demonstrated that it is possible to treat women with endometriosis with a drug that has previously been tested in cancer and led to exploratory clinical trials in women. Taken together, his findings provide the rationale for targeting metabolic processes as a non-contraceptive treatment for women with endometriosis either as primary non-hormonal management or to prevent recurrence after surgery.

Infographic of Endometriosis Lesions

Endometriosis lesions contain a complex mixture of cells and represent a unique specialized microenvironment (Figure from Saunders & Horne, Cell 2021)

Current research projects

MAC-Endo: A proof-of-concept and feasibility study of macrophage-targeted immunotherapy in the management of endometriosis-associated pain

Horne AW (CI), Dhaun N, Greaves E, Moakes C, Durand H, Cox E


A randomised, double-blind, placebo-controlled feasibility trial to evaluate dichloroacetate in the management of endometriosis-associated pain (EPiC2)

Whitaker L (CI), Horne AW, Daniels J, Saraswat L, Jones MC, Graham C


ENDOCAN-1: a pilot randomised controlled trial of the efficacy of a cannabinoid oral tincture in the management of endometriosis-associated pain

Whitaker L (CI), Horne AW, Daniels J, Saraswat L, Lewis S, Durand H, Neilson A, Cox E


ENVISION: Endometriosis biomarker Study

AW Horne (CI), LHR Whitaker (co-CI), M Hund, A-M Olziersky, D Allegranza


ADVANTAGE visceral pain consortium: Advanced Discovery of Visceral Analgesics via Neuroimmune Targets and the Genetics of Extreme human phenotype

Woods G (CI), Horne AW, Lee M, Malliaris G, St John Smith E, Andersson D, Denk F, Williams A, Tsanas T, Saunders P


Deep infiltrating endometriosis: management by medical treatment versus early surgery: DIAMOND

Clark TJ (CI), Cooper K (co-CI), Bhattacharya S, Byrne D, Smith P, Horne AW, Amer S, Maclennan G, Scotland G, Murchie P, Gillies K, Gamaleldin I, Vashisht A, Cox E


ESPriT2: A multi-centre randomised controlled trial to determine the effectiveness of laparoscopic treatment of isolated superficial peritoneal endometriosis for the management of chronic pelvic pain in women

 Horne AW (CI), Whitaker L (co-CI), Norrie J, Daniels J, Stephens J, Cooper K, Clark TJ, Becker C, Cheong Y, Thornton J, Maheshwari A, Vincent K, Jackson L, Cox, E, Hummelshoj L, King K


Recurrence of Endometriosis: a randomised controlled trial of clinical and cost-effectiveness of Gonadotrophin Releasing Hormone Analogues with add-back hormone replacement therapy versus repeat Laparoscopic surgery (REGAL trial)

Saraswat L (CI), Cooper K, Bhattacharya S, Horne AW, Clark TJ, Becker C, Vyas S, Saridogan E, McLennan G, Scotland G, Gillies K, Jones G


Selected publications

Giudice LC, Horne AW, Missmer SA. Time for global health policy and research leaders to prioritize endometriosis. Nat Commun. 2023 14(1):8028.

Horne AW, Tong S, Moakes CA, Middleton LJ, Duncan WC, Mol BW, Whitaker LHR, Jurkovic D, Coomarasamy A, Nunes N, Holland T, Clarke F, Doust AM, Daniels JP, for the GEM3 collaborative. Combination of gefitinib and methotrexate to treat tubal ectopic pregnancy (GEM3): a multicentre, randomised, double-blind, placebo-controlled trial. Lancet 2023 (22)02478-3.

Horne AW, Missmer SA. Pathophysiology, diagnosis, and management of endometriosis. BMJ. 2022 379:e070750.

Saunders PTK, Horne AW. Endometriosis: etiology, pathobiology, and therapeutic prospects. Cell 2021 184(11):2807-2824.

Hogg C, Panir K, Dhami P, Rosser M, Mack M, Soong D, Pollard JW, Jenkins SJ, Horne AW, Greaves E. Macrophages inhibit and enhance endometriosis depending on their origin. Proc Natl Acad Sci USA 2021 118(6):e2013776118.

Horne AW, Vincent K, Hewitt CA, Middleton LJ, Koscielniak M, Szubert W, Doust AM, Daniels JP, on behalf of the GaPP2 collaborative. Gabapentin for chronic pelvic pain in women (GaPP2): a multicentre, randomised, double-blind, placebo-controlled trial. Lancet 2020 396(10255):909-917.

Horne AW, Saunders PTK. Endometriosis. Cell 2019 179(7):1677-1677e1.

Horne AW, Ahmad SF, Carter R, Simitsidellis I, Greaves E, Hogg C, Morton NM, Saunders PTK. Repurposing dichloroacetate for the treatment of women with endometriosis. Proc Natl Acad Sci USA 2019 116(51):25389-25391.

Horne AW, Vincent K, Cregg R, Daniels J. Is gabapentin effective for women with unexplained chronic pelvic pain? BMJ 2017 358:j3520.

Kvaskoff M, Horne AW, Missmer SA. Informing women with endometriosis about ovarian cancer risk. Lancet 2017 390(10111):2433-2434.

Horne AW, Saunders PTK, Abokhrais IM, Hogg L; Endometriosis Priority Setting Partnership Steering Group. Top ten endometriosis research priorities in the UK and Ireland. Lancet 2017 389(10085):2191-2192.

Young VJ, Brown JK, Maybin J, Saunders PT, Duncan WC, Horne AW. Transforming growth factor-β induced Warburg-like metabolic reprogramming may underpin the development of peritoneal endometriosis. J Clin Endocrinol Metab 2014 jc20141026.