Whitaker, Lucy H.R.Middleton, Lee J.Daniels, Jane P.Williams, Alistair R.W.Priest, LeeOdedra, SmitaCheed, VershaStubbs, Clive E.Clark, T. JustinLumsden, Mary-AnnHapangama, Dharani K.Bhattacharya, SiladityaSmith, Paul P.Nicholls, Elaine P.Roberts, NeilSemple, Scott I.Saraswat, LuckyWalker, JaneChodankar, Rohan R.Critchley, Hilary O.D.2023-05-232023-05-232023-06-01Whitaker, L H R, Middleton, L J, Daniels, J P, Williams, A R W, Priest, L, Odedra, S, Cheed, V, Stubbs, C E, Clark, T J, Lumsden, M-A, Hapangama, D K, Bhattacharya, S, Smith, P P, Nicholls, E P, Roberts, N, Semple, S I, Saraswat, L, Walker, J, Chodankar, R R & Critchley, H O D 2023, 'Ulipristal acetate versus levonorgestrel-releasing intrauterine system for heavy menstrual bleeding (UCON) : a randomised controlled phase III trial', EClinicalMedicine, vol. 60, 101995. https://doi.org/10.1016/j.eclinm.2023.1019952589-5370RIS: urn:9891C79BBBF760CDB7680F460FDC5EBAhttps://hdl.handle.net/2164/20762Acknowledgments This project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership (grant 12/206/52). Medical Research Council (MRC) Centre grants to the Centre for Reproductive Health (CRH) (G1002033 and MR/N022556/1) are also gratefully acknowledged. The views expressed in this publication are those of the authors and not necessarily those of the Medical Research Council, National Institute for Health Research, or Department of Health and Social Care. We thank our Collaborative Group (listed in the Supplementary Material) for their contribution to recruitment, randomisation and collection of data, and to our Trial Steering and Data Monitoring Committees (members listed in Supplementary Material).13616366engHeavy menstrual bleedingUlipristal acetateSelective progesterone receptor modulatorLevonorgestrel-releasing intrauterine systemRandomised controlled trialFibroidLeiomyomaAdenomyosis endometriumUterusQuality of lifeAmenorrhoeaUltrasoundProgesterone receptor modulator associated endometrial changesDrug induced liver injuryUrgent safety measuresR MedicineMedical Research Council (MRC)12/206/52G1002033MR/N022556/1Supplementary DataRJournal article10.1016/j.eclinm.2023.10199560