Cyproterone acetate or spironolactone in lowering testosterone concentrations for transgender individuals receiving oestradiol therapy

Abstract

Background: Oestradiol with or without an anti-androgen (cyproterone acetate or spironolactone) is commonly prescribed in transfeminine individuals who have not had orchidectomy; however, there is no evidence to guide optimal treatment choice. Objective: We aimed to compare add-on cyproterone acetate versus spironolactone in lowering endogenous testosterone concentrations in transfeminine individuals. Design: Retrospective cross-sectional study. Methods: We analysed 114 transfeminine individuals who had been on oestradiol therapy for >6 months in two gender clinics in Melbourne, Australia. Total testosterone concentrations were compared between three groups; oestradiol alone (n = 21), oestra..