Effect of anti-androgens on body composition in transgender people: secondary analysis of a randomized clinical trial

Abstract

Background: Transgender people desiring feminization commonly use cyproterone acetate or spironolactone, but the optimal anti-androgen to achieve feminization of body composition is unclear. Aims: To assess the effect of anti-androgens on body composition. We hypothesized cyproterone acetate would result in a greater increase in body fat than spironolactone due to greater suppression of serum testosterone concentration and more potent androgen receptor antagonism. Methods: Secondary analysis of a randomized clinical trial of transgender people aged 18+ years newly commencing estradiol and randomized to spironolactone 100 mg daily or cyproterone acetate 12.5 mg daily for six months. Pre-speci..