A Systematic Review of Antiandrogens and Feminization in Transgender Women

The systematic review evaluated the efficacy of various antiandrogens in achieving feminization in transgender women, including spironolactone, cyproterone acetate (CPA), bicalutamide, GnRH analogues, and 5α-reductase inhibitors. It found significant methodological variability among the four included studies, making meta-analysis unfeasible. While CPA, GnRH analogues, and MPA were more effective than spironolactone in suppressing serum total testosterone, there was no significant difference in body composition changes between CPA and GnRH analogues. The review noted a lack of robust comparisons for breast development and facial/body hair reduction among different antiandrogens and questioned the reliance on serum total testosterone as a marker for feminization. It concluded that more high-quality, prospective randomized controlled studies with clinically relevant endpoints are needed to optimize antiandrogen therapy in transgender women.