Optimal feminizing hormone treatment in transgender people

Transgender women are assigned male at birth but identified as w omen. The incidence of gender dysphoria is estimated to be around 1% of the population. Gender dysphoria m ay be associated with depression and low quality of life, which in most cases improves during gender-affirming hor monal treatment (GAHT). Feminizing hormonal treatment for transgender women or gender non-binary people typ ically includes natural estrogen (estradiol). Additional testosterone-blocking treatment is often needed to e nsure the suppression of the pituitary-gonadal axis and may include cyproterone acetate, a gonadotropin-releasing h ormone agonist (GnRH-a), or spironolactone. The health risks of cyproterone acetate as anti-androgen treatment are debated and randomized protocols with other anti-androgen treatments are requested. Orchiectomy is performed in some transgender women after various duration of GAHT. Currently, natural progesterone is not recommended as par t of GAHT due to limited knowledge on the balance between risks and benefits. In the present article, we discuss e vidence regarding established and upcoming feminizing treatment for adult transgender women or gender non-binary peop le seeking feminization. Data on study populations with transgender women are put into a wider context of literatu re regarding the effects of sex steroid hormones in cisgender study populations. Relevant follow-up and monitoring during feminizing treatment is debated. The review has a special focus on the pharmacotherapy of feminizing hormon al therapy.