Consecutive Cyproterone Acetate and Estradiol Treatment in Late-Pubertal Transgender Female Adolescents

The study retrospectively analyzed the effects of Cyproterone acetate (CA), an antiandrogenic progestin, alone and in combination with estrogens (E) on 27 late-pubertal transgender female adolescents. The participants were initially treated with CA monotherapy for an average of 12 months, followed by a combination of CA and incremental doses of estrogens for an average of 16 months. The treatment led to a decrease in facial and non-facial hair growth, with one-third of the participants experiencing breast development during CA monotherapy, which increased during the combined CA + E treatment. Side effects reported included breast tenderness, emotionality, fatigue, and flushes, but no significant weight changes were observed. Main safety parameters indicated a decrease in hemoglobin and hematocrit, a transient and modest increase in liver enzymes during CA, and slight changes in lipid levels. Gonadotropins decreased and testosterone levels dropped throughout the treatment, while prolactin levels increased with CA and normalized with CA + E. The study concluded that CA treatment was safe, well-tolerated, and induced mild feminizing effects, with rapid feminization following the addition of estrogens. However, the study's limitations included its modest sample size and retrospective nature.