Abstract
Hormonal reassignment has two aims: (1) to reduce the hormonally induced secondary sex characteristics of the original sex and (2) to induce the secondary sex characteristics of the new sex. In Europe, cyproterone acetate is generally used to inhibit androgens in male-to-female transsexuals. Medroxyprogesterone acetate is an acceptable, though less effective, alternative. To induce feminization there is a wide range of oestrogens. Oral ethinyloestradiol is a potent and inexpensive oestrogen, but it may cause venous thrombosis. Oral 17beta-oestradiol valerate or transdermal 17beta-oestradiol is the treatment of choice. The goal of treatment in female-to-male transsexuals is to induce virilization, including a male pattern of sexual hair, a male voice and male physical contours, and to stop menses. The principal hormonal treatment is a testosterone preparation. Hormone-dependent tumours have been encountered and surveillance is necessary.