Androgen suppression

Androgen suppression, also known as testosterone suppression, is a medical treatment to suppress or block the production or action of male sex hormones, typically used against certain cancers that rely on male growth hormones. This a done by castration (sometimes chemical castration) or by prescribing female sex hormones and drugs called antiandrogens. It is employed in androgen deprivation therapy for prostate cancer, feminizing hormone therapy for transgender women, PCOS, acne and hirsutism in women, and against other androgen-dependent conditions.

Role in gender affirming care

An important goal for many transgender women is to live in society as women, as secondary sex characteristics are vastly impacted by sex hormones, the modulation and suppression of certain sex hormones like testosterone and DHT are important to accomplish this goal. Further anti-androgenic effects can be caused by the suppression of hormones that trigger the release of androgens such as DHEA and gonadotropin-releasing hormone (GnRH). This can be achieved in a number of ways including hormone therapy and surgery.

Anti-androgen medication

Supplementation of estrogens, which is already a primary aspect of feminizing hormone therapy, has some anti-androgenic effects due to negative feedback on the hypothalamic–pituitary–gonadal axis. This is usually used in conjunction with specific anti-androgen medication for the sole purpose of androgen suppression as most patients require additional anti-androgen medication to decrease testosterone production. While all antiandrogens exist to suppress androgens, different antiandrogens have different mechanisms of action which may act on specific or multiple portions of the androgen metabolic pathway in order to either halt the production of androgens or block androgen receptors. Several subclasses of anti-androgen medication which are differentiated by mechanism of action include the following.