Masculinizing hormone therapy

Masculinizing hormone therapy is a form of transgender hormone therapy which develops male secondary sex characteristics and suppresses or minimizes female ones.^[1][2][3] It is used by trans men and transmasculine individuals as part of gender transition, to align their body with their gender identity. This can alleviate gender dysphoria, and help individuals be correctly perceived as their respective gender ("passing").

Masculinizing hormone therapy involves taking testosterone, the primary male sex hormone. This causes many of the same bodily changes seen in male puberty, including deeper vocal pitch, greater facial and body hair, heightened sex drive, muscle growth, fat redistribution, and enhanced size and sensitivity of the clitoris ("bottom growth").^[4][5] It stops menstruation, and reduces production of estrogen, the primary female sex hormone. It cannot reverse breast development, which may necessitate chest reconstruction ("top surgery").

Other medications used include GnRH agonists and antagonists to completely suppress estrogen and progesterone; progestins like medroxyprogesterone acetate to suppress menstruation; and 5α-reductase inhibitors to prevent pattern hair loss. Sometimes another androgen instead of testosterone may be used.

Similar hormone regimens may also be used by intersex people to conform to their assigned sex, starting either in childhood, or during puberty.