Hormone replacement therapy (female-to-male)

Hormone replacement therapy (HRT) of the female-to-male (FTM) type is a form of hormone therapy and sex reassignment therapy that is used to change the secondary sexual characteristics of transgender and transsexual people from feminine (or androgynous) to masculine. It is one of two types of HRT for transgender and transsexual people (the other being male-to-female), and is predominantly used to treat transgender men. Some intersex people also receive this form of HRT, either starting in childhood to confirm the assigned sex or later if the assignment proves to be incorrect.

The purpose of this form of HRT is to cause the development of the secondary sex characteristics of the desired sex, such as voice deepening and a masculine pattern of hair, fat, and muscle distribution. It cannot undo many of the changes produced by naturally occurring puberty, which may necessitate surgery and other treatments (see below). The medications used in HRT of the FTM type include, mainly, androgens (namely testosterone) and GnRH analogues.

While HRT cannot undo the effects of a person's first puberty, developing secondary sex characteristics associated with a different gender can relieve some or all of the distress and discomfort associated with gender dysphoria, and can help the person to "pass" or be seen as the gender they identify with. Introducing exogenous hormones into the body impacts it at every level and many patients report changes in energy levels, mood, appetite, etc. The goal of HRT, and indeed all somatic treatments, is to provide patients with a more satisfying body that is more congruent with their gender identity.

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