What Happens If Men Take Female Hormones?

Taking estrogens, or feminizing hormones, affects body hair, breast development, skin, fat distribution and muscle mass, according to Transgender Care. The genitalia and prostate gland are also affected. Long-term use may result in infertility and may potentially reduce the risk of developing cardiovascular disease. Changes in facial hair and voice pitch are minor.

Many of these effects take a long time to appear and vary greatly among individuals, reports Transgender Care. On average, estrogen's effect on breast tissue development is less pronounced than the genetic female population's and may take up to two years to develop fully. The growth of body hair lessens noticeably over the period of several years, with its effect on arm, leg and chest hair being more pronounced than in the armpits, areola and pubic area. Female hormone therapy lessens the size of the testes and penis, reducing the production of sperm and testosterone.

Estrogen therapy can increase an individual's risk for developing Type 2 diabetes or blood clots, warns Gender Centre. Breast growth may be accompanied by discharge known as galactorrhea. The metabolism often slows down, and muscle mass is more difficult to acquire, resulting in weight gain for many patients.

Estrogen and anti-androgen therapy are also used to treat benign prostate enlargement, reports Transgender Care. Patients have reported difficulty urinating.