They assist in preparing girls' bones for rapid growth in adolescence. In women, estrogens maintain tone and elasticity of the urinary and reproductive organs and protect against bone thinning. Men also make the hormone, but only a small amount. In both men and women, estrogens help stabilize the opening and closing of blood vessels. Women manufacture most estrogens in the ovaries and adrenal gland, with increases during pregnancy from the placenta.
Men produce low levels of estrogens in the testes.
Fat cells also may produce estrogens. Therapeutic estrogens made synthetically or derived from pregnant mares' urine are formulated as oral, injectable and vaginal preparations and, most recently, as stick-on patches. Because of the effects estrogen deficiency can have on the vagina, some menopausal and postmenopausal women have pain during or after intercourse. Estrogen therapy helps relieve this symptom by thickening the vaginal wall. Medical evidence hasn't proven that estrogens keep a woman feeling young or foster soft or unwrinkled skin.