This installment in a series of articles on commonly prescribed drugs is about estrogens. The focus is on estrogen deficiency problems. Estrogens are the hormones mainly responsible for female sex characteristics. 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.