Synthetic Conjugated Estrogens, A

All estrogen products mimic the effects of endogenous estrogens in the body which are responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Estrogens act by binding to estrogen receptors on a wide variety of tissues in the body and modulating the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH) through a negative feedback mechanism. Prior to menopause, the primary source of estrogen is the ovarian follicle, which secretes 70-500 micrograms of estradiol daily, depending on the phase of the menstrual cycle. However, once a woman stops ovulating there is a sharp decline in the production of progesterone and estradiol by the ovaries and a consequent fluctuation in LH and FSH due to a lack of feedback control. This shift in hormone production is largely responsible for many of the symptoms experienced during and after menopause and includes hot flashes and other vasomotor symptoms, painful intercourse, vaginal dryness, and vulvovaginal atrophy. These symptoms are able to be reduced by replacing many of the hormones lost during and following menopause with synthetic or naturally occurring forms, in a therapy known as Hormone Replacement Therapy (HRT).