Conjugated estrogens are a mixture of several different estrogens. The mixture is derived from equine (horse) urine. Estrogens have widespread effects on many tissues in the body. Conjugated estrogens are used for symptomatic treatment of the symptoms associated with menopause ( for example, hot flashes and vaginal dryness), prevention of bone fractures associated with osteoporosis, reducing of risk of heart attacks and strokes, dysfunctional (excessive and painful) uterine bleeding, and, occasionally, prostate cancer.
Conjugated estrogens are female sex hormones necessary for many processes in the body. Methyltestosterone is a naturally occurring androgen ("male" sex hormone) that is produced in the testes in men and, in small amounts, by the ovaries and the brain in women. The combination, conjugated estrogens and methyltestosterone, is used to treat symptoms of menopause that have not responded to estrogen therapy alone. Most often, conjugated estrogens and methyltestosterone is used to treat the symptoms of menopause in women who also have diminished libido (a declining interest in sexual activity).
Estrogens, when taken alone or in combination with a progestin, have been shown to reduce the risk for hip fracture due to osteoporosis by 25% and the risk of heart attack (myocardial infarction) and stroke by 40-50%. Estrogens cause growth and development of female sex organs and the maintenance of sexual characteristics, including growth of underarm and pubic hair and shaping of body contours and skeleton. Estrogens also increase secretions from the cervix and growth of the inner lining of the uterus (endometrium). Estrogens reduce LDL-cholesterol ("bad" cholesterol) and increase HDL-cholesterol ("good" cholesterol) concentrations.
Estrogens increase the rate of synthesis of DNA, RNA, and some proteins. Pituitary mass also increases. The secretion of gonadotropin-releasing hormone by the hypothalamus is reduced during estrogen administration, causing reduction in follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary.
Exogenous estrogens elicit all of the actions of endogenous estrogens. Estrogens are responsible for the growth and development of female sex organs and the maintenance of sex characteristics including growth of axillary and pubic hair and shaping of body contours and skeleton. At the cellular level, estrogens increase cervical secretions, cause proliferation of the endometrium, and increase uterine tone. Paradoxically, prolonged administration of estrogen can shrink the endometrium. During the preovulatory or nonovulatory phase of the menstrual cycle, withdrawal of estrogen can initiate menstruation; in the ovulatory phase, the decrease in progesterone secretion is the more significant factor causing menstruation.
Estrogens have a weak anabolic effect and also can affect bone calcium deposition and accelerate epiphysial closure. Estrogens generally have a favorable effect on blood lipids, and lack of estrogen is now recognized as a risk factor for myocardial infarction. Estrogens reduce LDL- and increase HCL-cholesterol concentrations. Serum triglycerides increase with estrogen administration. Estrogens, with or without a progestin, exert favorable changes in lipid profiles of postmenopausal women. Estrogens also enhance sodium and fluid retention.