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Estradiol |
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| Estradiol is a female hormone that is produced by cells that live in the follicle (nest) around the developing egg. There are three
estrogens Estrone E-1, Estradiol E-2 and Estriol E-3. Estradiol is a steroid with two alcohol or hydroxy groups that is synthesized by the ovaries, placenta, and testis. This chemical is the most potent of the mammalian estrogenic hormones. Estradiol, like other sex steroids, is derived from cholesterol. After side chain cleavage and either utilizing the delta-5 pathway or the delta-4 pathway androstenedione is the key intermediary. Androstendione is either converted to testosterone which in turn undergoes aromatization to estradiol, or, alternatively, androstendione is aromatized to estrone which is converted to estradiol. During the reproductive years most estradiol in women is produced by the granulosa cells of the ovaries by aromatization of testosterone from the theca cells, or conversion of estrone to estradiol. Smaller amounts of estradiol are also produced by the adrenal cortex. Estradiol is produced particularly in the maturing ovarian follicles during the reproductive phase of a woman's life. In men, the testes produce some estradiol. An additional source of estradiol in both sexes is peripheral aromatization of testosterone to estradiol. Particularly fat cells are active to convert precursors to estradiol, and will continue to do so even after the menopause. |
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Functions and health benefits of estradiol |
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Estradiol is the most bioactive and potent of the estrogens found in the body, and the most predominant estrogen produced by the human ovary prior to menopause. Estradiol is responsible for over 400 functions in the human body. In men, the hormone inhibits growth of cells in the prostate gland. In women, estradiol replaces deficient natural levels of estrogen in the body. Estradiol slows the breakdown of bones and is prescribed to women that do not produce estradiol. Estradiol may be very effective for the symptomatic relief of hot flashes, genitourinary symptoms, osteoporosis prophylaxis, psychological well-being and reduction of coronary artery disease. Estradiol works best when used with calcium/vitamin D supplements, weight-bearing exercises like walking, or physical therapy. Estradiol may also be used to lower high cholesterol in women who have gone through menopause. It may be used vaginally as a cream to treat irritation and itching in the vagina caused by menopause. |
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Side effects of estradiol |
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For women, vaginal bleeding (breakthrough bleeding, spotting) may occur. Estradiol increases the risk of developing a condition (endometrial hyperplasia) that may lead to cancer of the lining of the uterus. Treatment with estradiol long-term may increase the risk of stroke. Other possible estradiol side effects include rash, changes in mood, jaundice, breast tenderness, nausea and vomiting, endometriosis, oedema, thromboembolism, gallstones, weight changes, high blood pressure, migraine, and menstrual spotting between periods. |
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Contraindications, interactions, precautions |
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Estrogens, when used in women after menopause, may increase the risk of cancer of the uterus. Unusual vaginal bleeding may be a warning sign for this type of cancer. Estrogens can inhibit the metabolism of cyclosporine, resulting in increased cyclosporine blood levels. Do not take estradiol, if you have any of the following conditions: porphyria, vaginal bleeding of an unknown cause, known or suspected breast cancer except where the cancer has spread, a history of blood clots caused by estrogen use, a tumor where estrogen makes it grow.
Before taking estradiol, tell your doctor if you are taking any of the following medicines: carmustine, chloroquine, dantrolene, daunorubicin, gold salts, divalproex, acetaminophen, amiodarone, anticonvulsants, anti-infective drugs, antithyroid agents, etretinate, methotrexate, oral contraceptives, methyldopa, naltrexone, phenothiazines, plicamycin, hydroxychloroquine, mercaptopurine, steroids, bromocriptine or cyclosporine. |
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