Due to its estrogenic activity, estradiol has antigonadotropic effects and can inhibit fertility and suppress sex hormone production in both women and men. Estradiol differs from non-bioidentical estrogens like conjugated estrogens and ethinylestradiol in various ways, with implications for tolerability and safety.Estradiol was discovered in 1933. It became available as a medication that same year, in an injectable form known as estradiol benzoate. Forms that were more useful by mouth, estradiol valerate and micronized estradiol, were introduced in the 1960s and 1970s and increased its popularity by this route. Estradiol is also used as other prodrugs, like estradiol cypionate. Related estrogens such as ethinylestradiol, which is the most common estrogen in birth control pills, and conjugated estrogens (brand name Premarin), which is used in menopausal hormone therapy, are used as medications as well. In 2020, it was the 59th most commonly prescribed medication in the United States, with more than 11 million prescriptions. Medical uses
Hormone therapy
Menopause
Estradiol is used in menopausal hormone therapy to prevent and treat moderate to severe menopausal symptoms such as hot flashes, vaginal dryness and atrophy, and osteoporosis (bone loss). As unopposed estrogen therapy (using estrogen alone without progesterone) increases the risk of endometrial hyperplasia and endometrial cancer in women with intact uteruses, estradiol is usually combined with a progestogen like progesterone or medroxyprogesterone acetate to prevent the effects of estradiol on the endometrium. This is not necessary if the woman has undergone a hysterectomy (surgical removal of the uterus).
Estradiol/progesterone (E2/P4), sold under the brand names Bijuva and Juvenum, is a combined estrogen and progestogen medication which is used in the treatment of menopausal symptoms in postmenopausal women. It contains estradiol, an estrogen, and progesterone, a progestogen, and is available in both oral and intramuscular formulations. E2/P4 differs from other estrogen–progestogen formulations in that the sex-hormonal agents used are bioidentical. Bijuva (formerly TX-001HR/TX-12-001HR) is an oral combination of estradiol (E2), an estrogen, and progesterone (P4), a progestogen, which was developed by TherapeuticsMD and is approved in the United States for the treatment of menopausal symptoms in women. It is also under development for the treatment of endometrial hyperplasia in women. The medication contains 2 mg solubilized E2 and 200 mg P4 in each gelatin capsule. It is the first combination of E2 and P4 in oral capsule form that has been developed for clinical use. Bijuva is currently in phase III clinical trials for endometrial hyperplasia. The medication was approved by the Food and Drug Administration for the treatment of menopausal symptoms in October 2018.E2/P4 is available as an aqueous suspension of E2 and P4 encapsulated in microspheres for use by intramuscular injection once a month under the brand name Juvenum in Mexico. It was introduced for the treatment and prevention of menopausal symptoms like hot flashes, vulvovaginal symptoms, and osteoporosis in December 2014. The combination contains relatively low doses of E2 and P4 (1 mg and 20 mg, respectively) contained within microspheres that results in a slower release of the hormones.