Warning signs of these serious side effects include breast lumps, unusual vaginal bleeding, dizziness, faintness, changes in speech, severe headaches, chest pain, shortness of breath, pain in the legs, changes in vision, and vomiting.Due to health risks observed with the combination of conjugated estrogens and medroxyprogesterone acetate in the Womens Health Initiative (WHI) studies (see below), the United States Food and Drug Administration (FDA) label for Estrace (estradiol) advises that estrogens should be used in menopausal hormone therapy only for the shortest time possible and at the lowest effective dose. While the FDA states that is unknown if these risks generalize to estradiol (alone or in combination with progesterone or a progestin), it advises that in the absence of comparable data, the risks should be assumed to be similar. When used to treat menopausal symptoms, the FDA recommends that discontinuation of estradiol should be attempted every three to six months via a gradual dose taper.The combination of bioidentical transdermal or vaginal estradiol and oral or vaginal progesterone appears to be a safer form of hormone therapy than the combination of oral conjugated estrogens and medroxyprogesterone acetate and may not share the same health risks. Advantages may include reduced or no risk of venous thromboembolism, cardiovascular disease, and breast cancer, among others. Overdose
Estrogens are relatively safe in overdose. During pregnancy, levels of estradiol increase to very high concentrations that are as much as 100-fold normal levels. In late pregnancy, the body produces and secretes approximately 100 mg of estrogens, including estradiol, estrone, and estriol, per day.
A 2017 meta-analysis found that estradiol had no effect on depressive symptoms in peri- and postmenopausal women. Hypogonadism
Estrogen is responsible for the mediation of puberty in females, and in girls with delayed puberty due to hypogonadism (low-functioning gonads, which can result in low sex hormone levels) such as in Turner syndrome, estradiol is used to induce the development of and maintain female secondary sexual characteristics such as breasts, wide hips, and a female fat distribution. It is also used to restore estradiol levels in adult premenopausal women with hypogonadism, for instance those with premature ovarian failure or who have undergone oophorectomy. It is used to treat women with hypogonadism due to hypopituitarism as well. Transgender women
Estradiol is used as part of feminizing hormone therapy for transgender women. The drug is used in higher dosages prior to sex reassignment surgery or orchiectomy to help suppress testosterone levels; after this procedure, estradiol continues to be used at lower dosages to maintain estradiol levels in the normal premenopausal female range. Birth control
Although almost all combined oral contraceptives contain the synthetic estrogen ethinylestradiol, natural estradiol itself is also used in some hormonal contraceptives, including in estradiol-containing oral contraceptives and combined injectable contraceptives. It is formulated in combination with a progestin such as dienogest, nomegestrol acetate, or medroxyprogesterone acetate, and is often used in the form of an ester prodrug like estradiol valerate or estradiol cypionate.