Estradiol: What to Know Before You Take It
Also known as Estrace, Climara, Vivelle-Dot
Other names: estradiol-hemihydrate, estradiol-hemihydrate, estradiol-cypionate, estradiol-valerate, injectable-estradiol, estrace, climara
Estradiol is the primary endogenous estrogen and is FDA-approved in multiple forms including injectable formulations. Compounded injectable estradiol (as hemihydrate, cypionate, or valerate) is also available through licensed pharmacies for menopausal hormone therapy or transgender feminizing hormone therapy.
FDA boxed warning
WARNING: ENDOMETRIAL CANCER, CARDIOVASCULAR DISORDERS, BREAST CANCER and PROBABLE DEMENTIA Estrogen-Alone Therapy Endometrial Cancer There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens. Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding [see WARNINGS, Malignant Neoplasms, Endometrial Cancer ]. Cardiovascular Disorders and Probable Dementia Estrogen-alone therapy should not be used for the prevention of cardiovascular disease or dementia [see CLINICAL STUDIES and WARNINGS, Cardiovascular Disorders, and Probable Dementia ]. The Women’s Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 7.1 years of treatment with daily oral conjugated estrogens (CE) [0.625 mg]-alone, relative to placebo [see CLINICAL STUDIES and WARNINGS, Cardiovascular Disorders ]. The WHI Memory Study (WHIMS) estrogen-alone ancillary study of WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 5.2 years of treatment with daily CE (0.625 mg)-alone, relative to placebo. It is unknown whether this finding applies to younger postmenopausal women [see CLINICAL STUDIES and WARNINGS, Probable Dementia and PRECAUTIONS, Geriatric Use ]. In the absence of comparable data, these risks should be assumed to be similar for other doses of CE and other dosage forms of estrogens. Estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman. Estrogen Plus Progestin Therapy Cardiovascular Disorders and Probable Dementia Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia [see CLINICAL STUDIES and WARNINGS, Cardiovascular Disorders, and Probable Dementia ]. The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism (PE), stroke and myocardial infarction (MI) in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral CE (0.625 mg) combined with medroxyprogesterone acetate (MPA) [2.5 mg], relative to placebo [see CLINICAL STUDIES and WARNINGS, Cardiovascular Disorders ]. The WHIMS estrogen plus progestin ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with daily CE (0.625 mg) combined with MPA (2.5 mg), relative to placebo. It is unknown whether this finding applies to younger postmenopausal women [see CLINICAL STUDIES and WARNINGS, Probable Dementia and PRECAUTIONS, Geriatric Use ]. Breast Cancer The WHI estrogen plus progestin substudy also demonstrated an increased risk of invasive breast cancer [see CLINICAL STUDIES and WARNINGS, Malignant Neoplasms, Breast Cancer ]. In the absence of comparable data, these risks should be assumed to be similar for other doses of CE and MPA, and other combinations and dosage forms of estrogens and progestins. Estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.
In plain language
What Estradiol is used for
- Menopausal hormone therapy (hot flashes, bone protection)
- Transgender feminizing hormone therapy
- Hypogonadism in females
Taking this medicine
How it is administered
- Subcutaneous injection
- Intramuscular injection
Read before you decide
Risks and precautions
Risks and warnings
- Nausea, bloating, breast tenderness
- Irregular periods or spotting
- Mood changes
- Blood clot risk (VTE)
Who should not take it
- Estrogen-receptor-positive breast cancer
- History of blood clots or clotting disorder
- Undiagnosed vaginal bleeding
Medication review
Estradiol drug interactions
FDA safety data
Most-reported side effects
Based on 190,011 FAERS reports. Reports do not prove the drug caused the effect.
Regulatory record
FDA recalls (20)
Failed Impurities/Degradation Specifications: This recall is being initiated due to out-of-specification results total impurities.
Recalling firm: Glenmark Pharmaceuticals Inc., USA
Defective Container; packets were found to be either empty or partially full.
Recalling firm: ANI Pharmaceuticals, Inc.
Failed Impurities/Degradation Specifications
Recalling firm: Glenmark Pharmaceuticals Inc., USA
Failed Content Uniformity Specifications
Recalling firm: AvKARE
Failed Impurities/Degradation Specifications.
Recalling firm: Zydus Pharmaceuticals (USA) Inc
Failed Impurities/Degradation Specifications.
Recalling firm: Zydus Pharmaceuticals (USA) Inc
Failed Dissolution Specifications
Recalling firm: Teva Pharmaceuticals USA, Inc
Discoloration: discolored tablets (shades of blue) mixed in with the white inert remainder tablets.
Recalling firm: Teva Pharmaceuticals USA, Inc
Discoloration: discolored tablets (shades of blue) mixed in with the white inert remainder tablets.
Recalling firm: Teva Pharmaceuticals USA, Inc
Failed Stability Specification and Failed Impurities/Degradation Specifications: out of specification for inactive content ascorbic acid and MTHFRC-7impurity test
Recalling firm: Lupin Pharmaceuticals Inc.
Failed Content Uniformity Specifications: The Spray Content Uniformity (SCU) requirement for Standard Deviation did not meet the requirement at the 18-month stability time point.
Recalling firm: Padagis US LLC
CGMP Deviations: Products were exposed to temperatures outside of the products labeled storage conditions.
Recalling firm: CARDINAL HEALTHCARE
Common questions
Patient questions
Is injectable estradiol better than oral?
Injectable estradiol bypasses first-pass liver metabolism, which may reduce some VTE and metabolic risks compared to oral forms. This is an area of ongoing research. A licensed provider evaluates which form and route is most appropriate based on your health history.
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This information is educational — not medical advice.
This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.
Sources & References
- FDA structured product labeling for Estradiol
- U.S. Food & Drug Administration — openFDA Drug Labeling API
- U.S. National Library of Medicine — RxNorm drug nomenclature
- FDA: Estradiol drug products
- NAMS: Hormone Therapy Position Statement
Learn more about where our data comes from and how we write and review medical content.