Estrogens Side Effects and Risks

by Food and Drug Administration (FDA)

(Page 2 of 2)

While estrogens have important uses, they also have serious risks.

Estrogens cause the uterine lining, or endometrium, to thicken in preparation for possible pregnancy. In the absence of a fertilized egg, female hormones called progestins cause the lining to shed, as menstruation. Therapy with estrogens alone can cause endometrial hyperplasia (overgrowth), a precursor to cancer in certain women.

In some studies, estrogen treatment of menopausal symptoms for longer than a year has increased the risk of endometrial hyperplasia/cancer. The greatest risk is with higher than usual dosages and with treatment that lasts five years or more. As a protective measure, some physicians may add 10 to 14 days dosage with a progestin to the monthly regimen. Women on this regimen will have cyclic bleeding similar to menstruation and even may experience premenstrual-like symptoms. Women who have had the uterus surgically removed have no risk of endometrial cancer.

There are concerns about the long-term effects of progestins, particularly the possibility that they may raise harmful LDL (low-density lipoprotein) cholesterol while lowering beneficial HDL (high-density lipoprotein) cholesterol.

Large doses of estrogens, such as a 30-milligram (mg) daily dose to treat breast cancer, are linked to increased risk of heart attack and blood-clot conditions. (By comparison, the usual daily dosage for menopausal symptoms is 0.01 to 0.05 mg of ethinyl estradiol or 0.3 to 1.25 mg of conjugated estrogens.)

Cigarette smoking may increase the risk of serious blood clots in women taking estrogens, the risk increasing with the patient's age and amount smoked. Smoking also may make estrogens less effective.

Breast cancer has been reported in men on estrogens; men receiving this drug should see their doctors at least annually.

It's unknown whether estrogen use increases a woman's risk of breast cancer. Like all women, those taking estrogens should have annual medical checkups that include breast examination and should practice breast self-examination.

People taking estrogens should get emergency medical help if any of the following symptoms of blood clots occurs:

• sudden or severe headache
• sudden loss of coordination
• sudden loss or change of vision
• pains in the chest, groin or leg, especially in the cal
• sudden, unexplained shortness of breath
• sudden slurring of speech
• weakness or numbness in an arm or leg

Check with the doctor as soon as possible if any of the following estrogen side effects occurs:

• swollen feet and lower legs
• rapid weight gain
• breast pain
• increased breast size
• blood-filled skin sores
• changes in vaginal bleeding
• confusion
• general feeling of illness
• joint or muscle aches
• breast lumps or discharge from nipples
• mental depression
• persistent nausea or vomiting
• pains in the stomach, side or abdomen
• sores in the mouth or nose or on lower legs, thighs, forearms, genitals, soles, or palms
• uncontrolled jerky muscle movement
• unusual tiredness
• yellow eyes or skin

Estrogens may foster bleeding or overgrowth of the gums. Regular cleaning by a dental professional and plaque control by the patient will minimize problems.

Side effects requiring medical care only if severe or bothersome include mild acne, stomach bloating, appetite loss, problems wearing contact lenses due to dry eyes, and migraine headaches. Exposure to the sun can cause brown, blotchy skin spots, so it's wise to use a sunscreen.

Some patients may have other side effects. Patients who develop new health problems or have questions should check with the doctor.

Estrogens may affect certain diagnostic laboratory tests, such as the glucose tolerance test, so it's important that patients using estrogens tell the doctor or laboratory personnel performing the procedure.

Before Taking This Medicine

Before deciding to use estrogen, it's best to talk to the doctor about the good it will do and the risks it poses.

To keep risks as low as possible, patients should tell the doctor:

If they might be pregnant. Estrogen therapy during pregnancy has been associated with an increased risk of birth defects, such as defects in the reproductive organs. Breast-feeding mothers shouldn't take estrogen because it passes into the breast milk, and its effect on infants is unknown.

If they follow a special diet or ever had an unusual or allergic response to estrogen or to foods, dyes or preservatives.

If they have a family history of bone disease, cancer (especially breast cancer in mother, sister or aunt), endometriosis (in which endometrial tissue becomes implanted elsewhere), epilepsy, fibroids, gallbladder disease, heart or circulatory disease, stroke, kidney disease, liver disease, migraine headaches, or excess calcium in the blood.

If they smoke or take other prescription or over-the-counter medicine. Estrogens may alter the effect of some other drugs, including drugs to prevent blood clots, diabetes drugs, calcium supplements, and a breast cancer drug called tamoxifen.

Proper Storage

Store estrogens away from humidity, heat, and direct light, which can destroy the drug's effectiveness. Humidity from steamy baths and showers make the bathroom medicine cabinet a poor place to store drugs.

Keep estrogens out of the reach of children. Caps that are child-resistant aren't necessarily child-proof.

Discard estrogens when they're no longer needed or when the expiration date is past. Be sure to dispose of the drug (including used patches) out of the reach of children.

Dixie Farley

Types of Estrogen

chlorotrianisene
diethylstilbestrol
estradiol
conjugated estrogens
esterified estrogens
estrone
estropipate
ethinyl estradiol
quinestrol

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.