Estradiol is a form of estrogen, a female sex hormone that regulates many processes in the body.

Estradiol injection is used to treat certain symptoms of menopause such as hot flashes and vaginal dryness, burning, or irritation. It is also used to treat a lack of estrogen that is caused by ovarian failure or a condition called hypogonadism.

Some forms of estradiol injection are used in men to treat the symptoms of prostate cancer. Estradiol treats only the symptoms of prostate cancer but does not treat the cancer itself.

Estradiol injection may also be used for purposes not listed in this medication guide.

You should not use estradiol if you are allergic to it, or if you have:

• unusual vaginal bleeding that has not been checked by a doctor;
• liver disease;
• a history of heart attack, stroke, or blood clot; or
• a history of hormone-related cancer, or cancer of the breast, uterus/cervix, or vagina.

Do not use estradiol if you are pregnant. Tell your doctor right away if you become pregnant during treatment.

Using estradiol can increase your risk of blood clots, stroke, or heart attack. You are even more at risk if you have high blood pressure, diabetes, high cholesterol, if you are overweight, or if you smoke.

Estradiol should not be used to prevent heart disease, stroke, or dementia, because this medicine may actually increase your risk of developing these conditions.

Tell your doctor if you have ever had:

• heart disease;
• liver problems, or jaundice caused by pregnancy or taking hormones;
• a thyroid disorder;
• gallbladder disease;
• kidney disease;
• asthma;
• epilepsy or other seizure disorder;
• migraine headaches;
• lupus;
• porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system);
• endometriosis or uterine fibroid tumors;
• high or low levels of calcium in your blood; or
• hereditary angioedema (an immune system disorder).

Using estradiol may increase your risk of cancer of the breast, uterus, or ovaries. Talk with your doctor about this risk.

Estradiol can slow breast milk production. Tell your doctor if you are breast-feeding.

Use Gynogen LA 20 (Intramuscular) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;
• signs of a stroke--sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance;
• signs of a blood clot--sudden vision loss, stabbing chest pain, feeling short of breath, coughing up blood, pain or warmth in one or both legs;
• swelling or tenderness in your stomach;
• jaundice (yellowing of the skin or eyes);
• memory problems, confusion, unusual behavior;
• unusual vaginal bleeding, pelvic pain;
• a lump in your breast; or
• high levels of calcium in your blood--nausea, vomiting, constipation, increased thirst or urination, muscle weakness, bone pain, lack of energy.

Common side effects may include:

• breast pain;
• headache;
• vaginal itching or discharge, changes in your menstrual periods, breakthrough bleeding;
• thinning scalp hair; or
• nausea, vomiting, bloating, stomach cramps.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid smoking. It can greatly increase your risk of blood clots, stroke, or heart attack while using estradiol.

Grapefruit may interact with estradiol and lead to unwanted side effects. Avoid the use of grapefruit products.