Skip to main content

Conjugated estrogens (By mouth)

Conjugated Estrogens (KON-joo-gay-ted ES-troe-jenz)

Treats hot flashes and other symptoms of menopause or low amounts of estrogen. Prevents osteoporosis (thinning of the bones) after menopause. Also treats symptoms of advanced breast or prostate cancers. Also treats certain conditions in women before menopause if their ovaries do not make enough estrogen naturally. This medicine is a mixture of estrogens (female hormone).

Brand Name(s):

Premarin, Premphase

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had a severe allergic reaction to estrogens. You should not use this medicine if you have liver disease or cancer of the breast, uterus, or ovary. You should not use this medicine if you have a history of blood clotting problems, heart attack, or stroke. Do not use this medicine if you may be pregnant, are breastfeeding, or have unusual vaginal bleeding that has not been checked by a doctor. This medicine should not be used to prevent heart disease, heart attack, stroke, or dementia.

How to Use This Medicine:


  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
  • You may take this medicine with or without food.
  • Take this medicine at the same time each day.
  • It is important that you eat a well-balanced diet. Your doctor may want you to take calcium or vitamin D supplements while you take this medicine.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.

If a dose is missed:

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine:

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you also use a blood thinner (such as warfarin, Coumadin®), thyroid replacement (Synthroid®), or other female hormones (such as Prometrium®, Provera®).

Warnings While Using This Medicine:

  • It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
  • Make sure your doctor knows if you have endometriosis or a history of cancer. Tell your doctor if you have asthma, diabetes, epilepsy (seizures), gallbladder disease, high or low calcium in the blood, kidney disease, lupus, migraine headaches, porphyria, or thyroid problems. Your doctor should know if you have heart disease, high blood pressure, high blood cholesterol, or a family history of high cholesterol. Tell your doctor if you have ever had liver problems caused by pregnancy or estrogen.
  • Your risk of heart attack, stroke, blood clots, dementia, or breast cancer may increase if you use large doses of this medicine over a long period of time. Talk with your doctor about this risk.
  • Your risk of blood clots or stroke from this medicine is higher if you smoke. Your risk is also increased if you have diabetes or high cholesterol, or if you are overweight.
  • This medicine may increase your risk of breast and ovarian cancer. Talk to your doctor if you have concerns about this risk.
  • Your risk of cancer of the uterus may be increased if you use this medicine without a progestin medicine. Check with your doctor right away if you have unusual vaginal bleeding while you are using this medicine.
  • Stop using this medicine and check with your doctor immediately if severe headache or sudden loss of vision or any other change in vision occurs while you are using this medicine. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).
  • Tell any doctor or dentist who treats you that you are using this medicine. You may need to stop using this medicine several days before you have surgery or medical tests.
  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments. Pelvic exam, breast exam, and mammogram (breast x-ray) may be needed to check for side effects.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Breast changes, lumps, or discharge (in women or men)
  • Chest pain, shortness of breath, or coughing up blood
  • Numbness or weakness in your arm or leg, or on one side of your body
  • Pain in your lower leg (calf)
  • Seizures
  • Sudden or severe headache, problems with vision, speech, or walking
  • Swelling in your face, hands, ankles, or feet
  • Unusual vaginal bleeding
  • Yellowing of your skin or the whites of your eyes

If you notice these less serious side effects, talk with your doctor:

  • Back pain
  • Breast pain or tenderness
  • Change in weight or hair growth
  • Headache
  • Nausea, vomiting, stomach pain, bloating, or gas
  • Runny or stuffy nose, sore throat, or fever

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 4/4/2014

Copyright © 1984- Thomson Micromedex. All rights reserved.

Thomson & A.D.A.M