causes menstrual periods in women who are premenopausal. If you have problems swallowing Prometrium, take your dose with a glass of water while in the standing position.

Prometrium Overview


Prometrium is a prescription medication used to cause menstrual periods in women who are premenopausal but have stopped having periods due to low progesterone levels in their bodies. It is also used to prevent abnormal thickening of the lining of the uterus in women taking estrogen.

Prometrium belongs to a group of drugs called progestins, which work to bring menstruation by causing "withdrawal" bleeding when the medication is stopped. 

This medication comes in capsule form and is taken once a day, at bedtime for 10 or 12 continuous days per cycle, depending on the condition being treated.

Common side effects of Prometrium include headaches, breast pain, and irregular vaginal bleeding or spotting.

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  • Other
  • Amenorrhea
  • Endometrial Hyperplasia
  • Infertility, Female
  • Uterine Hemorrhage

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Prometrium Cautionary Labels


Uses of Prometrium

Prometrium is a prescription medication used to cause menstruation in women with an absence of menstrual periods due to a decrease in progesterone. Prometrium is also used in combination with estrogen-containing medications in postmenopausal women with a uterus (womb) to reduce the risk of developing cancer of the uterus.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.


Prometrium Drug Class

Prometrium is part of the drug class:

Side Effects of Prometrium

Side effects are grouped by how serious they are and how often they happen when you are treated:

Serious, but less common side effects include:

  • Risk to the Fetus: Cases of cleft palate, cleft lip, hypospadias, ventricular septal defect, patent ductus arteriosus, and other congenital heart defects.
  • Abnormal Blood Clotting: Stroke, heart attack, pulmonary embolus, visual loss or blindness.

Some of the warning signs of serious side effects include:

  • Changes in vision or speech
  • Sudden new severe headaches
  • Severe pains in your chest or legs with or without shortness of breath, weakness and fatigue
  • Dizziness and faintness
  • Vomiting

Call your healthcare provider right away if you get any of these warning signs, or any other unusual symptoms that concern you.

Less serious, but common side effects include:

  • Headaches
  • Breast pain
  • Irregular vaginal bleeding or spotting
  • Stomach/abdominal cramps, bloating
  • Nausea and vomiting
  • Hair loss
  • Fluid retention
  • Vaginal yeast infection

These are not all the possible side effects of Prometrium capsules. For more information, ask your healthcare provider or pharmacist for advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

What you can do to lower your chances of getting a serious side effect with Prometrium:

  • Talk with your healthcare provider regularly about whether you should continue taking Prometrium.
  • See your healthcare provider right away if you get unusual vaginal bleeding while taking Prometrium.
  • Have a pelvic exam, breast exam, and mammogram (breast X-ray) every year unless your healthcare provider tells you something else. If members of your family have had breast cancer or if you have ever had breast lumps or an abnormal mammogram, you may need to have breast exams more often.
  • If you have high blood pressure, high cholesterol (fat in the blood), diabetes, are overweight, or if you use tobacco, you may have higher chances for getting heart disease. Ask your healthcare provider for ways to lower your chances for getting heart disease.

Prometrium Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Some medicines may affect how Prometrium works. Prometrium may also affect how your other medicines work.

Prometrium Precautions

  • Progestins with estrogens should not be used to prevent heart disease, heart attacks, strokes, or dementia.
  • Using progestins with estrogens may increase your chance of getting heart attacks, strokes, breast cancer, and blood clots.
  • Using progestins with estrogens may increase your chance of getting dementia, based on a study of women age 65 and older.
  • You and your healthcare provider should talk regularly about whether you still need treatment with Prometrium.

Do not start taking Prometrium if you:

  • Have unusual vaginal bleeding
  • Currently have or have had certain cancers
    Estrogen plus progestin treatment may increase the chance of getting certain types of cancers, including cancer of the breast or uterus. If you have or have had cancer, talk with your healthcare provider about whether you should take Prometrium.
  • Had a stroke or heart attack
  • Currently have or have had blood clots
  • Currently have or have had liver problems
  • Are allergic to Prometrium or any of its ingredients
  • Think you may be pregnant

Do not start taking Prometrium capsules if you are allergic to peanuts. THIS PRODUCT CONTAINS PEANUT OIL AND SHOULD NOT BE USED IF YOU ARE ALLERGIC TO PEANUTS.

Prometrium Food Interactions

Grapefruit and grapefruit juice may interact with Prometrium and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.


Inform MD

Tell your healthcare provider:

  • If you are pregnant or breastfeeding.
  • About all of your medical problems. Your healthcare provider may need to check you more carefully if you have certain conditions, such as asthma (wheezing), epilepsy (seizures), diabetes, migraine, endometriosis, lupus, problems with your heart, liver, thyroid, or kidneys, or have high calcium levels in your blood.
  • About all the medicines you take.

Prometrium and Pregnancy

Prometrium should not be taken during pregnancy.

Researchers have theorized that having low progesterone levels before a miscarriage may play a role in causing miscarriage. Others suggest that low progesterone levels indicate the body is preparing to miscarry a pregnancy for reasons unknown. More research is needed to determine if Prometrium is beneficial.

If your doctor prescribes Prometrium during pregnancy to prevent a miscarriage or other pregnancy complications, you should know that although the prescribing information indicates Prometrium should not be used during pregnancy, some research suggests there may not be an increased risk to the fetus.

Discuss your concerns about Prometrium use during pregnancy with your doctor.

Prometrium and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed.

The hormone in Prometrium can pass into your breast milk.

Prometrium Usage

  • Take Prometrium at bedtime, because some women become very drowsy and/or dizzy after taking Prometrium. In a few cases, symptoms may include blurred vision, difficulty speaking, difficulty with walking, and feeling abnormal. If you experience these symptoms, discuss them with your healthcare provider right away.
  • If you experience difficulty in swallowing Prometrium, it is recommended that you take your daily dose at bedtime with a glass of water while in the standing position.

Prometrium Dosage

  • Prevention of Endometrial Hyperplasia: A postmenopausal woman with a uterus who is taking estrogens should take a single daily dose of 200 mg Prometrium at bedtime for 12 continuous days per 28-day cycle.
  • Secondary Amenorrhea: Prometrium may be given as a single daily dose of 400 mg at bedtime for 10 days.

Prometrium Overdose

If you take too much Prometrium, call your local Poison Control Center or seek emergency medical attention right away.

Other Requirements

Store Prometrium at room temperature 15° to 30°C (59° to 86°F).

Protect from excessive moisture (keep out of bathroom).

Keep this and all medicines out of the reach of children.

Prometrium FDA Warning


Cardiovascular Disorders and Probable Dementia

Estrogens plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia.

The Women's Health Initiative (WHI) estrogen plus progestin substudy reported increased risks of deep vein thrombosis, pulmonary embolism, stroke and myocardial infarction in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral conjugated estrogens (CE) [0.625 mg] combined with medroxyprogesterone acetate (MPA) [2.5 mg], relative to placebo.

The WHI Memory Study (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.

Breast Cancer

The WHI estrogen plus progestin substudy also demonstrated an increased risk of invasive 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.

Progestins with estrogens should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.