Prometrium (Progesterone) - Oral


Prometrium (progesterone) has a boxed warning, the strictest safety warning assigned to a drug label by the Food and Drug Administration (FDA). The boxed warning states:

Estrogens and progestin therapy should not be used to prevent heart disease or dementia. Taking estrogen plus progestin long term has been shown to increase the chances of developing deep vein thrombosis, pulmonary embolism, stroke, and heart attack in postmenopausal women. The combination can also lead to a higher risk of dementia in postmenopausal women 65 years and older.

Combined estrogen and progestin treatment may also increase the risk of invasive breast cancer.

What Is Prometrium?

Prometrium (progesterone) is an oral prescription medication containing the hormone progesterone. It is used to prevent endometrial hyperplasia in postmenopausal people with a uterus who are also receiving conjugated estrogen tablets and to treat secondary amenorrhea (the absence of a menstrual period).

This medication helps to regulate menstrual periods by bringing balance to the levels of progesterone in the body.

Taking progesterone with estrogen can increase the risk of heart-related problems (e.g., heart attack, stroke, blood clots), breast cancer, and dementia in postmenopausal women. This medication should not be used with estrogen to prevent heart disease or dementia.

Prometrium is taken by mouth as a capsule. Prometrium is also available as an intramuscular injectable and vaginal gel, ring, or insert. This article focuses on its oral formulation.

Drug Facts

Generic Name: Progesterone

Brand Name(s): Prometrium

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Endocrine-metabolic agent, female reproductive agent

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Progesterone

Dosage Form(s): Capsule

What Is Prometrium Used For?

Prometrium is used to bring balance to the natural levels of hormones in the body. This can be used for:

How to Take Prometrium

It is important to always take this medication as directed by your healthcare provider. Treatment regimens for Prometrium vary based on what it is being used for:

  • Amenorrhea: Take 400 milligrams (mg) once daily at bedtime for 10 days. You can take each dose with or without food, but take it with a full glass of water.
  • Endometrial hyperplasia prevention: Take 200 milligrams (mg) once daily at bedtime for 12 days per 28-day cycle.

If you have difficulty swallowing pills, take them with a glass of water while in a standing position.


Store all forms of Prometrium at room temperature (between 68 F and 77 F) in a dry place. Do not store it in the bathroom or kitchen. Containers should be closed tightly and kept away from direct sunlight.

Off-Label Uses

There are instances where Prometrium may be prescribed for reasons other than what has been approved by the FDA. This is called off-label use.

According to research, vaginal progesterone may be used to prevent spontaneous preterm birth. Progesterone, through vaginal administration, can be given to pregnant people at risk for preterm labor. Preterm birth is defined as any live birth that is before 37 weeks of pregnancy.

How Long Does Prometrium Take to Work?

Oral progesterone works relatively quickly after taking it. It typically reaches its peak in the bloodstream within three hours.

What Are the Side Effects of Prometrium?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider or a pharmacist. You may report side effects to the Food and Drug Administration (FDA) at or 1-800-FDA-1088.

Common Side Effects

The most common side effects of Prometrium include:

There could be other side effects not mentioned. Contact your pharmacist or healthcare provider for any further advice or concerns about side effects.

Severe Side Effects

Life-threatening side effects from Prometrium are rare. However, some symptoms are severe and should not be taken lightly. Get medical help immediately if you experience symptoms such as:

  • Signs of an allergic reaction such as a rash or hives, trouble breathing, wheezing, or tightness in the chest or throat
  • Signs of liver problems such as dark urine, feeling tired, appetite loss, stomach pain, light-colored stools, vomiting, or yellowing of the skin or whites of the eyes (jaundice)
  • Shortness of breath 
  • Extreme dizziness or passing out 
  • Vaginal itching or discharge or vaginal bleeding 
  • Pain during urination 
  • Stroke symptoms such as trouble walking, eyesight changes, weakness on one side of the body, drooping on one side of the face, or a change in balance
  • Signs of a blood clot such as sudden chest pain, coughing up blood, pain in the leg or arm, and trouble speaking or breathing 
  • Depression or mood changes 
  • Unusual weight gain from fluid

Although rare, call your healthcare provider immediately if you experience any of these serious side effects. Dial 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Long-Term Side Effects

Long-term use of Prometrium should be considered only at the discretion of your healthcare provider. Taking this medication over an extended period may increase the risk of endometrial or breast cancer in some postmenopausal women.

Long-term use of this medication may also increase your risk for heart attack, stroke, or blood clots. In clinical studies, this risk was demonstrated in people taking medroxyprogesterone acetate (MPA), a hormonal medication of the progestin type, and daily estrogen therapy for 5.6 years.

Taking Prometrium with estrogens may also increase the risk of dementia in postmenopausal women 65 years and older. This was shown in people taking MPA and estrogen for four years.

Report Side Effects

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the FDA at or 1-800-FDA-1088.

Dosage: How Much Prometrium Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For prevention of thickening of the lining of the uterus (endometrial hyperplasia):
      • Adults—200 milligrams (mg) per day, taken as a single dose at bedtime, for 12 continuous days per 28-day menstrual cycle.
      • Children—Use is not recommended.
    • For treatment of unusual stopping of menstrual period (amenorrhea):
      • Adults—400 milligrams (mg) per day, taken as a single dose at bedtime, for 10 days.
      • Children—Use is not recommended.

Missed Dose

If you miss a dose, take it as soon as you think about it. If it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take extra doses or multiple doses at the same time.

Overdose: What Happens If I Take Too Much Prometrium?

Call your healthcare provider if you accidentally take more than the prescribed dose. If you take too much Prometrium and start experiencing symptoms, stop taking your medication and seek medical attention.

What Happens If I Overdose on Prometrium?

If you think you or someone else may have overdosed on Prometrium, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Prometrium, call 911 immediately.


Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and does not cause unwanted effects. Pelvic exam, breast exam, and mammogram (breast x-ray) may be needed to check for unwanted effects, unless your doctor tells you otherwise.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.

Stop using this medicine and check with your doctor right away if you have pain in the chest, groin, or legs, especially the calves; difficulty with breathing; a sudden, severe headache; slurred speech; a sudden, unexplained shortness of breath; a sudden loss of coordination; or vision changes while using this medicine.

There is a very slight chance that this medicine could increase the risk of breast cancer and endometrial (lining of the uterus) cancer in some women. Talk to your doctor about this risk. Make sure your doctor knows if anyone in your family has had breast cancer or endometrial cancer.

Using large doses of this medicine over a long period of time and using it with an estrogen medicine may increase your risk of heart attack, stroke, blood clots, or dementia. Talk with your doctor about these risks.

Your risk of heart disease 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. Talk with your doctor about ways to stop smoking. Keep your diabetes under control. Ask your doctor about diet and exercise to control your weight and blood cholesterol level.

Tell the medical doctor or dentist in charge that you are using this medicine before any kind of surgery (including dental surgery) or emergency treatment. Your doctor will decide whether you should continue using this medicine.

Stop using this medicine and check with your doctor immediately if 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).

This medicine may cause some people to become dizzy or drowsy. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.

What Are Reasons I Shouldn’t Take Prometrium?

Tell your healthcare provider if any of the following apply to you:

  • Hypersensitivity to its ingredients (allergic reaction) 
  • History of suspected breast cancer 
  • Liver dysfunction or disease 
  • Known or suspected pregnancy 
  • History of depression
  • History of probable dementia

What Other Medications Interact With Prometrium?

Medications that may interact with Prometrium include:

Before starting Prometrium, tell your healthcare provider about any other medicines you take, including over-the-counter (OTC), nonprescription products, vitamins, herbs, plant-based medicines, and other prescription drugs. Ask for a complete list of potential drug interactions.

What Medications Are Similar?

Other hormone-based medications similar to Prometrium include but are not limited to:

  • Aygestin (norethindrone) is a progestin-only oral contraceptive that suppresses ovulation to prevent pregnancy.
  • Crinone (progesterone) is a progesterone vaginal gel used to help treat women with a progesterone deficiency or secondary amenorrhea.
  • Depo-Provera (medroxyprogesterone): Medroxyprogesterone injection is a contraceptive used to prevent pregnancy.
  • Makena (hydroxyprogesterone injection) is a progestin injection used to reduce the risk of spontaneous preterm birth.
  • Provera (medroxyprogesterone) is a tablet form of medroxyprogesterone indicated to treat secondary amenorrhea and abnormal uterine bleeding due to hormonal imbalance. It can also be used to prevent endometrial hyperplasia.

This is a list of other hormonal drugs. It is NOT a list of drugs recommended to take with Prometrium. Talk to your pharmacist or healthcare provider if you have questions.

Frequently Asked Questions

  • Can I take Prometrium with food?

    Food may affect the way Prometrium works, but generally, it can be taken with or without food. However, if it causes an upset stomach, taking it with food is recommended.

  • My moods have been abnormal while on this medication. Is that normal?

    Mood swings are possible with the use of hormonal medications. However, if you experience any extreme mental changes that concern you, contact your healthcare provider immediately.

  • What is a common side effect of Prometrium?

    Common side effects of Prometrium include headache, dizziness, and drowsiness. Be sure to know how your body reacts to this medication before operating heavy machinery or doing anything that requires you to be alert.

  • What if I miss a dose?

    If you miss a dose, take it as soon as you think about it. If it is closer to the time for your next dose than the missed dose, take your regularly scheduled dose. Do not double up on doses.

How Can I Stay Healthy While Taking Prometrium?

To stay healthy while taking Prometrium, use your medication exactly as directed by a healthcare provider or pharmacist. Being adherent to the prescribed regimen is the only way to maximize the benefits of this medication. Routine follow-up appointments with your healthcare provider are necessary to ensure safe, effective use and to minimize the risk of unwanted side effects.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  8. DailyMed. Label: norethindrone tablet.

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