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Medication guide

Micronized Progesterone

Protects the uterine lining when used with estrogen in the appropriate regimen.

Check the name, strength and form on your own prescription or package.

Brand
Prometrium
Guidance checked
2026-09-08

About this medication

  • Prometrium (progesterone) is used together with estrogen hormone therapy after menopause, in women who still have a uterus. It helps protect the lining of the uterus from overgrowth that estrogen alone can cause.

Protects the uterine lining when used with estrogen in the appropriate regimen.

How to use it

  • Swallow the capsule whole with a glass of water. Do not chew, crush, or pierce it.
  • Take this medicine with food, since food helps your body absorb it properly.
  • Take this medicine exactly as your healthcare professional tells you. The amount and how often you take it will be on your prescription label.
  • You may feel drowsy or a little dizzy a few hours after taking this medicine, especially if taken with a meal, so plan to take it at a time when this will not be a problem, such as before bed.

If you miss a dose

  • If you take one capsule at bedtime and forget it, take one capsule the next morning instead and then continue your normal schedule.
  • If you take capsules both in the morning and at bedtime and miss one of them, just skip that missed dose and continue with your regular schedule. Do not double up.

Follow the prescribed cycle. Swallow capsules whole; bedtime dosing can reduce the impact of drowsiness.

Pregnancy and breastfeeding

  • Do not use this medicine if you are pregnant or think you might be pregnant. Tell your healthcare professional right away if you become pregnant while taking it.
  • This medicine passes into breast milk and is not recommended while breastfeeding.

This menopausal product is not contraception or a self-directed pregnancy treatment.

Before you use it

  • Tell your healthcare professional if you have liver disease, a history of blood clots, breast cancer, unexplained vaginal bleeding, or an allergy to peanuts or soy, since the capsules contain a substance made from soy.
  • Tell your healthcare professional about all medicines you take, especially antifungal medicines, seizure medicines, or medicines for HIV.
  • Tell your healthcare professional if you are or might be pregnant, or are breastfeeding. This medicine should not be used during pregnancy.
  • Your healthcare professional should check your blood pressure, breasts, and pelvic area, and may recommend a mammogram before you start this medicine.

Important warnings

  • Long-term use of combined estrogen and progesterone therapy can raise the risk of heart attack, stroke, blood clots, and breast cancer. Use the lowest dose that controls your symptoms, for the shortest time needed.
  • This medicine may increase the risk of dementia in women 65 and older.
  • Get medical help right away for leg pain or swelling, sudden shortness of breath, chest pain, sudden severe headache, or sudden vision changes, since these can be signs of a blood clot or stroke.
  • Tell your healthcare professional right away about yellowing of the skin or eyes, dark urine, or severe stomach pain, which can be signs of a liver problem.
  • If you are allergic to peanuts, talk to the Care365 care team before using this medicine, since it contains a substance made from soy that may cause a reaction in people with peanut allergies.

Check ingredient allergies, including the referenced product’s soy/peanut warning, liver disease, bleeding and clotting/cancer history.

Possible side effects

  • Spotting or irregular bleeding between periods
  • Breast tenderness
  • Drowsiness or dizziness, especially a few hours after a dose
  • Bloating or stomach cramps
  • Nausea
  • Headache
  • Fatigue
  • Joint pain
  • Mood changes
  • Vaginal discharge or dryness

Dizziness, drowsiness and bleeding changes.

When to get help

When to get emergency help

  • Sudden chest pain or shortness of breath
  • Pain, redness, or swelling in one leg
  • Sudden, severe headache or sudden vision changes
  • Sudden weakness, numbness, or trouble speaking
  • Signs of a severe allergic reaction, such as swelling of the face or throat, hives, or difficulty breathing

When to contact a healthcare professional

  • Yellowing of the skin or eyes, dark urine, or severe stomach pain
  • Breast lumps or changes
  • Unusual or heavy vaginal bleeding
  • New or worsening migraine headaches
  • If you think you might be pregnant

Chest symptoms, neurological symptoms or unexplained bleeding needs assessment.

Other medicines and products

  • Take this medicine with food to help your body absorb it properly.
  • Tell the Care365 care team about other medicines and herbal products you use, including St. John's Wort, certain seizure medicines, and antifungal medicines, since these can change how well this medicine works.
  • Ask the Care365 care team before combining this medicine with other hormone products.

Review enzyme-inducing medicines and ciclosporin.

Missed doses, storage and accidental exposure

  • Store at room temperature, protected from light.
  • Keep out of reach of children and pets.
  • Return unused or expired capsules to your pharmacy for safe disposal.

Follow your own product’s missed-dose instructions. If you are unsure, ask the Care365 clinical team before taking an extra dose. Contraceptives, injections and modified-release medicines may need a specific plan.

Keep the original packaging and follow its storage, expiry and disposal instructions. Keep medicines away from children and pets. Ask about refrigeration, after-opening limits and safe sharps disposal when relevant.

For suspected overdose or accidental swallowing, contact poison control or urgent medical care promptly. Call emergency services for breathing difficulty, collapse or a seizure.

Key points to remember

  • Keep up with regular check-ups, breast exams, and mammograms while taking this medicine.
  • Use the lowest dose that controls your symptoms, for the shortest time your healthcare professional recommends.
  • Do not share this medicine with anyone else.

These practical points come from the Pharmasist patient handout for the same product monograph cited by this guide.

References and product information

Sources checked .

Sources checked 2026-09-08. Safety sections are highlights; consult the full product information for complete warnings and instructions.

Check the Canadian Drug Product Database by product name or DIN for current product information.

This is a plain-language guide, not the complete monograph. Match the name, strength and form on your package before using product-specific directions.

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