Short answer: The Prometrium label has two schedules. To protect the uterine lining in postmenopausal women taking conjugated estrogens, it is 200 mg by mouth at bedtime for 12 days in a row per 28-day cycle. For secondary amenorrhea, it is 400 mg at bedtime for 10 days. Each dose is a single daily dose at bedtime because of possible dizziness and drowsiness.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Prometrium is approved for: Prometrium is approved to prevent endometrial hyperplasia (overgrowth of the uterine lining) in postmenopausal women with a uterus who take conjugated estrogens tablets, and to treat secondary amenorrhea, meaning periods that have stopped in women who previously had them (Indications and Usage). The capsules contain peanut oil.
Source
PROMETRIUM (progesterone, USP) Capsules 100 mg and 200 mg, prescribing information and Patient Information. Acertis Pharmaceuticals. DailyMed, version published July 27, 2026. DailyMed setid 1cf237ff-c4f8-4faa-a7aa-77599c856889
Prometrium is a capsule taken by mouth as a single daily dose at bedtime (Dosage and Administration).
It comes in 100 mg and 200 mg capsules of micronized progesterone in peanut oil (How Supplied and Patient Information).
For women who have trouble swallowing the capsules, the label says to take them with a glass of water while standing (Dosage and Administration).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Use | Dose | When | How long |
|---|---|---|---|
| Prevention of endometrial hyperplasia (postmenopausal woman with a uterus on daily conjugated estrogens) | 200 mg orally | Single daily dose at bedtime | 12 days sequentially per 28-day cycle |
| Treatment of secondary amenorrhea | 400 mg | Single daily dose at bedtime | 10 days |
For endometrial protection, Prometrium is used by a postmenopausal woman with a uterus who is receiving daily conjugated estrogens tablets.
In amenorrhea studies, 10 days of 300 mg per day produced withdrawal bleeding within 7 days of the last dose in 80% of women vs 10% on placebo; 300 or 400 mg in a dosing study produced it in 73.8% and 76.8%.
If feasible, Prometrium is stopped at least 4 to 6 weeks before surgery linked to a higher risk of blood clots, or during prolonged immobilization.
Caution is advised when driving or operating machinery, as Prometrium may cause short-lived dizziness and drowsiness.
Capsules are stored at 25 C (77 F), with excursions from 15 to 30 C, protected from excessive moisture.
The Prometrium label gives no missed-dose rule. Neither the prescribing information nor the Patient Information says what to do if a capsule is missed.
More on this: missed a dose of Prometrium.
In Dose Track you set up Prometrium as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.