What is the recommended dose of Prometrium (progesterone) to induce menstruation in a patient with a normal reproductive system?

Dose of Prometrium to Induce Menstruation

For inducing menstruation in women with secondary amenorrhea (absence of periods after previously having them), Prometrium (micronized progesterone) should be given as 400 mg orally once daily at bedtime for 10 days. 1

FDA-Approved Dosing for Secondary Amenorrhea

• The FDA label for Prometrium explicitly states that for secondary amenorrhea, the dose is 400 mg taken as a single daily dose at bedtime for 10 days 1
• This is the only FDA-approved indication for using progesterone to induce menstruation 1
• The medication should be taken at bedtime because some women experience significant drowsiness, dizziness, blurred vision, or difficulty walking after taking Prometrium 1

Mechanism and Expected Outcome

• Progesterone withdrawal bleeding occurs after completing the 10-day course - menstruation typically begins within 2-7 days after stopping the medication 1
• This regimen works by providing exogenous progesterone to a primed endometrium (one that has been exposed to estrogen), then withdrawing it to trigger menstrual bleeding 1
• The patient must have adequate endogenous estrogen production for this approach to work effectively 1

Critical Clinical Considerations

Important contraindications to verify before prescribing: 1

• Prometrium contains peanut oil and is absolutely contraindicated in patients with peanut allergy 1
• Pregnancy must be ruled out before administration 1
• Avoid in patients with unusual vaginal bleeding of unknown cause, active liver disease, history of breast cancer or hormone-sensitive malignancies, or history of blood clots 1

Administration Instructions

• Take with a glass of water while standing at bedtime to reduce risk of choking if swallowing difficulty occurs 1
• Patients should be warned about potential drowsiness, dizziness, blurred vision, difficulty speaking, or abnormal walking that may occur 1
• If these neurological symptoms develop, patients should contact their healthcare provider immediately 1

Common Pitfalls to Avoid

Do not use lower doses - the FDA-approved dose is specifically 400 mg daily for 10 days for secondary amenorrhea, not the 200 mg dose used for endometrial protection in hormone replacement therapy 1

Ensure adequate estrogen priming - progesterone withdrawal bleeding will not occur if the endometrium has not been adequately primed by estrogen 1

This is not the same as emergency contraception or medical abortion - the research evidence discussing mifepristone (RU-486) and misoprostol for menstrual induction 2, 3, 4 refers to different medications and indications entirely, not to Prometrium for secondary amenorrhea 1