Cyclic Progesterone Timing for Abnormal Uterine Bleeding
For abnormal uterine bleeding due to ovulatory dysfunction, start cyclic progesterone on day 12 of the menstrual cycle and continue through day 25 (or for 12-14 consecutive days in the luteal phase). This timing provides endometrial protection while maintaining cycle regularity 1.
Dosing Algorithm by Clinical Scenario
For Ovulatory Dysfunction (Anovulatory Bleeding)
- Start day 12-25 of cycle: Use 200 mg progesterone orally at bedtime for 12 consecutive days per 28-day cycle 1
- This regimen is FDA-approved for prevention of endometrial hyperplasia and has demonstrated 94% reduction in hyperplasia risk compared to unopposed estrogen 1
Alternative timing based on recent evidence: Starting progesterone on day 16-25 (10-day protocol) may provide superior cycle regulation compared to day 11-25 (15-day protocol), with faster achievement of bleeding control—typically within 3 cycles 2. However, the FDA-labeled 12-day regimen starting day 14 remains the standard 1.
For Secondary Amenorrhea
- Any day: Give 400 mg progesterone orally at bedtime for 10 consecutive days 1
- 80% of women will experience withdrawal bleeding within 7 days of completing therapy 1
Key Evidence Considerations
The FDA labeling provides the clearest guidance: day 14-25 dosing (12 days total) when used with estrogen for endometrial protection 1. For isolated ovulatory dysfunction without concurrent estrogen therapy, the same luteal phase timing applies—starting around day 12-14 to mimic natural progesterone secretion.
Critical distinction: Luteal phase dosing (days 12-25) is significantly less effective than longer 21-day regimens (day 5-26) for reducing measured menstrual blood loss 3. However, the 21-day regimen has lower patient acceptability and higher discontinuation rates. For acute bleeding control requiring maximum efficacy, consider the extended regimen; for cycle regulation and long-term management, use the standard luteal phase timing.
Administration Details
- Take at bedtime due to significant drowsiness, dizziness, and potential transient neurologic symptoms (blurred vision, difficulty speaking, abnormal gait) 1
- Standing position with water if swallowing difficulty occurs 1
- Contraindication: Peanut allergy (capsules contain peanut oil) 1
Common Pitfalls
Avoid starting too early in the cycle (before day 12) as this may interfere with ovulation in women with intermittent ovulatory function. Avoid starting too late (after day 16) as this shortens the duration of endometrial protection and may reduce efficacy for cycle regulation 2.
Do not use luteal-phase-only dosing if the patient is on unopposed estrogen therapy—this requires the full 12-day sequential regimen to prevent hyperplasia 1.