How many days is medroxyprogesterone acetate (MPA) given to induce withdrawal bleeding in patients with Polycystic Ovary Syndrome (PCOS)?

Medroxyprogesterone Acetate Duration for Withdrawal Bleeding in PCOS

For inducing withdrawal bleeding in PCOS patients, medroxyprogesterone acetate (MPA) should be given for 10-14 days, with the standard regimen being 10 mg daily for 10 days. 1, 2, 3

Standard Dosing Protocol

The evidence consistently supports a 10-14 day duration for progestin administration when inducing withdrawal bleeding in PCOS:

• 10 mg MPA daily for 10 days is the most commonly studied and recommended regimen for inducing withdrawal bleeding in oligomenorrheic women with PCOS 3
• The 12-14 day duration provides maximal endometrial maturation and adequate protection against hyperplasia 4
• Research specifically in PCOS patients used MPA 5 mg twice daily (10 mg total) for 14 days with successful withdrawal bleeding 5

Alternative Regimen for Micronized Progesterone

If using oral micronized progesterone instead of MPA:

• 100 mg in the morning and 200 mg before bedtime for 7 days has been validated specifically in PCOS patients to induce withdrawal bleeding without altering androgen levels 6
• This shorter 7-day course is effective with micronized progesterone due to its different pharmacokinetics compared to synthetic progestins 6

Clinical Considerations Specific to PCOS

Critical timing issue: Blood samples for diagnostic hormonal evaluation should be obtained before progestogen administration, as MPA significantly decreases testosterone, androstenedione, and LH levels within days of treatment 7, 3

• Androgen and LH levels decline significantly after MPA-induced withdrawal bleeding and remain suppressed for 2-3 weeks 7
• This suppression masks the biochemical findings characteristic of PCOS (elevated LH:FSH ratio, elevated androgens) 3

Practical Algorithm for PCOS Patients

For withdrawal bleeding induction:

1. Use MPA 10 mg daily for 10 days as first-line 3
2. Alternative: MPA 10 mg daily for 14 days if using as part of ongoing cyclic therapy 1, 2
3. Alternative: Micronized progesterone 300 mg daily (100 mg AM, 200 mg PM) for 7 days if preferred 6

For ongoing cycle regulation in PCOS:

• A recent study demonstrated that 10-day MPA administration (days 16-25 of cycle) was superior to 15-day administration (days 11-25) for achieving regular cycles and stopping abnormal bleeding 8
• Three cycles of the 10-day protocol were sufficient to achieve cessation of abnormal bleeding 8

Common Pitfall to Avoid

Never obtain diagnostic hormone levels immediately after progestogen-induced withdrawal bleeding — wait at least 3-4 weeks for androgen and gonadotropin levels to return to baseline PCOS patterns, or obtain samples before any progestogen administration 7, 3