Can 200 mg of progesterone (a hormone) stop or delay a menstrual period?

Progesterone at 200 mg Does Not Stop Menstrual Periods—It Induces Withdrawal Bleeding

Progesterone at 200 mg daily does not stop menstrual periods; rather, it supports endometrial development and, when withdrawn after 12-14 days, triggers predictable withdrawal bleeding that mimics a menstrual period. 1, 2

Mechanism of Action: Why Progesterone Causes Rather Than Stops Bleeding

• Progesterone stabilizes and matures the endometrium that has been primed by estrogen, preventing spontaneous breakthrough bleeding during administration 1
• Withdrawal of progesterone after 12-14 days causes organized endometrial shedding, producing a predictable "period" 1, 2
• This is the physiologic basis for sequential hormone therapy regimens used in hormone replacement therapy 2

Standard Dosing Regimens That Produce Regular Bleeding

• Micronized progesterone 100-200 mg daily for 12-14 days every 28 days is the recommended sequential regimen that produces monthly withdrawal bleeding 1, 2
• After completing the 12-14 day course, bleeding typically occurs within 2-7 days of stopping progesterone 2
• This regimen is specifically designed to mimic natural menstrual cycles and provide endometrial protection 1

Clinical Context: When Progesterone Is Used

In Hormone Replacement Therapy

• Progesterone must be added to estrogen therapy to prevent endometrial hyperplasia and cancer 1, 2
• The 200 mg dose for 12-14 days monthly is standard for endometrial protection while maintaining regular bleeding patterns 1, 2

In Pubertal Induction

• Progesterone is only added after 2-3 years of estrogen-only therapy or when breakthrough bleeding occurs 1
• The purpose is to establish regular withdrawal bleeding patterns, not to stop bleeding 1

Important Distinction: Continuous vs Sequential Regimens

• Sequential regimens (200 mg for 12-14 days) produce monthly bleeding by design 1, 2
• Continuous daily regimens (100 mg daily without breaks) may eventually produce amenorrhea in some women, but this is a different dosing strategy 2
• The question specifically asks about 200 mg, which aligns with sequential rather than continuous dosing 1, 2

Common Pitfall: Confusing Progesterone Effects

• Do not confuse progesterone with mifepristone (a progesterone antagonist), which can induce bleeding through a completely different mechanism by disrupting progesterone's endometrial effects 3, 4
• Do not confuse oral micronized progesterone with 17-alpha-hydroxyprogesterone caproate (17P), which is used for preterm birth prevention at 250 mg IM weekly and has different indications 2, 5

Pharmacokinetics Supporting This Effect

• Oral micronized progesterone 200 mg produces peak plasma concentrations at 2 hours and maintains elevated levels of biologically active metabolites for at least 12 hours 6
• This sustained exposure is sufficient to maintain endometrial stability during administration 6
• Upon withdrawal, the rapid decline in progesterone levels triggers endometrial breakdown and bleeding 6

Clinical Bottom Line

If the goal is to stop or delay a period, 200 mg progesterone given in the standard sequential fashion (12-14 days monthly) will not achieve this—it will actually induce a predictable withdrawal bleed when stopped. 1, 2 To potentially suppress menstruation, continuous daily progesterone without breaks would be required, though even this does not reliably stop periods in all women 2