Progesterone Dose Modification
Do not cut your 200mg progesterone capsule in half or attempt to drain it—the standard recommended dose for endometrial protection is 200mg daily for 12-14 days per cycle, and altering the capsule compromises its formulation and effectiveness. 1, 2
Standard Dosing Requirements
The FDA-approved dosing for micronized progesterone is clear and should not be modified:
- 200mg daily at bedtime for 12-14 days per 28-day cycle when used with estrogen for endometrial protection 2
- This dose is specifically designed to prevent endometrial hyperplasia and cancer in women receiving estrogen therapy 1, 3
- The capsule formulation is engineered for optimal absorption and should be swallowed whole with water while standing 2
Route of Administration Considerations
Both vaginal and rectal administration of 200mg progesterone are acceptable alternatives to oral dosing, and you may continue using either route without dose modification. 1
Vaginal Administration
- 200mg micronized progesterone vaginally for 12-14 days every 28 days is equivalent to oral dosing for endometrial protection 1
- Vaginal administration achieves preferential uterine uptake through direct vagina-to-uterus transport, providing adequate endometrial protection despite lower systemic progesterone levels 4
- This route typically produces fewer systemic side effects (drowsiness, dizziness) compared to oral administration 4, 5
Rectal Administration
- While less commonly discussed in guidelines, rectal administration has been studied as an alternative route 6
- The 200mg dose remains appropriate regardless of administration route 1
Why You Cannot Reduce the Dose
Reducing progesterone below 200mg daily compromises endometrial protection and significantly increases your risk of endometrial hyperplasia and cancer. 1, 3
- Sequential regimens specifically require 200mg of micronized progesterone for 12-14 days every 28 days to provide adequate endometrial protection when combined with estrogen 1
- Alternative lower-dose continuous regimens exist (such as 100mg for 25 days per month), but these require different treatment protocols and medical supervision 5
- Cutting capsules or draining contents destroys the micronized formulation, which is essential for adequate absorption 5
If You're Experiencing Side Effects
If you're attempting dose reduction due to side effects:
- Take the 200mg capsule at bedtime to minimize drowsiness and dizziness, which are the primary side effects of oral micronized progesterone 2, 5
- Switch to vaginal administration if oral side effects are intolerable—this provides equivalent endometrial protection with significantly fewer systemic effects 1, 4
- Vaginal progesterone produces lower plasma levels but maintains adequate uterine tissue concentrations through first-uterine-pass effect 4
Critical Safety Warning
Never use estrogen therapy without adequate progesterone supplementation if you have an intact uterus—this dramatically increases endometrial cancer risk. 3, 7