Progesterone Dosing in Postmenopausal Women for Hormone Replacement Therapy
For postmenopausal women requiring progesterone as part of hormone replacement therapy, the recommended dosage is 200 mg of oral progesterone daily at bedtime for 12 continuous days per 28-day cycle when used in combination with estrogen. 1, 2
Progesterone Regimen Options
FDA-Approved Regimen for Endometrial Protection
- Continuous-cyclic regimen: 200 mg oral progesterone daily at bedtime for 12 continuous days per 28-day cycle in combination with estrogen 1, 2
Alternative Regimens Based on Clinical Practice
- Continuous-combined regimen: 100 mg oral progesterone daily for 25 days per month 1, 3, 4
- Sequential regimen: 300 mg oral progesterone daily from day 16 to day 25 of the cycle 3
Rationale for Progesterone Use
Progesterone is essential in postmenopausal women taking estrogen who have an intact uterus to:
- Prevent endometrial hyperplasia (which occurs in 64% of women taking estrogen alone vs. only 6% with combined therapy) 2
- Reduce the risk of endometrial cancer 1, 2
Administration Considerations
- Progesterone should be taken at bedtime due to potential drowsiness 1, 2, 4
- Some women may experience extreme dizziness during initial therapy 2
- In rare cases, symptoms may include blurred vision, difficulty speaking or walking 2
- The medication contains peanut oil and should not be used in women with peanut allergies 2
Monitoring and Follow-up
- Clinical review should be performed every 3-6 months initially, then annually 1
- Report any persistent or recurring abnormal vaginal bleeding for appropriate diagnostic evaluation 1, 2
- Regular assessment of symptom control and compliance is necessary 1
Side Effects and Risks
Common Side Effects
- Headaches
- Breast tenderness
- Irregular vaginal bleeding or spotting (typically resolves within 3-6 months)
- Nausea and vomiting
- Drowsiness (reason for bedtime administration)
Serious Risks
- Potential increased risk of dementia in women over 65 2
- Possible increased risk of blood clots, stroke, and heart attack 2
Important Considerations
- Use the lowest effective dose for the shortest duration consistent with treatment goals 1
- Micronized progesterone is preferred over synthetic progestins (like medroxyprogesterone acetate) by some clinicians due to potentially fewer metabolic and vascular side effects 4
- The 200 mg dose has been shown to provide complete endometrial protection in clinical trials 2, 4
Contraindications
Progesterone should not be used in women with:
- Unusual vaginal bleeding
- Current or history of breast cancer or other hormone-sensitive cancers
- Current or history of blood clots, stroke, or heart attack
- Current or history of liver problems
- Known peanut allergies (for oral progesterone capsules containing peanut oil) 2