What is the recommended progesterone (Progesterone) dosing regimen for irregular bleeding?

Progesterone Dosing Regimens for Irregular Bleeding

For irregular uterine bleeding, the recommended first-line progesterone regimen is oral medroxyprogesterone acetate 10 mg daily for 10-14 days per cycle, or micronized progesterone 200 mg daily for 12-14 days every 28 days. 1, 2

First-Line Treatment Options

Oral Progesterone Options:

• Medroxyprogesterone acetate (MPA): 10 mg daily for 10-14 days beginning on day 16 of each cycle 1, 3
• Micronized progesterone (MP): 200 mg daily for 12-14 days every 28 days 2

Alternative Delivery Methods:

• Vaginal progesterone: Micronized progesterone 200 mg daily for 12-14 days every 28 days 2
• Levonorgestrel-releasing IUD: Most effective option with up to 97% reduction in bleeding by 6 months 1, 3

Treatment Selection Algorithm

1. Determine if contraception is required:

   • If contraception needed: Consider levonorgestrel IUD (most effective) or combined hormonal contraceptives 1
   • If contraception not needed: Proceed with cyclic progesterone therapy 2

2. Determine patient preference regarding withdrawal bleeding:

   • If withdrawal bleeding acceptable: Use cyclic progesterone regimen
   • If withdrawal bleeding not desired: Use continuous combined regimen 2

3. Select appropriate regimen based on severity:

   • For mild-moderate bleeding: Oral/vaginal progesterone for 10-14 days per cycle
   • For severe bleeding: Consider levonorgestrel IUD or continuous combined therapy 1

Dosing Specifics by Scenario

For Cyclic Therapy (with withdrawal bleeding):

• Transdermal 17β-estradiol (if estrogen needed) administered continuously
• Add oral progesterone (MPA 10 mg daily or MP 200 mg daily) for 12-14 days every 28 days 2

For Continuous Therapy (avoiding withdrawal bleeding):

• Combined tablets containing estradiol and progestin administered continuously
• Example: 1-2 mg estradiol with 5 mg dydrogesterone or 2 mg dienogest 2

Efficacy Considerations

The levonorgestrel-releasing IUD is significantly more effective than oral medroxyprogesterone acetate for treating heavy menstrual bleeding:

• LNG-IUD reduces menstrual blood loss by median of 128.8 mL
• Oral MPA reduces menstrual blood loss by median of only 17.8 mL
• Success rates: 84.8% for LNG-IUD vs 22.2% for oral MPA 3

Common Side Effects and Management

• Breakthrough bleeding: Common with progestin-only methods, especially in first 3-6 months 4
• Amenorrhea: Occurs in approximately 50% of LNG-IUD users by 2 years (expected effect) 1
• Drowsiness: Can occur with oral micronized progesterone; administering at bedtime minimizes this effect 5
• Iron deficiency: Consider iron supplementation if bleeding is heavy or prolonged 1

Important Caveats

• Higher doses of medroxyprogesterone acetate (50 mg daily) may be needed for conditions like endometriosis but are not typically used for irregular bleeding alone 6
• Women with excessive bleeding unresponsive to medical therapy should undergo endometrial biopsy to rule out underlying pathology 1
• Consider structural causes of bleeding (polyps, fibroids) if response to hormonal therapy is inadequate 1
• Micronized progesterone may have fewer metabolic and vascular side effects compared to synthetic progestins 5