Not Recommended Progestins (MPA)
What Is MPA?
Section titled “What Is MPA?”Medroxyprogesterone acetate (MPA) is a synthetic progestin, commonly known by brand names:
- Provera (oral, 5-10 mg)
- Depo-Provera (injection, 150 mg/3 months)
MPA was widely used in postmenopausal hormone therapy but large clinical trials (WHI study) revealed significant risks.
Why It Is Not Recommended
Section titled “Why It Is Not Recommended”1. Significantly Increases VTE Risk
Section titled “1. Significantly Increases VTE Risk”Compared to natural progesterone, MPA significantly increases venous thromboembolism (VTE) risk [2] [3] :
- MPA + estrogen VTE risk: RR approximately 2.0-2.5
- Natural progesterone + estrogen VTE risk: RR approximately 1.0 (no significant increase)
2. Adverse Metabolic Effects
Section titled “2. Adverse Metabolic Effects”- May reduce HDL (“good” cholesterol)
- Unfavorable effects on insulin resistance
- Weight gain
3. Safer Alternatives Exist
Section titled “3. Safer Alternatives Exist”- Micronized progesterone: Natural/bioidentical, VTE risk neutral
- Dydrogesterone: Better oral bioavailability, superior safety data
- Hydroxyprogesterone caproate: Injectable option
If You Are Currently Using MPA
Section titled “If You Are Currently Using MPA”Exception Circumstances
Section titled “Exception Circumstances”In resource-limited settings where MPA may be the only available progestogen:
- Use the lowest possible dose
- Intensify VTE risk factor monitoring
- Prioritize not smoking and weight management
- Switch to natural progesterone or dydrogesterone as soon as available