Medroxyprogesterone vs Estriol: side-by-side comparison
Medroxyprogesterone (Progestin) and Estriol (Estrogen (weak)) belong to different therapeutic classes and are rarely substitutes for each other. The comparison is useful when a single patient is weighing both options for adjacent or overlapping needs.
| Property | Medroxyprogesterone | Estriol |
|---|---|---|
| Therapeutic class | Progestin | Estrogen (weak) |
| CAS | 520-85-4 | 50-27-1 |
| ATC | G03DA02 | G03CA04 |
| Molecular weight | 344.49 g/mol | 288.39 g/mol |
| Brands with this active ingredient | 1 | 1 |
What they share
Medroxyprogesterone and Estriol share the common regulatory framework for prescription active ingredients, bioequivalence standards for generics, and pharmacist oversight. Beyond that, points in common are limited.
Key differences
Medroxyprogesterone acts by a different mechanism than Estriol, with indications that barely overlap. Comparing the two is useful when a clinician has mentioned both in the same context or the patient wants to understand why one was prescribed instead of the other.
Mechanisms compared
Medroxyprogesterone: MPA binds progesterone receptors and produces strong progestational effects: thickening cervical mucus, inhibiting ovulation, thinning the endometrium and reducing hot flashes. Estriol: Estriol binds estrogen receptors but with shorter receptor occupancy and weaker activation than estradiol, producing a 'weak' estrogenic effect.
Indications compared
Medroxyprogesterone: MPA is approved for amenorrhoea, abnormal uterine bleeding due to hormonal imbalance, prevention of endometrial hyperplasia in postmenopausal women receiving estrogen, and prevention of pregnancy (depot formulation). Estriol: Estriol vaginal preparations are approved for treatment and prevention of urogenital atrophy and recurrent urinary tract infections in postmenopausal women, and in some markets for vaginal preparation before pelvic surge…
Safety profile
Medroxyprogesterone: Common adverse effects of oral MPA include irregular bleeding, breast tenderness, mood changes, fluid retention and weight gain. Estriol: Vaginal estriol is well tolerated.
Frequently asked questions
Is Medroxyprogesterone better than Estriol? ▾
Medroxyprogesterone and Estriol are not "better or worse" — they treat different things. The sensible question is which fits your specific need.
Can Medroxyprogesterone and Estriol be combined? ▾
Whether they can be combined depends on the indications and the interaction profile of each. If both are in a single prescription, the prescriber has weighed it; in self-medication they should never be combined.
Do they have the same side-effect profile? ▾
No — they belong to different classes and have distinct side-effect profiles. Each has its own prescribing information.
Products with Medroxyprogesterone
Products with Estriol
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.