Anastrozole vs Progesterone
A side-by-side research comparison of Anastrozole and Progesterone across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | Anastrozole | Progesterone |
|---|---|---|
| Full name | Anastrozole (Arimidex) | Micronized Progesterone (Prometrium) |
| Category | Hormone Replacement | Hormone Replacement |
| Status | FDA-approved prescription | FDA Approved |
| Mechanism | Selectively and reversibly inhibits aromatase (CYP19A1), the enzyme that converts androgens to estrogens. Reduces circulating estradiol levels without affecting other steroid pathways. | Agonizes progesterone receptors and GABA-A receptors (via allopregnanolone metabolite). Inhibits 5-alpha reductase, opposes estrogen proliferative effects, and promotes myelination in neural tissue. |
| Molecular weight | 293.37 Da | 314.46 Da |
| Half-life | ~46.8 hours | ~16-18 hours (oral micronized) |
| Bioavailability | ~80-85% oral | ~10% oral (first-pass); ~100% topical/vaginal |
| Typical dose | 0.25-0.5 mg | 100-200 mg oral or 20-40 mg topical |
| Frequency | 2-3x per week | Nightly (oral) or daily (topical) |
| Route | Oral tablet | Oral capsule, topical cream, or vaginal |
Anastrozole reported benefits
- Estrogen control
- Reduced water retention
- Prevention of gynecomastia
- Maintained testosterone ratio
- Improved body composition
Progesterone reported benefits
- Enhanced deep sleep (GABA modulation)
- Neuroprotection
- Estrogen opposition
- Reduced anxiety
- DHT reduction (5AR inhibition)
- Cardiovascular protection
Related comparisons
Research and educational reference only. Not medical advice.