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CompoundIQ publishes research summaries for informational and educational purposes only. Nothing on this site constitutes medical advice, diagnosis, or treatment recommendations. Always consult a licensed healthcare provider. Many compounds listed are research chemicals not approved for human use.
Finasteride
Also known as: Propecia, Proscar
Finasteride is a selective type II 5-alpha reductase inhibitor approved for male pattern hair loss (1 mg, Propecia) and benign prostatic hyperplasia (5 mg, Proscar). It reduces scalp DHT levels by approximately 60-70% and is one of only two FDA-approved oral medications for androgenetic alopecia. It has decades of clinical data supporting its efficacy.
Risk Level
Medium RiskDifficulty
Beginner| CAS Number | 98319-26-7 |
| Molecular Formula | C23H36N2O2 |
| Class | Other |
| Category | Hair Loss Compounds |
Mechanism of Action
Finasteride competitively inhibits type II 5-alpha reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT) in the prostate, scalp, and liver. By reducing serum DHT by ~70% and scalp DHT by ~60%, it slows and can reverse miniaturization of androgen-sensitive hair follicles. It does not affect type I 5-AR, leaving some DHT production intact. Terminal hair count increases typically peak at 1-2 years of use.
Dosing Research
Standard dose: 1 mg/day orally (Propecia). Some protocols use 0.5 mg/day or 1 mg every other day with similar efficacy and potentially fewer side effects. Proscar 5 mg tablets are often quartered for cost savings. Effects take 3-6 months to become visible and 12 months for full evaluation. Must be taken continuously; hair loss resumes within 6-12 months of discontinuation.
Side Effects & Risks
Sexual side effects in 2-4% of users: decreased libido, erectile dysfunction, reduced ejaculate volume. Usually resolve upon discontinuation. 'Post-finasteride syndrome' (persistent sexual/neurological symptoms) is reported but controversial and not well-established in controlled studies. Gynecomastia rare (<1%). Depression and brain fog reported anecdotally. Not for use by women of childbearing potential (teratogenic).
Research Studies
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Disclaimer
CompoundIQ publishes research summaries for informational and educational purposes only. Nothing on this site constitutes medical advice, diagnosis, or treatment recommendations. Always consult a licensed healthcare provider. Many compounds listed are research chemicals not approved for human use.