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Drug profile
Finasteride
5α-reductase inhibitor that reduces dihydrotestosterone (DHT) synthesis.
Why this drug?
Finasteride was developed for BPH and serendipitously found to promote hair regrowth, leading to a second approved indication for androgenetic alopecia—a classic mechanistic repurposing story.
Known risks
- Sexual dysfunction
- Depression (reported, debated incidence)
- PSA reduction (masking prostate cancer screening)
- Contraindicated in pregnancy (teratogenic)
Evidence behind this
Confidence score95%
Signal strength: HighLevel 1 (RCT + regulatory approval)
Evidence grade
Approved
Reduced prostate volume, improved symptom scores vs placebo.
Mechanism
DHT reduction decreases prostate volume and improves urinary flow.
clinical trialfda labelPhase III
Authoritative sources
AI-generated summary
Generated March 15, 2026Last verified June 24, 2026
Finasteride is FDA-approved for BPH with Phase III PLESS trial evidence demonstrating symptom and volume benefits. 5α-reductase mechanism directly addresses disease pathophysiology.
Source papers
- McConnell JD et al., NEJM 1993
This summary is AI-assisted and human-reviewed. It does not constitute medical advice. Always consult authoritative sources and qualified professionals.