Finasteride (Propecia) stops and partially reverses hair loss
The most-studied AGA drug. Reduces DHT by ~70%. Stable or improved density in 80-90% of users over years. Sexual side effects 1-4%, mostly reversible.
What the evidence says
The studies, decoded
Decades of RCT data (Kaufman 1998 onward, Roberts 1999, Mella 2010 meta-analysis): 1mg oral daily produces stable or modestly improved hair density in 80-90% of men with androgenetic alopecia at 5-year follow-up. The 'PFS' (post-finasteride syndrome) literature exists and is contested — large pharmacovigilance data places persistent sexual side effects at 0.5-2%, while published RCT incidence is 1-4% acute. The substrate of the controversy is real but the magnitude is much smaller than online forums imply.
How it actually works
Mechanism
Inhibits 5-alpha-reductase type II, reducing conversion of testosterone to DHT by ~65-70%. Follicles in the AGA-sensitive zones are no longer miniaturized.
What to actually expect
Realistic outcome
1mg/day oral, indefinitely. Effects visible at 4-6 months, full plateau by 12-18 months. Stopping = loss within 6-12 months. Side effect rate is meaningful but small; if it's you, stop.
If this is overhyped — what is not
Better alternatives
Topical finasteride (lower systemic absorption, smaller side-effect risk, similar local efficacy — Lee 2018). Dutasteride is stronger but with worse side-effect profile. Minoxidil stacks well. Hair transplant is permanent but surgery.
Sources
Citations
- Long-term (5-year) multinational experience with finasteride 1 mg in the treatment of men with androgenetic alopeciaKaufman et al., 1998, J Am Acad Dermatol
- Topical vs oral finasteride for AGALee et al., 2018, J Drugs Dermatol
Minoxidil 5% topical regrows hair
About 60% partial regrowth, 80% slowed progression at 12 months. OTC, well-tolerated. Lifetime commitment — stop and the gain reverts.
MaybeDerma roller (microneedling) regrows hair
Real adjunct effect — adding microneedling to minoxidil roughly doubles density gain in trials. Standalone effect is modest. 1.5mm roller, once a week, not daily.
MaybeRosemary oil regrows hair like minoxidil
One real RCT showed comparable density gain to minoxidil 2% at six months. Smaller effect than minoxidil 5%, but a real signal — and topical, cheap, no Rx.