“Finasteride regrows hair.”
In men with male pattern hair loss, finasteride regrows a modest amount of hair, while men on placebo keep losing it.
If you have male pattern hair loss, finasteride is one of the few treatments with solid evidence: expect to keep more hair and regrow some, not to get back a full head. The benefit lasts only as long as you keep taking it.
Take photos of your hairline and crown in the same light before you start, and compare them with your prescriber after about a year of daily use.
Safety note: Finasteride raises the chance of erection problems, by about 1 extra man in 82 in pooled trials, and depression and suicidal thoughts have been reported since approval. People who are or may be pregnant should not handle crushed or broken tablets because the drug can harm a male fetus. It lowers PSA, so tell your doctor you take it before prostate screening.
Talk to a healthcare professional if: your hair loss is sudden, patchy, painful or inflamed, or you notice sexual side effects or low mood while taking finasteride.
Many randomized trials in men with male pattern hair loss show finasteride increases hair counts and improves how hair looks compared with placebo, which is why confidence is strong. It is Mostly true rather than True because regrowth is modest, it does not restore a full head of hair, it is proven only for pattern hair loss in men, and the gains reverse within a year of stopping.
In men with male pattern hair loss, finasteride regrows a modest amount of hair, while men on placebo keep losing it. In two large trials, men taking 1 mg a day had about 107 more hairs than placebo in a 1-inch circle on the crown after 1 year and 138 more after 2 years, from a starting count of about 876. In pooled trials, about 1 extra man in every 3 or 4 treated saw his hair as improved over 2 years or more.
Benefit is judged over months, and the drug's label says the effect reverses within 12 months of stopping. The large trials enrolled men aged 18 to 41, and the evidence does not cover women, scarring hair loss or sudden patchy loss, which need a different diagnosis. A review of placebo-controlled trials found finasteride, minoxidil and low-level laser therapy all beat placebo for male pattern hair loss.
- Mella JM, Perret MC, Manzotti M, Catalano HN, Guyatt G. Efficacy and safety of finasteride therapy for androgenetic alopecia: a systematic review. Archives of Dermatology. 2010;146(10):1141-1150. DOI: 10.1001/archdermatol.2010.256. PMID: 20956649
- Kaufman KD, Olsen EA, Whiting D, et al.; Finasteride Male Pattern Hair Loss Study Group. Finasteride in the treatment of men with androgenetic alopecia. Journal of the American Academy of Dermatology. 1998;39(4 Pt 1):578-589. DOI: 10.1016/S0190-9622(98)70007-6. PMID: 9777765
- Adil A, Godwin M. The effectiveness of treatments for androgenetic alopecia: a systematic review and meta-analysis. Journal of the American Academy of Dermatology. 2017;77(1):136-141.e5. DOI: 10.1016/j.jaad.2017.02.054. PMID: 28396101
- Organon. PROPECIA (finasteride) tablets prescribing information, as reproduced by Drugs.com