Finasteride can slow male pattern hair loss and improve hair growth in some men. It works by reducing the conversion of testosterone to dihydrotestosterone, or DHT, a hormone involved in the gradual shrinking of susceptible scalp hair follicles.[1]
Does it only prevent further loss?
No. In two controlled trials, men receiving finasteride had better hair counts, photographic assessments and self-reported hair appearance than those receiving placebo. The studies found both slower progression and increased growth over two years.[1]
That supports a benefit for male pattern hair loss, not a promise to restore any particular hairline. The FDA label specifically says effectiveness for recession at the temples has not been established.[2]
Photographs of a crown response, for example, cannot answer how much a deeply receded temple will change. The location and pattern of loss belong in the treatment discussion.[1][2]
Should a change be visible right away?
Hair treatment is assessed over months. FDA labeling says three months or more of use is generally needed before benefit is observed. The major clinical trials evaluated outcomes over one and two years.[1][2]
Consistent photographs can make those comparisons more useful: similar lighting, hair length and angle reduce the chance that styling or shadows determine the impression.
Is the benefit permanent after stopping?
The effect depends on continued treatment. The label reports reversal of the treatment effect within 12 months after withdrawal. A good response therefore comes with an ongoing decision about benefit, tolerability and preference.[2]
Sexual side effects, including changes in libido, erections and ejaculation, occurred in the clinical trials. FDA labeling also includes postmarketing reports of persistent sexual symptoms and psychiatric effects. Those risks belong alongside the potential hair benefit when deciding whether treatment fits.[2]
