Finasteride blocks the hormone that drives male pattern hair loss. It's the most-researched, most-effective oral medication in the field — and it's the maintenance therapy that turns surgical results into lifetime results.
Male pattern baldness is caused by dihydrotestosterone (DHT) — a derivative of testosterone that miniaturises hair follicles in genetically susceptible men. Finasteride is a 5-alpha-reductase inhibitor: it blocks the enzyme that converts testosterone to DHT, dropping scalp DHT levels by roughly 70%.
The result, in clinical trials: roughly two-thirds of men on 1mg/day daily finasteride see hair growth or maintenance over five years. Roughly 90% see no further loss. The remaining 10% continue to lose despite treatment.
Finasteride does not regrow hair from completely bald scalp — it preserves what's there and modestly thickens follicles that haven't yet died. The earlier you start, the more you preserve.
Finasteride's side-effect profile is real but small. In clinical trials, sexual side effects (decreased libido, erectile dysfunction, decreased ejaculate volume) occurred in roughly 1–2% of users — slightly above the placebo rate. Most who experience side effects find they resolve within weeks of stopping the medication.
A smaller subset of patients report persistent post-finasteride symptoms (PFS) that don't resolve on discontinuation. The medical community is divided on causation; the symptoms are real but the prevalence and underlying mechanism remain debated. We discuss this honestly with every patient considering finasteride.
Topical finasteride (applied to the scalp) is an alternative for patients concerned about systemic exposure — it delivers the same scalp-DHT reduction with much lower blood levels of the drug. Most current research suggests topical formulations have a substantially lower side-effect rate.
Finasteride is contraindicated in women of reproductive age (it can cause birth defects). For post-menopausal women with androgenetic alopecia, finasteride is sometimes prescribed off-label.
Hair transplants move follicles that are already DHT-resistant from the back of the head to the front and crown. Those follicles will grow for life. But the surrounding native hair — the hair that wasn't transplanted — is still susceptible to DHT and will continue to thin if untreated.
The result, without finasteride: the transplanted hair stays, the surrounding hair recedes around it, and within a few years you have an obvious result floating in a thinning frame. The result, with finasteride: the surrounding hair is preserved, the transplanted hair integrates seamlessly, and the result holds for decades.
We don't require finasteride to operate — but we do discuss it honestly because it's the difference between maintaining the result for a decade versus a lifetime.
Whether finasteride is right for you depends on your stage, your tolerance for the side-effect risk profile, and whether you're planning surgery. Discuss it with Dr. Jones in your consultation.