Finasteride is a medication that inhibits 5α‑reductase, the enzyme that converts testosterone into dihydrotestosterone (DHT). Elevated levels of DHT are the main driver of androgenetic alopecia in men. By reducing DHT in the scalp, finasteride slows or stops the miniaturisation of hair follicles and can promote regrowth.
### Evidence from clinical studies
* **Efficacy:** Large clinical trials have shown that finasteride 1 mg daily prevents further hair loss in the vast majority of men and leads to visible regrowth in a significant proportion. Long‑term studies (over five years) demonstrate sustained benefits with continued use.
* **Timeline:** Most men notice stabilisation after three to six months of daily treatment. Visible thickening typically appears between six and twelve months. Finasteride must be taken continuously to maintain the effect; stopping treatment will allow DHT to rise and hair loss to resume.
* **Topical formulations:** Finasteride can also be applied to the scalp. Topical finasteride lowers DHT locally with less systemic exposure, which may reduce the risk of side effects. Evidence suggests that topical finasteride has similar efficacy to oral finasteride for many men.
### Who finasteride is for
* **Men only:** Finasteride is prescribed to men. It is not recommended for women, especially those who are pregnant or may become pregnant, because reducing DHT can cause fetal developmental abnormalities.
* **Early to moderate hair loss:** Finasteride works best when hair follicles are still present. It cannot restore hair once follicles have disappeared entirely.
* **Combination therapy:** Combining finasteride with minoxidil often produces better results than either treatment alone because they target different mechanisms.
### Safety and side effects
Finasteride is generally well tolerated. A small percentage of men report reduced libido, erectile dysfunction or reduced ejaculate volume. These side effects are usually mild and reversible upon discontinuation. Rarely, some men experience mood changes. Topical finasteride formulations may lower the risk of systemic side effects. If you experience bothersome or persistent adverse effects, speak to your prescriber.
### LEO’s finasteride options
LEO offers both oral finasteride 1 mg tablets and a topical solution containing finasteride 0.01 % combined with minoxidil 6 % and azelaic acid 2 %. Our topical solution uses the natural, alcohol‑free TrichoSol base to minimise irritation and is applied with precision applicators or the LEO Scalp Roller for targeted delivery.
### Summary
Finasteride is an evidence‑based treatment for male pattern hair loss. By reducing DHT, it slows or stops follicle miniaturisation and can support regrowth. Results typically begin after three to six months and improve over the first year. Treatment must continue to maintain benefits. Finasteride is prescribed to men only and may be used orally or topically; combining it with minoxidil provides a synergistic approach.