Finasteride is one of two FDA-approved treatments for hair loss, and comes under a class of drugs called type 2 5α-reductase inhibitors. These drugs inhibit the enzyme type 2 5α-reductase which catalyzes the conversion of testosterone to dihydrotestosterone. The overactivity of this enzyme causes an increase in dihydrotestosterone which is associated with the emergence of androgenetic alopecia. Finasteride is probably the most well-studied hair loss treatment, and comes in both oral and topical forms, although only the oral form is FDA-approved.
- The in vitro evidence shows that finasteride is an effective 5α-reductase inhibitor which is beneficial for people with male pattern baldness.
- The in vivo evidence shows that topical finasteride may have protective effects against androgenetic alopecia. A 2% finasteride solution applied to an alopecia-like mouse resulted in an increase in follicle density as well as an enhanced number of growing (anagen) hairs
- 1mg/day of oral finasteride has been found to be an effective dose in male pattern hair loss, with men showing a 68.4% reduction in serum dihydrotestosterone (DHT) levels after one year. Furthermore, treating men with androgenetic alopecia with 0.2 – 5 mg/day of finasteride for 4-6 weeks can reduce DHT levels by up to 65% in the scalp.
- 1% topical finasteride has also been found to be as effective as 1 mg oral finasteride at treating hair loss, increasing total hair counts, and decreasing scalp and plasma levels of DHT, however the number of studies are still limited, so further studies should be completed to support this.
- Some people may experience sexual side effects from taking finasteride, so it is important to consult your doctor to potentially change the dose if you start to experience these.
- Finasteride is an easy-to-use product with high rates of success, and as such, may be a good choice for some hair loss sufferers.