The 5α-reductase inhibitor finasteride blocks the conversion of testosterone to dihydrotestosterone(DHT), the androgen responsible for androgen- etic alopecia in genetically predisposed men.

The purpose of this study was to determine the efficacy of finaster- ide treatment according to the type of androgenetic alopecia in Korea.

196 patients with finasteride(1.25mg/day) were registered in this study and 68 patients were followed over 8 months. Efficacy was evaluated by globa1 photographs, investigator assessment of clinical change,and patients' self assessment via self administered hair growth questionnaire.

Patients' self-assessment demonstrated that finasteride treatment slowed hair loss, increased hair growth, and improved appearance of hair. These improvements were corroborated by objective assessments after 4 months of treatment. Adverse effects such as sexual dysfunction were minimal.

Oral finasteride 1.25mg/day slowed the progression of hair loss and increased hair growth in clinical tria1s of men with androgenetic alopecia over 8 months. With its generally good tolerability profile, finasteride is a new approach to the management of this condition, for which treatment options are few.