Table 2: Comparison between finasteride and dutasteride (referenced in text).


FamilySteroidal 5α-RI (4-azasteroid)Steroidal 5α-RI (4-azasteroid)

IC50 for 5α-R1, 2 and 3 (nM)360, 69, 17.47, 6, 0.33

FDA-approved clinical usesMale androgenic alopecia
Benign prostatic enlargement
Benign prostatic enlargement

Clinical dose1 mg daily for male androgenic alopecia
5 mg daily for benign prostatic enlargement
0.5 mg daily

Half-life (T 1/2)6–8 hours5 weeks

Suppression of DHTSerum DHT by 71%Serum DHT by 95%

Intraprostatic DHT by 85%Intraprostatic DHT by 97–99%