The 5 Alpha-Reductase Isozyme Family: A Review of Basic Biology and Their Role in Human Diseases

Table 2

Comparison between finasteride and dutasteride (referenced in text).

	Finasteride	Dutasteride
Family	Steroidal 5α-RI (4-azasteroid)	Steroidal 5α-RI (4-azasteroid)
IC50 for 5α-R1, 2 and 3 (nM)	360, 69, 17.4	7, 6, 0.33
FDA-approved clinical uses	Male androgenic alopecia; Benign prostatic enlargement	Benign prostatic enlargement
Clinical dose	1 mg daily for male androgenic alopecia; 5 mg daily for benign prostatic enlargement	0.5 mg daily
Half-life (T 1/2)	6–8 hours	5 weeks
Suppression of DHT	↓Serum DHT by 71%	↓Serum DHT by 95%
	↓Intraprostatic DHT by 85%	↓Intraprostatic DHT by 97–99%