Finasteride, which specifically inhibits the 5α-reductase type 2 (SRD5A2), suppresses the conversion of testosterone into dihydrotestosterone (DHT) and is more effective in reducing the periurethral area, prostate gland size, and urinary obstructive symptoms in patients with BPH [16,17]. Here, SRD5A2 is linked to benign prostatic hyperplasia.