Finasteride works by inhibiting the enzyme 5α-reductase type II, which converts testosterone into dihydrotestosterone (DHT)—a hormone that contributes to prostate enlargement and hair follicle miniaturization :contentReference[oaicite:1]{index=1}. In men with enlarged prostates (BPH), finasteride helps shrink prostate volume, improve urinary flow, and lower the risks of urinary retention and prostate surgery :contentReference[oaicite:2]{index=2}. In the treatment of male pattern baldness (androgenetic alopecia), it reduces scalp DHT levels, helping to slow hair loss and promote regrowth—especially in the crown area—with effects noticeable as early as six months but requiring ongoing use to maintain results :contentReference[oaicite:3]{index=3}.

Key Benefits

• Relieves urinary symptoms, reduces prostate size, and lowers surgical risk in BPH :contentReference[oaicite:4]{index=4}
• Slows male pattern hair loss and supports hair regrowth with sustained use :contentReference[oaicite:5]{index=5}
• Lowers systemic and scalp DHT levels by approximately 65–70% :contentReference[oaicite:6]{index=6}