Finasteride is generally recognized as the most effective therapy for treating male pattern baldness. Increased hair on the scalp can be seen within three months of starting treatment and longer-term studies have demonstrated increased hair on the scalp at 24 and 48 months with continued use. In one study, Finasteride was effective at stopping hair loss in 83% of men compared to 28% for the placebo group. Effectiveness only persists as long as the drug is taken. Finasteride typically works better to prevent further hair loss than to regrow lost hair.