Finasteride Reduces Serum PSA to a Similar Extent at 1 mg and 5 mg Daily Doses

In a study published in 2007, D'Amico and Roehrborn conducted a randomized, placebo-controlled, double-blind trial across 18 US centers to investigate the effect of finasteride, a type 2 5α-reductase inhibitor, on serum prostate-specific antigen (PSA) levels. The study included 355 men aged 40-60 years with male-pattern alopecia. After 2 weeks of placebo treatment, participants were randomly assigned to either placebo or finasteride 1 mg daily for 48 weeks. The results showed that serum PSA levels decreased by a median of 40% in men aged 40-49 years and 50% in men aged 50-60 years who were actively treated with finasteride. The authors concluded that 48 weeks of 1 mg finasteride daily has a similar effect on PSA levels as 1-3 years of 5 mg finasteride daily. They suggested that further studies are needed to understand the effect after 48 weeks.