A 5-alpha reductase inhibitor called finasteride is used to treat symptomatic benign prostatic hyperplasia (BPH), a condition that affects the majority of men over 50. In men with BPH, finasteride has been proven to raise and sustain the maximum urine flow rate, albeit fewer than 50% of men experience improvement despite a smaller prostate. A 50% decrease in serum PSA concentrations can be anticipated in a typical patient receiving finasteride treatment for BPH (>= 6 months); however, particular persons may see different PSA declines. Even when prostate cancer is present, serum PSA concentrations may decrease throughout treatment. Values should be increased for comparison with normal ranges in men who are not receiving treatment if doctors employ serum PSA concentrations as an assist in the identification of prostate cancer in men taking finasteride. Even though the number is within the normal range for untreated men, any increase from the starting point may indicate the presence of prostate cancer. No adjustments to PSA results appear to be required if doctors want to utilize percent free PSA (free to total PSA ratio) as a marker because finasteride does not appreciably lower the value. 1 The FDA warned medical professionals of the potential risk of an increased incidence of high-grade prostate cancer in patients receiving finasteride or dutasteride treatment in June 2011 after reviewing two sizable, randomized controlled trials, the Prostate Cancer Prevention Trial (PCPT) and the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial. The PCPT trial’s findings revealed that men who received finasteride had a 26 percent lower overall chance of being diagnosed with prostate cancer compared to those who received a placebo (p 0.0001); however, the risk reduction was only applicable to tumors with a Gleason score (GS) of less than 6. Finasteride increased the risk of GS 8–10 prostate cancer compared to placebo (1.8 percent vs. 1.1 percent , respectively). 2 3 The efficacy of finasteride in treating bitemporal recession has not been established, but it has been shown to be effective for mild to severe hair loss of the vertex and anterior mid-scalp area. The FDA authorized finasteride (Proscar) for the treatment of BPH in June 1992. In December 1997, the FDA authorized Propecia, an additional oral finasteride dose form, for the management of male pattern baldness (i.e., androgenetic alopecia). Finasteride is also being tested as an alternate medication for the treatment of hirsutism.