Finasteride is used to shrink an enlarged prostate (benign prostatic hyperplasia or BPH) in adult men. It may be used alone or taken in combination with other medications to reduce symptoms of BPH and may also reduce the need for surgery. Finasteride may improve symptoms of BPH and provide benefits such as decreased urge to urinate, better urine flow with less straining, less of a feeling that the bladder is not completely emptied, and decreased nighttime urination. This medication works by decreasing the amount of a natural body hormone (DHT) that causes growth of the prostate. Finasteride is not approved for prevention of prostate cancer. It may slightly increase the risk of developing a very serious form of prostate cancer. Talk to your doctor about the benefits and risks. Women and children should not use this medication.