Proscar, generically known as finasteride, is a medication primarily used in the treatment of benign prostatic hyperplasia (BPH), which is an enlarged prostate. It functions by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), a hormone that plays a key role in the development of enlarged prostate. By reducing the levels of DHT, Proscar helps in decreasing the size of the enlarged prostate, thereby alleviating symptoms such as difficulty in urination, decreased urine flow, and nighttime urination urgency. It is important to note that Proscar is not approved for the prevention of prostate cancer and may slightly increase the risk of developing a very serious form of prostate cancer. It is available in tablet form and is usually taken once a day, with or without food, as prescribed by a healthcare provider.