Finasteride is primarily used to treat male pattern hair loss and benign prostatic hyperplasia (BPH). In cases of hair loss, it works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), a hormone that shrinks hair follicles, thereby promoting hair regrowth and preventing further loss. For BPH, it helps reduce the size of the enlarged prostate, alleviating symptoms such as difficulty urinating, weak urine flow, and frequent urination. It is often prescribed as a long-term treatment and requires consistent use to maintain its effects. Patients should consult a healthcare provider to assess suitability and monitor potential side effects.