Tamsulosin is primarily used to treat benign prostatic hyperplasia (BPH) and is not specifically indicated for erectile dysfunction (ED), but it may have some benefits for ED in certain cases. Tamsulosin, marketed as Flomax, is an alpha-blocker primarily prescribed for managing the symptoms of BPH, a condition characterized by an enlarged prostate. It works by relaxing the muscles in the bladder and prostate, which helps improve urine flow and reduce symptoms associated with BPH.