Tadalafil 2.5 mg is a low-dose medication commonly prescribed for the treatment of erectile dysfunction (ED) and sometimes for benign prostatic hyperplasia (BPH) symptoms. It works by inhibiting the phosphodiesterase-5 (PDE-5) enzyme, which helps relax blood vessels and improve blood flow to the penis, allowing a man to achieve and maintain an erection during sexual stimulation. The 2.5 mg strength is typically used as a daily continuous dose, helping provide long-lasting support for sexual function without the need to plan medication before intercourse. It may also help relieve urinary symptoms associated with prostate enlargement. Possible side effects include headache, back pain, flushing, nasal congestion, and indigestion, and it should be used under medical supervision.