The preferred medical treatment for many men with symptomatic benign prostatic hyperplasia is either an alpha-adrenergic-receptor antagonist (alpha-blocker), which reduces smooth-muscle tone in the prostate, and bladder neck, or a 5α-reductase inhibitor, which reduces prostate volume by inducing epithelial atrophy. These drugs have side effects including:-dizziness, fatigue, hypotension, headache, insomnia, gynecomastia, and retrograde ejaculation.