From Mayo Clinic to your inbox Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Be prepared for questions such as these: What other health concerns or chronic conditions do you have? When a man is sexually stimulated, his body’s normal response is to increase blood flow to his penis to produce an erection. What, if anything, seems to improve your symptoms? Take sildenafil exactly as directed. Sildenafil Viagra is used to treat erectile dysfunction impotence; inability to get or keep an erection in men.It’s a prescription drug that’s used in adult males* with ED. With ED, you have trouble getting or keeping an erection. To find out more about how Viagra is used . VIAGRA (sildenafil citrate) is prescription medicine used to treat erectile dysfunction (ED). VIAGRA is not for women or children. Please see Full Prescribing Information . Oral medications are a successful erectile dysfunction treatment for many men. They include: Sildenafil (Viagra) Tadalafil (Adcirca, Cialis) Vardenafil (Levitra, .