“The little blue pill” known as Viagra is the world’s most popular erectile dysfunction medicine. It’s also the source of many inaccurate medical myths. Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. When a man is sexually stimulated, his body's normal response is to increase blood flow to his penis to produce an erection. Viagra is used to treat problems relating to male sexual function, particularly problems concerning the ability to achieve and maintain an erection. Learn how to take Viagra safely to treat erectile dysfunction. Swallow a 50 mg dose of Viagra 30-60 minutes before sex. Pfizer to lose patent of drug Viagra, Indian companies gear up with copycat versions: Pfizer's patent for the formulation of Viagra, used to treat impotence in men, ends in the US in 2020. Learn more about Viagra, including its uses, dosage, side effects, and how to get it. Find out how sildenafil treats erection problems and pulmonary hypertension and how to take it. NHS medicines information on sildenafil – what it's used for, side effects, dosage and who can take it. Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Below, we'll explain the origin story of Viagra, what this boner-benefitting pill can do, the benefits of Viagra for men, and the potential side effects of taking it. Viagra relaxes muscles found in the walls of blood vessels and increases blood flow to particular areas of the body. Viagra is used to treat erectile dysfunction (impotence) in men. Find patient medical information for Sildenafil (Viagra, Revatio) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.