Sildenafil (Viagra) is a tablet that's taken by mouth for erectile dysfunction (ED) in adults. It works as a phosphodiesterase-5 (PDE5) inhibitor to help people get an erection or keep an erection that lasts for sex. You only take a dosage when you need it (usually about an hour, or anywhere from 30 minutes to 4 hours, before sex). Take sildenafil (Viagra) no more than once a day. Otherwise. Viagra (sildenafil) is a brand-name prescription drug that’s used to treat erectile dysfunction (ED). Learn about side effects, warnings, dosage, and more. Find patient medical information for Sildenafil (Viagra, Revatio) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Determine whether Viagra is the right choice for your symptomsViagra 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. Viagra (sildenafil) is used to treat erectile dysfunction or impotence in men. Includes Viagra side effects, interactions and indications. Sildenafil is used to treat erectile dysfunction in adult men or pulmonary arterial hypertension in adults and children, depending on the brand or formulation. Includes sildenafil side effects, interactions, and indications. El sildenafil, o sildenafilo, es un medicamento que sirve para tratar la disfunción eréctil en hombres y la hipertensión pulmonar, tanto en hombres como en mujeres, y se comercializa con los nombres de Viagra, Lerk o Patrex. Vea para qué sirve, cómo funciona, cómo tomar, dosis y efectos. “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. Sildenafil, sold under the brand name Viagra among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension. [4][8] It is also sometimes used off-label for the treatment of certain symptoms in secondary Raynaud's phenomenon. [9] It is unclear if it is effective for treating sexual dysfunction in females. [8] It can be taken orally (swallowed by mouth. Learn more about Viagra, including its uses, interactions and risks, dosage, side effects, and how to get it.