A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. These small differences affect the way each medication works, such as how quickly it takes effect and wears off, and the possible side effects. This product is available in the following dosage forms: Tablet Suspension There is a problem with information submitted for this request. It lasts 4 to 5 hours, or longer if you have mild to moderate ED. You can take it in a small dose daily or in a larger dose as needed. Its effects often last for 4 to 5 hours.Generic Viagra (sildenafil) is an alternative to the branded Viagra drug that can be used for treating erectile dysfunction (ED). It’s now sold by many manufacturers, including online. If you’re holding out for a generic version of branded Viagra, you won’t have to wait much longer. Teva Pharmaceuticals plans to release its generic of the “little blue pill” as early as. Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. It is also used to treat pulmonary arterial hypertension, a serious heart and lung condition. This drug is more popular than comparable drugs. It is available in generic and brand versions.