Sildenafil is a PDE5 Inhibitor that is FDA-approved for the treatment of erectile dysfunction (ED).
Sildenafil is the generic form of Viagra. Generic medications are required by the FDA to be bioequivalent to the brand medication, meaning that they act the same way in the body and have the same active ingredients. Generic medications also tend to be less expensive than the brand medications and most medications sold in the U.S. are generic.
