Sildenafil, also translated sildenafil, is a research and development of drug treatment of cardiovascular disease, accidentally invented the treatment of erectile dysfunction drugs, usually with its commercial name (China registered name , Taiwan and Hong Kong up Name ) is well known. But relative to the brand name of sildenafil in China, common name " " is more widely used in the impact is greater. Since Pfizer patented Sildenafil, so the company manufactured, is the only legitimate to the market as the main ingredient sildenafil drug.