Viagra: the facts behind the hysteria

Sildenafil citrate as a newly discovered substance was patented by Pfizer in the beginning of 90s and approved by FDA in 1998. During the following decade and a half Viagra was available only in form of drug produced by the original manufacturer, due to the validity of patent. As of recent

Viagra has become an icon of the pharmaceutical industry as mentioned here. You could say that it is the so-called celebrity pill that is constantly making noise in the world. Having appeared on the market in 1998, Viagra has since completely changed the world. A large number of men have been able to overcome their sexual problems and regain their younger years.