t was discovered by a group of chemicals pharmaceuticals company Pfizer, in its research center in Sandwich (near Dover, England).

Although its scientific name is sildenafil citrate, better known by the trade name Viagra. His says his business name was inspired probably by the word "viāghra" which in Sanskrit means "tiger" by the monuments of the animals on their erect penises into the gates of the temples.

It was originally designed for use in hypertension and angina pectoris. The first trials with this drug were made ​​in Morriston Hospital in Swansea (Wales).

During the initial studies it was thought that the drug had little effect on angina, but what s that it could induce remarkable erections. That's why Pfizer decided to market it for erectile dysfunction, rather than for angina.

He thus became the first pill approved to treat erectile dysfunction in the United States. Immediately became a bestseller, reaching between 1999 and 2001 annual revenue for Pfizer over a billion dollars.