The history of Viagra dates back to 1996, when it was patented and on March 27, 1998 was approved for sale in case of erectile dysfunction by the FDA (Food and Drug Administration) in U.S, thus becoming the first ever oral treatment for erectile dysfunction in the U.S. The origin of Viagra came from the drug Sildenafil that was synthesized by some pharmaceutical chemists who were working at Pfizer's research facility in Sandwich, Kent, England. Initially the drug was studied upon to treat hypertension and angina pectoris (ischaemic heart disease). The first ever clinical trials conducted in Swansea under the observation of Ian Oterloh and he observed that it didn't have much effect on angina; rather it could induce remarkable penile erections. Pfizer thus decided to market and promote the drug for erectile dysfunction instead of angina. So the drug was approved for people suffering from erectile dysfunction. It became a big success soon with the annual sales exceeding $1 billion in between 1999-2001.

Albert Wood and Peter Dunn were portrayed as the inventors of this drug by The British press but this is a claim that has been rejected by Pfizer itself. Their names are found on the patent manufacturing application drug; however Pfizer claims that their names are mentioned only for convenience.

Although Sildenafil was made available only when prescribed by a registered doctor, it was directly advertised to the consumers on the U.S TV and the soccer star Pele and former U.S senator Bob Dole endorsed it for the first time. You can often find a simple web questionnaire on thousands of sites offering Viagra for sale along with an online consultation. After the name of Viagra became famous, many aphrodisiacs have also started calling themselves herbal Viagra. They are being promoted and endorsed as blue pills that imitate the color and shape of Pfizer's product. Informally, Viagra is also known as "the Blue Pill", "Vitamin V" and by many other nick names.

The sale of Viagra recorded 92 percent sale in the global market in 2000 and it was prescribed as pills for erectile dysfunction all over the world. The global share of Viagra had plunged to 50% by 2007 due to several factors. The entry of Levitra and Cialis were the main reasons as well as the entry of other clones and counterfeits and reports of loss of vision in people who were taking PDE5 inhibitors. In February 2007, there was an announcement that counter sales of Viagra would be trialed upon by the Boots the Chemist in the stores of the Manchester, England. Men of the age group between 30 and 65 were declared to be eligible to purchase four tablets of Viagra but only after they consult with a pharmacist.

The worldwide patents of Pfizer on Sildenafil citrate are to expire in 2011-2013. In 2000 the use of PDE5 inhibitors to treat impotence and erectile dysfunction was invalidated by the patent held by Pfizer in the UK because of obviousness. However this decision was appealed against and was upheld in 2002.

Nowadays, you hear a lot of online Viagra stories from time to time and the myth continues.