Pfizer has launched a website to sell its erectile dysfunction blockbuster Viagra, in a bid to stop the sale of counterfeit pills from fake online pharmacies.

The drugs giant says that the site, which is powered by CVS/pharmacy and accessible through, offers men in the USA with ED an opportunity to purchase Viagra (sildenafil) online with a valid prescription "from a trusted source". Victor Clavelli, marketing group leader at Pfizer's primary care business unit, noted that there are almost 24 million searches a year for Viagra online and "by offering men with ED convenient access and a legitimate alternative…our hope is that Pfizer will help rein in the distribution of fake ED products".

Matthew Bassiur, vice president of Pfizer Global Security, said that "we have seen counterfeit medicines manufactured in filthy and deplorable conditions, yet some people do not realise the risks that this poses to their health and safety, our top priority". He noted that samples of counterfeit Viagra tested in the company's labs have contained pesticides, wallboard, commercial paint and printer ink.

In 2011, Pfizer Global Security evaluated 22 websites appearing in the top search results for the phrase “buy Viagra” and conducted chemical analysis of the pills advertised as Pfizer’s Viagra that were ordered from these outlets. The study found that about 80% of these pills were counterfeit, and while the fake Viagra pills contained sildenafil, the amount was only 30%-50% of what was advertised.

The initiative will be closely watched by drugmakers, and indeed pharmacies and insurance firms, as the highly-unusual step of selling lifestyle treatments direct to patients may be seen by companies as an attractive proposition.