Viagra (sildenafil) started off as a rather disappointing treatment for angina but doctors began to notice that patients were very reluctant to stop taking it, even after surgery had dealt with any angina problems. One by one the Viagra users confessed that a wonderful thing had happened after Viagra: their sex life had dramatically improved.

Following this unexpected side effect Viagra was launched by Pfizer Pharmaceuticals in mid April 1998 in the US as a treatment for impotence and different degrees of erectile dysfunction. Within 14 days despite the high Viagra price, doctors were writing more than 110,000 Viagra scripts a week. In 14 weeks 2 million Viagra scripts had been written in the US alone and Viagra had become established as a new recreational drug in club culture world-wide.

Substitute viagra, free viagra, herbal viagra, cheap viagra, viagra sale online, natural viagra, viagra alternative - Viagra sales leapt and so did sales of every kind of aphrodisiac on the impotence market, all promising more for less.

After five years with 96% of the erectile dysfunction (ED) market to itself, Pfizer's Viagra isn't the only game in town for ED sufferers any more and is facing some stiff competition from cheap generics available online and from Levitra and Cialis treatments lauched in 2003 by Bayer & GlaxoSmithKline and Lilly & Icos respectively. Today the Viagra stampede has settled down, with a black market firmly established and accelerated by the Internet, allowing more than 70 million web surfers to purchase Viagra relatively easily and cheaply on the open market despite being classified as a prescription drug. In addition a large number of online pharmacies have sprung up offering Viagra without a medical consultation, at heavily discounted prices. And then there is fake Viagra, containing little or no real Viagra.

So does all this competition mean that Viagra will become cheaper. Many patients feel that they are being over charged for these pills and ask when and where cheaper treatments will come from?

While Pfizer is currently the only legal producer of the original branded Viagra, there are literally over a hundred companies making generic versions, such the popular Indian variety 'Kamagra'. However many people are quite rightfully reluctant to purchase generics which are illegally produced. As the only producers of the guaranteed branded product, Pfizer can maintain their high prices.

This is all set to change in 2010 when Pfizer's patent on Viagra expires and the market becomes a free for all. Other drug manufacturers will be allowed to produce sildenafil and be subject to the same regulations as Pfizer are. These are often cheaper than the original brand, and may be sold under the generic name or new brand names. A generic medicine is typically 20% to 80% less expensive than the brand-name original. The availability of lower-priced generic medicines brings down the price of originator drugs through market competition, producing even further savings to patients.

Effective competition between generic medicines and patent-expired original brands guarantees that customers can look forward to a lowering in price of branded pharmaceuticals.