Viagra started a revolution. Before this wonder blue pill came out on March 27,1998, millions of men worldwide suffered in silence over their erectile dysfunction (ED) condition as it was considered shameful and a blow to their manliness. Today, Viagra has greatly diminished this social taboo and weaved itself into the public's lexicon, raking up serious money along the way.

In the first year alone, sales of Viagra brought in over a billion dollars for its manufacturer Pfizer Inc. Viagra also opened the doors for competitors to the newly minted ED market. Bayer and GlaxoSmithKline came out with Levitra on August 20, 2003, followed closely by Eli Lilly and ICOS with Cialis on November 1, 2003. All 3 drugs are the leaders in the ED market with billions in dollars made yearly, and are, obviously, each other's main rivals. They set themselves apart from their competitors by their medical effectiveness (Levitra can result in the fastest effects from 25 minute to an hour and lasts for about 5 hours, while Cialis lasts the longest), price ( Cialis is slightly cheaper than the other two), and brand recognition (Viagra, the pioneer, wins hands down).

Riding on the waves of success of these major brands are the generic versions. As they do not have brand names attached to them nor have to incur the high costs of aggressive marketing, these generic ED pills like Zydena, Silagra, and Kamagra (which contain the same active ingredient Sildenafil or Tadalafil found in Viagra and Cialis) cost significantly cheaper. Many men, especially those in less wealthy countries, request for them instead of the branded ED pills. Not to mention, when the patents of the ED drugs expire, with Viagra being the first in 2012, the generics drug market will definitely pounce in to have a bigger share of the $160 billion ED market pie, which will not be tough, considering the generic drugs market is already worth millions.

Also benefiting from the "Viagra effect" is the alternative herbal medicine market. Men who do not like the artificial chemicals in the prescription pills or are unable to take them due to medical reasons (eg. heart problems) would look to natural eastern alternatives like Horny Goat Weed from China, Yohimbe from West Africa, Korean (panax) ginseng etc. These herbs are generally marketed as "Herbal Viagra" to the western world and come in pill forms as well to rival the ED giants. However, besides Yohimbe, most of these sexual herbs have not received certification from the US Food and Drug Administration (FDA).

As always, something that achieves success quickly will have its fair share of backlashes. Viagra, Cialis and Levitra all were hard hit by reports of causing cases of vision and hearing loss in 2005 and the FDA has since issued warnings to their labels. Annual sales of all 3 ED drugs are gradually declining, and the market dynamics are projected to remain flat. The outlook for potential new drugs to break into the market is gloomy, as the market may have already peaked. The proliferation of imitation drugs further jeopardizes sales. What with patent expiry coming up soon and competition from the generics as mentioned earlier, it certainly looks like the glory days of the blockbuster ED drugs are coming to an end.