FDA approved three drugs for the treatment of impotence: Cialis, Viagra and Levitra. All the three drugs work in the manner to increase the blood flow into the penis by relaxing the penile artery. These drugs are very much helpful to increase the erection. It is the effectiveness of the medicines in relation to the time they stay effective that separates them.

The effectiveness of viagra remains up to 4 hours and up to 5 hours for Levitra, but the effectiveness of cialis remains up to 36 hours and that's why it is called "Weekend Drug" and the second largest selling ED drug in the world.

Now Viagra, Levitra or Cialis have presence in more than 80 countries and the World Wide Web make it available everywhere. Now online offer cheaper prices of impotence pills as well as you can get free consultation. Now days to buy cialis one doesn't have to go to the chemist but it's just a click away on internet.

Today more than 50 millions of men are suffering from erectile dysfunction in US alone. The research on erectile dysfunction shows that 30% men in the world are suffering from erectile dysfunction and 50% men over the age of 40 are severely.

Viagra and Cialis have made the good presence in the world for erectile dysfunction on the other hand Levitra is also gaining popularity over a short span of time. Most of the men started with the Viagra but they ended with cialis just because it is more effective and the effect of drug remains for 36 hours. Always consult to a healthcare practitioner before taking any erectile dysfunction drugs. Cialis can be taken without food or after having good diet.

Levitra is on the other hand a good erectile dysfunction drugs, but Levitra has fewer side effects compare to Viagra and Cialis. Levitra is very good for those men who have side effects with Viagra or Cialis.