Numerous clinical studies have shown that the use of Cialis gives the best results and improves erection in men in almost all cases. Cialis has a very strong and quick action as totally new components and technologies are used in its formula. The action of the drug starts quickly and lasts about 2 days. This result is not broken by any competitors including sexual generic Viagra and Levitra. So today cialis is one of the best and successful drugs for the treatment of impotence.