What is Cialis (tadalafil)?
Cialis is in a class of medications known as PDE-5 inhibitors, which are used to treat cases of male impotence. Elli Lilly and Icos are currently marketing Cialis in the U.S., UK, EU , and countries around the world.

How does Cialis (tadalafil) work?
Cialis acts in the same way as Viagra, by blocking an enzyme called phosphodiesterase-5, or PDE-5. Cialis is more targeted than Viagra which results in fewer sides effects and lower dosage. Cialis helps the smooth muscles in the penis relax and widen, which allows for more blood to enter. As a result, you gain erections faster and easier with Cialis.

How well does Cialis (tadalafil) work?
Cialis is approved in authorized markets for the treatment of mild to severe ED at both 10 and 20 mg Cialis doses. When you buy Cialis, the labels in each of these markets indicate that the product should be taken prior to anticipated sexual activity and without regard to food. Just like Viagra, sexual stimulation is needed for Cialis to work. According to the European label, the efficacy of Cialis may persist up to 24 hours after the pill is taken. In Australia and United States the label indicates efficacy up to 36 hours after dosing.

Who can not use Cialis?
Cialis is not for everyone. Men taking any form of nitrates (often used to control anginal chest pain) should never take Cialis, as the combination may cause an unsafe drop in blood pressure. Men taking medicines called "alpha blockers" (sometimes prescribed for prostate problems or high blood pressure), with exception of Flomax® (tamsulosin HCl) 0.4 mg once-daily, should not take Cialis. This side effects from this combination could cause a significant drop in blood pressure.