Erectile dysfunction has been a major issue for a number of men for too long. It is one of those medical conditions that do not result in any consequences for the body, but the consequences this condition can have on the psyche of the man are just ego-destroying. The simple fact is that our modern society seems to revolve around sex. Sex has permeated every aspect of our lives and there is now more pressure than ever before to lead a sex life of proportions that would kill a rhino. All of this leads to extreme pressure on a man to be able to last for hours, to be ready to go whenever and as many times as necessary. Having sex has become the most important thing in the world. And all of this is very difficult on a man who is suffering from ED, being unable to achieve an erection and lead an active sex life.
For a long, long time, this has been an issue with no solution. The only thing you could do was try some natural remedies and early medications that did very little, if any. However, in 1998, we got Viagra, the first ED medication developed by a major company and approved by medical agencies from all over the world, including FDA. In the following few years, we also got first Levitra and then Cialis.
All three of these FDA-approved medications work in a very similar way. They inhibit the PDE5, which is an enzyme which affects another chemical known as cGMP, which is in turn responsible for relaxing the smooth muscles in the blood vessels that lead the blood into the penis tissue. As the levels of PDE5 get lower, the levels of cGMP get bigger, the blood vessels relax and blood gets into the penis, thus resulting in erection. As far as this goes, these three medications are pretty much the same. However, there are some differences.
First of all, there are more PDEs in the body, not just PDE5. Other PDEs have influence on other systems, organs and processes in the body and the 
advantage of Cialis over Viagra and Levitra is that it affects other PDEs to a much lesser extent, thus minimizing the side effects.
There is an even more important difference between these three and that is how long their effects last. Viagra users can feel its beneficial effects for up to 4 hours. With Levitra this is increased somewhat, but Cialis is an absolute champion here, lasting for up to 36 hours. This makes Cialis an absolute winner among the three, making it easier than ever before to take the pill and not worry when you are going to have sex. In fact, there is now Cialis available that is taken once a day, just like any other medication, which is perfect as it virtually makes the ED go away. No more planning, no more worrying if you have taken the pill at the right moment.