Erectile dysfunction or ED, often called impotence affects many men.
Viagra can help many men who have ED get and keep an erection when they become sexually stimulated, either physically or visually.

Cialis acts in the same way as Viagra, by blocking an enzyme called phosphodiesterase-5, or PDE-5. This 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.

Levitra works by helping to relax the blood vessels in the penis, allowing blood to flow into the penis causing an erection. Levitra will not give a man an erection spontaneously, it will only help a man to get an erection if he is sexually stimulated. Also now (NEW From Bayer) Levitra Orodispersible is available, a new formulation which disolves in the mouth and produces results in 20 minutes.