Why Is Generic Viagra So Much Cheaper?

Before trying generic Viagra, you need to know how it works. Firstly, you should know that it is classified as a PDE5 inhibitor, and here’s why. When erection happens, the brain sends a signal to the penis, and that releases a special chemical called nitric oxide. It is a chemical messenger needed for stimulating the cGMP enzyme, whose acronym stands for “cyclic guanosine monophosphate”.