So How does it work?
T o understand how Viagra works it is necessary to first understand the mechanism of erection of the penis. This involves the release of NO during sexual stimulation, the released NO activates an enzyme called guanylate cyclase which causes an increase in cyclic guanosine monophosphate (cGMP) levels which, in turn allows for smooth muscle relaxation and the inflow of blood.
The sildenafil citrate works simply by inhibiting an enzyme
which is responsible for the degradation of cGMP. Hence, when Viagra is taken
release in NO results in high levels cGMP as the inhibitory enzyme is itself
being inhibited, there is smooth muscle relaxation and an inflow of blood.