Vidalista’s active ingredient, Tadalafil, works by inhibiting the PDE5 enzyme, which normally breaks down cyclic guanosine monophosphate (cGMP), a molecule that helps relax the smooth muscles of the penis. When the PDE5 enzyme is inhibited, the levels of cGMP rise, which in turn enhances blood flow to the penis during sexual arousal. This allows men with ED to achieve and sustain an erection when sexually stimulated. It is important to note that Vidalista will only work when there is sexual arousal, and it does not cause spontaneous erections.
https://www.genericday.com/vidalista.html