Sildenafil citrate is a PDE5 inhibitor that works by relaxing the smooth muscle in the walls of blood vessels, increasing blood flow to narrow areas of the body, including the penis. For creation to occur, the penis must be filled with blood. This makes more serotonin available to the brain. Cenforce 100 is meant to be taken once every 24 hours. For best results, take the pill 1-2 hours before...