PDE-5 is inhibited by Sildenafil Cenforce. It increases blood flow to the penis with sexual stimulation by relaxing the blood vessels in the penis. Pay close attention to the instructions on your prescription label, and ask your pharmacist or doctor to clarify any parts you don't understand. Follow the directions on sildenafil precisely. You can take the Cenforce with or without food. It must be taken exactly as prescribed by your physician. Each person has a different time frame for working, but it often takes 30 to 60 minutes. Before taking it, let your doctor know if you have any of these or any other health issues. If this medication causes you to feel lightheaded, you should not drive.