Penegra is a member of the class of drugs known as PDE5 inhibitors. It functions by causing your penis' blood vessels to relax. Depending on your doctor's recommendation, you can take Penegra with or without food. You should take the tablet 30 to 60 minutes before engaging in sexual activity. Only when you are sexually stimulated can this medication help you get and sustain an erection. If you want speedy results, don't take extra pills. If you have low blood pressure, recently had a heart attack or stroke, or serious heart or liver problems, do not use this medication.