sildenafil is the active ingredient in Cenforce 100 mg tablet, a medication used to treat erectile dysfunction and impotence. This jelly works to relax the muscles and improve blood flow to the penile tissues in men. Take this half an hour before sexual activity. This can be taken either before or after a meal. This has additional side effects, so take this medication as prescribed by your physician. This jelly's effects last for 6 hours.