The active ingredient in the Kamagra 100 mg oral jelly is sildenafil, which is used to treat men suffering from erectile dysfunction and impotence. The effect of this medicine lasts for 4-5 hours so men should take this medicine 30 minutes before sexual intercourse. The effect of this medicine lasts for 4-5 hours so men should take this medicine only once a day. You should not eat heavy food and not consume alcohol while taking this medicine. It is important to consult your doctor while taking this medicine.