Kamagra is for people who are suffering from erectile dysfunction or impotency. The main active component is sildenafil citrate in this medicine, which relaxes the muscles and helps increase blood flow to the penis. This medicine is taken 30 to 60 minutes before the sexual session. The effect of this medicine lasts for 4-5 hours. It can be taken with or without food but it is better if taken on an empty stomach. Women should not use this medicine.