Kamagra pills are used to treat impotence in men. The drug contains sildenafil citrate, which works to relax the muscles by increasing blood flow to the penile arteries. If the effect of this medicine is seen in 30-40 minutes, you can take this medicine 1 hour before sexual activity. This medicine can be taken before or after food. The effect of this medicine lasts for about 36 hours. This medication should only be used by men aged 18 or older as advised by their doctor.