Kamagra 100 mg is a drug used to treat weak erection and erectile dysfunction in men. This drug contains an ingredient called sildenafil citrate which is taken to increase blood flow to the penile tissues of men. This medicine should be taken only once a day. This drug helps men to know strong erection during intercourse. It is important to consult a doctor before taking this medicine. This drug is for men over 18 years of age and should not be taken by women or children. The effect of this drug is seen in about 30 minutes. The effect of this drug lasts from 4 to 6 hours.