Sildenafil is the main ingredient in Kamagra tablets. This tablet is used for the treatment of ED. The tablet is taken orally with water 30 to 40 minutes before. The effect of this tablet lasts for 4 to 5 hours, so a kamagra effervescent tablet should not be taken more than 1 time in 24 hours.drkamagra.com where you will find all the details of this tablet.