Kamagra Oral Jelly 100 mg contains sildenafil citrate, a type 5 Phosphodiesterase (PDE5) inhibitor. Sildenafil in Kamagra oral jelly acts on the erectile tissue of the penis to increase blood flow to the penis, which is needed to cause an erection. During sexual stimulation, nitric oxide is released into the erectile tissue of the penis, which activates the enzyme granulate cycle. This enzyme increases the levels of a chemical called cyclic Guanosine monophosphate (cGMP), which relaxes the blood vessels in the penis and allows blood to fill the spongy erectile tissues to cause an erection. Another enzyme called Phosphodiesterase type 5 (PDE5) breaks down cGMP preventing blood flow to the penis and causing you to lose an erection.