Kamagra 100 mg, which contains sildenafil citrate as its active ingredient, primarily works by inhibiting the enzyme phosphodiesterase type 5 (PDE5). This inhibition allows for increased levels of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the blood vessels, particularly in the corpus cavernosum of the penis. Nitric oxide (NO) plays a crucial role in the mechanism of action of Kamagra 100 mg (sildenafil). Normally, sexual stimulation causes the release of nitric oxide in the penis. Nitric oxide activates an enzyme called guanylate cyclase, which results in increased levels of cGMP. cGMP relaxes the smooth muscles and allows blood to flow into the corpus cavernosum, causing an erection. PDE5 normally breaks down cGMP, which terminates the erection. By inhibiting PDE5, Kamagra allows cGMP to persist longer in the penis, prolonging the vasodilation and enhancing the erectile response to sexual stimulation. Therefore, Kamagra indirectly affects nitric oxide levels by potentiating the natural process of nitric oxide-mediated vasodilation in response to sexual stimulation. It does not directly increase nitric oxide production but rather enhances the physiological response to nitric oxide release during sexual arousal.