Sildenafil Citrate, which is found in Kamagra 100 mg, is a PDE5 (phosphodiesterase type 5) inhibitor. Erectile dysfunction happens when the arteries and blood vessels in the penis get narrowed. This makes it hard for blood to flow to the penis. Sildenafil Citrate blocks the PDE5 enzyme that causes this constriction while increasing the release of nitric oxide (NO).
