Cenforce contains sildenafil citrate, which is a phosphodiesterase type 5 (PDE5) inhibitor. PDE5 is an enzyme that is responsible for the breakdown of cyclic guanosine monophosphate (cGMP), which is a chemical that plays a crucial role in the Cenforce Tablets process. By inhibiting PDE-5, sildenafil citrate allows cGMP to accumulate in the penis, leading to increased blood flow and a firmer erection.