Malegra 100 belongs to a group of medicaments known as PDE5 inhibitors. To learn exactly how the medicine works, it is essential to explain the physiological mechanism of erection. The enzyme PDE5 or phosphodiesterase type-5 inactivate cyclic GMP. By inhibiting this enzyme, Sildenafil citrate improves the amount of cyclic GMP and thus enhances erection . The main advantage of Sildenafil and other PDE5 inhibitors is that is works only in the presence of s**ual stimulation meaning that it resembles the natural mechanism of erection.Malegra 100 has an advantage over other medicine in that it lasts a lot longer – up to 4 hours