Sildalis, which contains Sildenafil Citrate, acts on a specific enzyme known as phosphodiesterase type five (PDE5). This generic medicine simply inhibits the enzyme PDE5, which further increases the levels of cyclic Guanosine Monophosphate and Nitric Oxide. When these chemicals are enhanced, the blood circulation is greatly augmented, including the male reproductive system. The penile organ receives a sufficient amount of blood in order to attain a rigid erection for a longer period.