. “Malegra Professional” typically refers to a formulation of Sildenafil (the same active drug as in Viagra). Here’s how it works in the body (its mechanism): Mechanism of Action of Malegra Professional ***** Stimulation → NO Release When a man is *****ly aroused, nitric oxide (NO) is released in the *****, especially in the corpus cavernosum (the erectile tissue). Wikipedia +2 cyno.co.in +2 NO Activates Guanylate Cyclase NO stimulates an enzyme called guanylate cyclase, which increases the level of cyclic guanosine monophosphate (cGMP) in smooth muscle cells. nyredcross.org +1 cGMP Causes Muscle Relaxation Elevated cGMP leads to relaxation of smooth muscles in the blood vessels of the corpus cavernosum. This relaxation causes the blood vessels to dilate (vasodilation), allowing more blood to flow in. Wikipedia +1 Sildenafil Inhibits PDE5 Sildenafil (the active ingredient in Malegra) specifically inhibits phosphodiesterase type 5 (PDE5). PDE5 is the enzyme that normally breaks down cGMP. Wikipedia +1 More cGMP, Better Erection By blocking PDE5, sildenafil prevents the breakdown of cGMP. So, cGMP stays around longer and at higher concentrations, which enhances and prolongs smooth muscle relaxation → this leads to improved blood flow into the ***** → firmer erection. cyno.co.in +1 Requirement of ***** Stimulation Importantly, sildenafil does not cause an erection on its own; ***** stimulation is needed to trigger NO release and start the cascade. NAFDAC Greenbook +1 Selectivity Sildenafil is relatively selective for PDE5: it inhibits PDE5 much more than many other phosphodiesterases, which reduces side effects. NAFDAC Greenbook