Viagra, or sildenafil, works by inhibiting a specific enzyme called phosphodiesterase-5 (PDE5). This enzyme breaks down cyclic guanosine monophosphate (cGMP), a crucial molecule for achieving and maintaining an erection. By blocking PDE5, Viagra allows cGMP levels to rise.
Increased cGMP and Erection
Elevated cGMP levels trigger the relaxation of smooth muscles in the penis. This relaxation increases blood flow into the corpora cavernosa, the spongy tissues within the penis responsible for erection. The increased blood flow, combined with reduced venous outflow, creates the engorgement necessary for a firm erection.
Specific Effects and Considerations
It’s important to note that Viagra only facilitates an erection; sexual stimulation is still required. Viagra’s effects typically last for several hours. Consult your doctor before use, particularly if you have heart problems, high blood pressure, or are taking other medications, as interactions are possible.
