Viagra, or sildenafil, works by selectively inhibiting phosphodiesterase type 5 (PDE5). PDE5 is an enzyme that breaks down cyclic guanosine monophosphate (cGMP), a crucial molecule for achieving and maintaining an erection. By blocking PDE5, Viagra allows cGMP levels to remain elevated.
Increased cGMP: The Key to Erection
Higher cGMP levels cause the smooth muscles in the blood vessels of the penis to relax. This relaxation leads to increased blood flow into the corpora cavernosa, the spongy tissues within the penis. The resulting engorgement of blood produces an erection.
This targeted inhibition of PDE5 is what makes Viagra effective for treating erectile dysfunction. It specifically targets the enzyme responsible for degrading the molecule needed for penile erection, leading to a more sustained and robust response.
