Viagra, or sildenafil, primarily works by inhibiting phosphodiesterase-5 (PDE5). This enzyme normally breaks down cyclic guanosine monophosphate (cGMP), a crucial molecule for relaxing smooth muscle in blood vessel walls.
By blocking PDE5, Viagra allows cGMP levels to rise. Increased cGMP promotes relaxation of smooth muscles in the corpora cavernosa, the spongy tissues within the penis. This relaxation leads to vasodilation – widening of blood vessels.
The result? Increased blood flow into the penis, facilitating an erection. This mechanism is highly specific to the blood vessels involved in penile erection; it doesn’t significantly impact blood flow to other parts of the body.
It’s important to understand that Viagra doesn’t create sexual desire; it simply allows for a physical response to sexual stimulation. Sexual stimulation triggers the release of nitric oxide, which starts the cGMP pathway. Viagra enhances this natural process.
This targeted action on blood flow explains Viagra’s efficacy in treating erectile dysfunction. However, individual responses vary, and factors like age and overall health influence its effectiveness.
