Viagra, or sildenafil, primarily works by inhibiting an enzyme called phosphodiesterase-5 (PDE5).
PDE5 Inhibition and cGMP
PDE5’s role is breaking down cyclic guanosine monophosphate (cGMP), a crucial molecule for achieving and maintaining an erection. By blocking PDE5, Viagra increases cGMP levels.
- Higher cGMP levels relax the smooth muscles in the blood vessels of the penis. This relaxation increases blood flow into the penis. The increased blood flow leads to penile engorgement and erection.
Sexual Stimulation is Key
It’s crucial to understand that Viagra doesn’t automatically cause an erection. Sexual stimulation is necessary to trigger the release of nitric oxide, which initiates the cGMP pathway. Viagra simply enhances the effects of this naturally occurring process.
Other Effects
While primarily known for its effects on erectile function, Viagra can also affect blood vessels elsewhere in the body. This is why it’s sometimes used to treat pulmonary hypertension.
Improved blood flow to the lungs. Reduced blood pressure in the pulmonary arteries.
Individual Responses
The efficacy of Viagra can vary between individuals. Factors like age, overall health, and other medications can influence its effectiveness.
