Sildenafil acts by blocking phosphodiesterase 5 (PDE5), an enzyme that promotes breakdown of cGMP, which regulates blood flow in the penis. It requires sexual arousal, however, to work. It also results in dilation of the blood vessels in the lungs.
How does sildenafil work in the body?
Sildenafil works by preventing the action of a chemical in your body, called phosphodiesterase type-5. This helps to widen (relax) blood vessels and improves the flow of blood to the penis following sexual stimulation. This helps to maintain an erection.
Does Sildenafil keep you hard after coming?
Strictly speaking, no, Viagra does not keep you hard after ejaculation. Nevertheless, studies suggest that it could reduce your refractory period, and it will work for 4-6 hours, meaning that once your refractory period's over, you should have no trouble getting another erection.
