비아그라에 대한 사실 아무도 제안하지 않는다

Sexual stimulation that causes an erection leads to the output and release of nitric oxide from the penis. Nitric oxide causes an enzyme, guanylate cyclase, to create cyclic guanosine monophosphate (cGMP) that's generally accountable for escalating and reducing the size of blood vessels carrying blood to and from your penis and resulting in an erec