The phosphodiesterase type 5 enzyme is in charge of controlling the flow of blood in the penis.
When there is too much of this enzyme, it prevents the build-up of extra blood in the penis, preventing your erection from stiffening.
The Generic Viagra reduces the phosphodiesterase type 5 enzyme’s function and increases blood flow to the penis, resulting in a firm erection.
Without sexual stimulation, sildenafil and other phosphodiesterase type 5 inhibitors are inactive.
If you are not sexually aroused, they will not give you an unwanted erection.