zViagra works by mimicking nitric oxide which opens blood
vessels carrying blood to the
penis thereby increasing blood flow to the penis and facilitating an erection.
zViagra does not cause an erection by itself. Erotic
stimuli are still necessary to
cause the erection.
zViagra can have
effects on other parts of the cardiovascular system and men with heart conditions must be careful about
taking Viagra. Thus, some
men cannot take Viagra.
zViagra may or may not have an effect on a normal male
depending on their
zViagra does increase blood flow in women as well leading
to more vasocongestion and is
being studied with regards to its effect in women.