are allergic to sildenafil, as contained in VIAGRA and Revatio®, or any in the substances in VIAGRAare allergic to sildenafil, as contained in VIAGRA and Revatio®, or any in the components in VIAGRAGet in to the mood. You won't get an erection just by using VIAGRA. You have to be sexually stimulated for it to work.Más o menos a la media hora de