Listerine advanced white is clinically proven to give you naturally whiter teeth from 2 weeks how listerine advanced white works cleans three powerful essential oils combine to kill germs left behind after brushing whitens amp protects from new stains non abrasive polyphosphate technology lifts stains to give naturally whiter teeth a protective shield blocks new stains from developing even in those hard to reach areas strengthens fluoride helps to toughen and strengthen teeth