Listerine antibacterial mouthwash stay white has a special formula which can help to ensure that your teeth are left whiter than ever before this antibacterial mouthwash works by fighting bacteria and thoroughly cleansing stained and discoloured teeth caused by a build up or tartar to leave you with a beautifully white smile that you can be proud ofit contains zinc chloride formula which attacks the build up or plaque and tartar which in turn can prevent your teeth from becoming discoloure