Charcoal toothpaste is used to whiten teeth, improve bad breath, and remove surface stains. \nHow it works \nWhitening: Charcoal is abrasive, which helps wear down stains. \nBad breath: Charcoal can help freshen breath. \nRemoving stains: Charcoal adsorbs extrinsic stains, which are stains that affect the overall appearance of teeth.