Natural & artificial flavor. Proven to reduce stains & whiten teeth. Whiten + whoa! Whiten - Clinically proven to whiten teeth, reducing stains by an average of 50% (chewing 2 pieces after eating, along with regular brushing, for 4 weeks). Whoa! - Refreshing mango kiwi power stripe and cooling xylitol. 33% fewer calories than sugared gum. Calorie content per serving has been reduced from 15 to 10 calories.