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