Go natural with Tom's Of Maine Toms Fennel Ff Tthpst (6x5.5 OZ). We use zinc citrate sourced from zinc - a naturally occurring mineral and xylitol, a natural ingredient derived from birch trees or corn. Plus, natural flavoring for a taste that will make you look forward to brushing. Natural, antiplaque, whitening, freshens breath and helps fight tartar.. (Note: Description is informational only. Please read the ingredient label on the product for more information and always consult your health professional with any questions prior to use.)