Fluoride. While fluoride is supposedly the ingredient that prevents cavities, it doesn’t do that job very well and can actually be very toxic to the body. In fact, if you suffer from acne outbreaks around the mouth and chin area, fluoride toothpaste may be the cause! (If you haven’t already, check out The Case Against Fluoride and The Fluoride Deception for more information.) Fluoride-free toothpastes are becoming more common, but unfortunately it’s not the only ingredient in toothpaste you should be avoiding. Read more about fluoride dangers here.