Used this toothpaste when I was 10 years old. 23 now. Had to go to the doctor because of tissue build up on the back on my head. Only thing I've used different was this toothpaste. Stopped using it and the tissue build up went right away. Found it a bit strange. Never ever used since. This toothpaste does contain more sodium Fluoride than crest toothpaste, which was the first tooth paste to come out with fluoride in it. Guessing I took a allergic reaction to Sodium fluoride so watch out people.