I have used whitening products many times, mouthwashes, toothpaste, and whitening strips. The whitening strips do make my gums sore and my teeth sensitive but not to excess. But after using this toothpaste for about two weeks my mouth would burn and broke out with a line of blisters just inside the lip area. I wasn't sure at first what caused it but realized that when I attempted to brush my teeth the toothpaste would burn that area. I quit using the toothpaste and the blisters/burn area is healing. I can only surmise that the toothpaste caused the burns or blisters. I did see the whitening effects but will not use the product again.