I honestly was very skeptical about how this product would work, since I have used tooth whitening toothpaste, strips, professional whitening before and nothing worked! A big issue was my teeth being EXTREMELY sensitive!! I was shocked when I applied the whitening gel, bracing for nerve pain, but actually feeling NOTHING. After using for about a week straight I noticed a HUGE difference in the color of my teeth.. It also worked on brightening some of the bonding I had on my front teeth, which typically don't whiten. With SNOW it all whitened! I would highly recommend this product!