These whitestrips will make your teeth white when you follow the instructions. They're easy to use and figure out, but they tend to slide off of your teeth if you're not careful. The reason for the 3 star rating is due to the sensitivity that it causes. After using, my teeth starting getting very sensitive to anything cold, and I even got sharp pains in my teeth (which has never happened before). Though I would recommend these for white teeth, I'd also recommend to be careful when using.