I love these. I've always been self-conscious of my yellow teeth, and I've wanted to try these for a while. Someone told me they made their teeth sensitive for a long time, so I wasn't sure about them. My teeth got a little sensitive about the 8th day, so I stopped for a few days and started again, using them once a day, (which is what the package suggests). They've been fine since then. I tried a sample of Listerine White Strips before these, and they were disgusting and didn't dissolve well at all. I like these way better. My teeth are so white. I love that I don't have to feel self-conscious about them anymore. My husband noticed the difference, too.