I started using this last year because I really wanted to nice shiny teeth. My teeth are a little bit stained from smoking and drinking soda and coffee. I wasn't too sure if this would make my teeth sensitive because I am prone to that. I gave it a try and finished the box. They are pretty easy to apply and they stay on well. I didn't tell anyone I was using them because I wanted for my family to have an unbiased opinion and my mom randomly said " your teeth look so white and shiny today" I knew right then that they really do work very well. The only reason why I give it 4 out of 5 stars is because they slip around on my teeth a tiny bit and I hate HATE the taste of peroxide, but it is still worth it. I am getting married this October and I definitely plan to buy some more of these to get my teeth looking great for all the pictures that will be taken.