Review (4/5): They work!!
I agree with the other customers' reviews. This system does what it claims to whiter your teeth.
Listening to others' reviews, I try to be careful to put the strips into my mouth. So, I have no problem to put them in. However, it is definitely not allow you to talk freely when you have the strips in your mouth. I also don't think you can eat and drink while the strips in your mouth. I hope Crest will give some extra strips in case one mess up or break the strip unintentionally.
I also find that the strips are very small. I have small teeth but the strips are not able to cover them all. I think both the strips for upper teeth and lower teeth only design to cover the front 8 teeth both on the top and on the bottom. I am wondering what happens to my other back teeth.
Overall, I think you will get a brighter smile, but not a brighter laugh. It is because people will notice your back teeth are still look yellow.