So I am not really impressed with these. They seem easy enough to use, peel, apply, wait and remove. And that is all you have to do, BUT in order to see the best results you need to do it everyday and for 30 minutes. It is difficult to talk with them in and you can not eat with them in (obviously). After about a week it became tiresome to remember to do and set aside the 30 minutes I wont be eating or talking.....hard for me to do :) Also, for the little bit I did use these I didn't notice much of a difference. They were whiter but they were also more sensitive.
Now on the flip side they are cheaper than going into a doctor.
So, if you have the discipline and time and only need a shade or two whiter, give them a try.