What side effects do whitening strips have on your teeth?

Does the whitening wear away the enamel on your teeth?? Or have any other permanent negative effects besides sensitivity for a day or two?
--------------------
The whitener in the strips doesn't strip the enamel nor does it contain actual bleach. The whiteners are a more diluted variety of what is used in the dentist's office. The whiteners actually contain a type of "peroxide" which when used on the teeth, cause the "dentin" or "tubule" layer to be exposed or swell. This leads to sensitivity. If you are going to use a Whitening strip, get a toothpaste made for people with sensitive teeth. Slowly build up your tolerance to the whitening strips. Only apply them for half the time that the directions say. This means it will take longer to get your teeth brighter but you will be less sensitive.
Source