Disappointing.
So sorry but this product did not work for me.  If there is any change it is difficult for me to see.  I did use teeth whitening strips years ago that worked very well.  I can't remember the brand but they were not Crest strips.  My12th time applying these my teeth actually started hurting.  That sounds a bit odd, doesn't it?  But I removed them and tossed the rest.
Rating: 1 stars