I recently purchased these strips at Costco because they didn't have the Crest strips. I'd never used whitening strips though I use whitening toothpaste all the time.

The strips are easy to put on and quickly mold to your teeth. However, I have to warn you that if your teeth are sensitive you may have problems with them. I loved these strips and they really did whiten my teeth significantly but they did cause heightened sensitivity.

My dentist said that the only difference between the $600 whitening jobs he does and over-the-counter strips is the strength. He says if you're really serious about whitening you could wear the strips for an hour without hurting your teeth.

All in all, if you're looking for an alternative to Crest, these strips are the way to go. I definitely recommend them for all you whitening types out there.