I got this product on sale at costco to try it out, and it does work pretty well! the strips stayed in well and didn't leave a yucky taste in my mouth when I was using them. they also didn't sting like some whitening products do. I definitely noticed my teeth were whiter, also. it's been a few months and I feel like they aren't as white as they were when used them, which sucks because I was hoping they'd last quite a while. I don't drink coffee or tea on the regular as well, which makes a difference.