I’ve gone to have my teeth whitened professionally at the dentist, and I’ve used bleach I’ve purchased from the dentist in the past. This kit is at least as good, if not better. It quickly erased surface stains I had from not bleaching in a long time, and my teeth are back whiter than ever. The cost of the whitening pens is also much less than the syringes of bleach from my dentist. Absolutely recommend!