What should i know about bleaching teeth?

Results vary: Other things you should know are: teeth become more sensitive while bleaching, long use with weaker formulations whiten better and last longer than short term strong formulations, lights and lasers are gimmicks and don't whiten better, using custom fitted bleach trays from a dentists works better than otc strips, and lastly avoid staining food and drinks while bleaching; i.e. Coffee, wine.

Sensitivity: It may cause your teeth to become sensitive.