Did you know that peroxide is terrible for your gut flora (the healthy bacteria that lives inside your intestines and aids with digestion)? Peroxide can also weaken the enamel of your teeth over time with each use.  I will be honest and say that peroxide does whiten your teeth and it does it very quickly, but at what cost? Using a non peroxide based teeth whitening system is your best choice for getting a whiter and brighter smile without the harmful effects of peroxide.