Feel better about your smile with our hassle-free 10-minute whitening formula and user-friendly LED device. No sensitivity, no irritation. Formulated at the Hismile Research Center. Clinically proven instant whitening results. Contains PAP, nHAp, and potassium citrate. As a bleaching agent, peroxide has an aggressive whitening mechanism known as oxidation through free radicals, which comes with some side effects. These side effects can include sensitivity, irritated gums, and the loss of essential minerals from the teeth. Chairside treatments performed by a dentist limit these reactions, but at-home treatments are riskier.