Misc: Deeply whitens for up to four shades (When brushing twice daily for six weeks). 2% hydrogen peroxide. Gluten free. Enamel safe. Improved formula (Twice the level of hydrogen peroxide vs. previous Colgate Optic White Advanced). Goes beyond surface stains with our patented 2% hydrogen peroxide formula. Deeply whitens for up to four shades (When brushing twice daily for six weeks). Some people may experience tooth sensitivity or gum discomfort when using whitening products. This discomfort is temporary and not harmful. If you experience more than mild tooth sensitivity, stop use and consult your dentist. www.colgateopticwhite.com. Save Water: Turn off the tap while brushing. SmartLabel.