Our teeth whitening serum contains glycerin, sorbitol and silica hydrate. It can reduce yellow discoloration or stains by counteracting color degradation, returning teeth to a brighter smile, and is gentle on sensitive teeth and gums without stripping enamel or irritating gums. The way to use it is simple: press 1-2 pump gel onto the toothbrush, gently brush up and down from the inside to the outside for 1-2 minutes, and rinse thoroughly with water. It neutralizes the yellow in your teeth more naturally, thus hiding stains, increasing brightness, and refreshing your breath.