This is not true. Toothpaste has no whitening effect. The main component of toothpaste is friction agent, which can clean food residue and soft dirt on teeth. In addition, the effect is not great, so whitening toothpaste can't really whiten, so you only need to choose your favorite taste when choosing toothpaste. Cheap or expensive toothpaste is almost always effective. If you want to whiten, you need a special stomatology department to do cold light whitening, and the effect will be better. The cold light whitening effect can last for about 2 years, as long as it is not a food with heavy pigment, the effect is still ok. Toothpaste is a kind of paste-like product applied to the surface of human teeth by friction, and its main purpose is cleaning. Generally gel-like, it is usually applied to a toothbrush to clean the tooth surface and teeth and its surroundings through the mechanical friction of the toothbrush, so that the oral cavity can be purified and fresh.