Dr. Fan shampoo can't really wash white hair black. Dr. Fan shampoo is one of the common shampoo products in the market. According to official website, it can repair damaged hair, deeply nourish hair, remove dandruff and prevent hair from falling off. However, there is no conclusive scientific basis for whether Dr. Fan's shampoo can wash white hair black. The color of hair is determined by the pigment cells inside the hair. With the increase of age, the pigment cells gradually lose their activity and the hair will turn white. Therefore, hair whitening is a natural physiological phenomenon, which cannot be changed by external products such as shampoo. Some shampoo products advertised in the market can make white hair black. In fact, this effect is achieved by adding chemical components such as hair dye, but its use has certain risks and side effects, and it is not recommended to use it for a long time.