The easiest and most effective way to turn gray hair into black hair is to use hair dye as a treatment. However, it should be noted that hair dye application can only achieve the goal of treating the symptoms, and the hair that has just grown out will still be white. White hair is mainly due to the hair follicles at the root of the hair stop producing melanin production, in general the appearance of white hair is mostly due to genetic factors. The condition may also be caused by kidney deficiency, blood deficiency, stress, frequent late nights, and poor diet. The patient’s age may also lead to the appearance of gray hair, you can go to the Chinese medicine department of the hospital for consultation, take Chinese medicine soup for treatment to relieve symptoms. You can eat more black beans, black sesame, walnuts and wolfberries to turn white hair black, but it takes a process and it is not certain how long it will take.