You can use black beans or small black beans for black hair. According to the relevant public information, both big black beans and small black beans have hair care and other effects, which can promote the synthesis and secretion of melanin in hair. Black soybean is a traditional Chinese medicine ingredient, which is rich in various nutrients, such as protein, minerals, vitamins, etc. It has the functions of nourishing liver and kidney, enriching blood and benefiting qi, and nourishing black hair. Among them, melanin and anthocyanin in black beans can promote the synthesis and secretion of melanin in hair, thus improving the problems of white hair, alopecia and dry hair, which has a certain effect on hair care and blackening. Small black beans contain protein, minerals, vitamins and other nutrients, and are also rich in active ingredients such as melanin and anthocyanin, which can promote the synthesis and secretion of melanin in hair, thus having a certain effect on blackening hair.