The hair color comes from melanin. Hair pigmentation can be divided into 3 relatively indepen-dent stages: proliferation and differentiation of melanocytes, synthesis of melanin in melanocytes, and mela-nin transportation. The regulation mechanisms of these 3 stages are different. At present, the substances that promote the generation of hair melanin mainly include hormones, nutrients, antioxidants, and other drugs with various action mechanisms. This paper reviews the research progress of the mechanism of melanin syn-thesis and drugs for treating premature gray hair, analyzes some unclear and important problems involved in hair color formation, and the prospects of related drugs, in order to provide better understanding of mecha-nism of hair color formation and find more effective measures for preventing premature gray hair.