The increasing prevalence of metabolic diseases poses a significant threat to public health,high-lighting the urgent need to identify effective therapeutic targets.Humanin(HN),a 24-amino acid linear peptide synthe-sized from mitochondrial DNA,has been previously acknowledged for its neuroprotective properties.Recent research indi-cates that HN can regulate glucose and lipid metabolism and has shown promise in treating metabolic disorders in animal models using either HN or its analogs.This review outlines the fundamental biological functions and signal transduction mechanisms of HN,and comprehensively evaluates its role and therapeutic potential in type 2 diabetes mellitus,nonalco-holic fatty liver disease,atherosclerosis and polycystic ovary syndrome,aiming to examine the potential of HN as a target for the prevention and treatment of metabolic diseases.