Adiponectin is a secreted adipokine belonging to the C1q/collagen superfamily and is encoded by the ADIPOQ gene. With a monomer molecular weight of 26–30 kDa, it serves as a core functional protein regulating systemic glycolipid metabolic homeostasis. Predominantly synthesized and abundantly secreted into the bloodstream by white adipose tissue, adiponectin exists as trimers, hexamers, and highly active high-molecular-weight multimers, among which high-molecular-weight oligomers are the primary functional form. By binding to AdipoR1/AdipoR2 receptors, adiponectin activates the AMPK signaling pathway, promoting fatty acid oxidation, inhibiting hepatic gluconeogenesis, and improving insulin sensitivity. It also exerts potent anti-inflammatory, anti-atherosclerotic, and tissue-protective effects. Contrary to most adipokines, circulating adiponectin levels are significantly downregulated in obesity, insulin resistance, type 2 diabetes, and metabolic syndrome, making it a critical diagnostic biomarker and research target for metabolic disorders.