Obesity is a worldwide epidemic that can lead to the development of a number of disorders including type 2 diabetes, hypertension, and atherosclerosis. It develops when energy intake exceeds energy expenditure. Many receptors involved in the regulation of energy balance are G protein-coupled receptors (GPCRs). GPCRs are the largest and most diverse group of mammalian membrane receptors. Research has shown that GPCRs regulate virtually all metabolic processes, such as glucose and energy homeostasis, and are involved in the development and progression of ?-cell dysfunction, insulin resistance, obesity, and type 2 diabetes. As such, the GPCR superfamily has emerged as potential targets for the treatment of metabolic disorders. R&D Systems offers a wide variety of tools for investigating the role of GPCRs in obesity and related metabolic disorders.