Insulin is a hormone produced by the beta cells of the pancreas and plays a crucial role in the regulation of glucose metabolism in the human body. Its primary function is to maintain glucose homeostasis, which means keeping blood glucose levels within a normal range.When blood glucose levels rise, such as after a meal, insulin is released into the bloodstream. Insulin facilitates the uptake of glucose by cells, particularly in the liver, skeletal muscles, and adipose tissue fat cells . It does so by binding to insulin receptors on the surface of these cells, which triggers a series of intracellular events that lead to the translocation of glucose transporters GLUT4 to the cell membrane. This allows glucose to enter the cells and be used for energy production or stored as glycogen in the liver and muscles or as triglycerides in adipose tissue .In addition to promoting glucose uptake, insulin also inhibits the breakdown of glycogen glycogenolysis and the production of glucose from non-carbohydrate sources gluconeogenesis in the liver. This further helps to reduce blood glucose levels.Moreover, insulin has anabolic effects on protein and lipid metabolism. It stimulates protein synthesis, inhibits protein degradation, and promotes the synthesis and storage of lipids while inhibiting lipolysis the breakdown of fats .In summary, insulin plays a vital role in the regulation of glucose metabolism in the human body by promoting glucose uptake by cells, inhibiting glucose production and release from the liver, and modulating protein and lipid metabolism. These actions collectively help to maintain blood glucose levels within a normal range and ensure that cells have a constant supply of energy.