The best known metabolic effect of cortisol and other glucocorticoids on metabolism is the ability to stimulate gluconeogenesis (formation of carbohydrates from proteins and some other substances) by the liver. Cortisol also causes a moderate decrease in the rate of glucose utilization by most of the cells of the body. Both the increased rate of gluconeogenesis and the moderate reduction of glucose utilization by the cells causes blood glucose concentrations to rise.