The metabolic syndrome is a group of abnormalities including obesity, high blood pressure, hyperinsulinemia, high blood glucose levels and hyperlipidemia that together greatly increase the risk of developing cardiovascular disease and Type 2 diabetes. Hydrogen sulfide (H(2)S) is a vasodilatory gasotransmitter mediator in the cardiovascular system, proposed as an endothelium-derived relaxing factor. A lack of H(2)S and its synthesizing enzyme, cystathionine γ-lyase, in the vasculature causes hypertension, whereas an increase in the pancreas reduces insulin secretion. Thus, research is making inroads to determine whether H(2)S is involved in the pathogenesis of the metabolic syndrome. Several laboratories are synthesizing and testing clinically used drugs that release H(2)S. Some of these compounds are being tested for effectiveness in the metabolic syndrome.