Pantethine, dimeric form of pantothenic acid, is a biologically active form of the B5 vitamin and an intermediate in the production of Coenzyme A. It is available as a dietary supplement, and is used support the healthy blood-cholesterol profile. Pantethine has shown an ability to favorably impact a variety of risk factors in people with hypercholesterolemia, arteriosclerosis and diabetes. It is thought that pantethine, in conjunction with the intermediary cysteamine, inhibits acetyl-coenzyme (CoA) carboxylase and 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, thereby affecting TG synthesis and lipoprotein metabolism. Pantethine increases CoA levels within the cells, which favorably modifies lipoprotein metabolism. The full mechanism of action of pantethine in lowering cholesterol levels is not fully understood. Since homocysteine is believed to contribute to the onset and progression of atherosclerosis and is involved in the biosynthesis of CoA, it is possible that pantethine impacts homocysteine.