Isovaleryl-L-carnitine is a naturally occurring acylcarnitine that is formed via metabolic conversion of L-leucine. It increases survival and decreases apoptosis in hepatocyte growth factor-deprived murine C2.8 hepatocytes when used at a concentration of 1 mM. Isovaleryl-L-carnitine inhibits amino acid deprivation-induced proteolysis and autophagy in isolated perfused rat liver when used at concentrations of 77 and 100 μM, respectively. Increased levels of isovaleryl carnitine are associated with isovaleryl-CoA dehydrogenase deficiency (isovaleric acidemia).