L-Palmitoylcarnitine is a long-chain acyl fatty acid derivative ester of carnitine which facilitates the transfer of long-chain fatty acids from cytoplasm into mitochondria during the oxidation of fatty acids. L-Palmitoylcarnitine, due to its amphipathic character is, like detergents, a surface-active molecule. By changing the membrane fluidity and surface charge they can change the activity of several enzymes and transporters localized in the membrane. L-Palmitoylcarnitine has been also reported to change the activity of certain proteins. On the contrary to carnitine, palmitoylcarnitine was shown to stimulate the activity of caspases 3, 7, and 8 and the level of this long-chain acylcarnitine increased during apoptosis. Palmitoylcarnitine was also reported to diminish the binding of phorbol esters, the protein kinase C activators, and the autophosphorylation of the enzyme. Apart from these isoform nonspecific phenomena, palmitoylcarnitine was also shown to be responsible for retardation in the cytoplasm of protein kinase C isoforms and and, in the case of the latter one, to decrease its interaction with GAP-43. Some of the physicochemical properties of palmitoylcarnitine may help to explain the need for coenzyme A-carnitine-coenzyme A acyl exchange during mitochondrial fatty acid import. The amphiphilic character of palmitoylcarnitine may also explain its proposed involvement in the pathogenesis of myocardial ischemia. L-Palmitoylcarnitine accumulates in ischemic myocardium and potentially contributes to myocardial damage through alterations in membrane molecular dynamics. This is a mechanism through which could play an important role in ischemic injury. Palmitoylcarnitine is characteristically elevated in carnitine palmitoyltransferase II deficiency, late-onset (OMIM: 255110). Moreover, L-palmitoylcarnitine is found to be associated with celiac disease, which is an inborn error of metabolism.