Palmitoyl-D-carnitine is a long-chain acylcarnitine, an isomer of palmitoyl-L-carnitine , and the D enantiomer of palmitoyl-DL-carnitine .1 It inhibits carnitine palmitoyltransferase with a Ki value of 2.1 mM for 14C-palmitoylcarnitine synthesis by erythrocyte membranes.