Electron paramagnetic resonance has been used to investigate the effects of interaction of acetylcarnitine with cytoskeletal proteins in human erythrocyte membranes. This compound, currently in clinical trials as a potential therapeutic agent for Alzheimer's disease, caused a highly significant increase in cytoskeletal protein-protein interactions. Carnitine, the parent compound, also increased cytoskeletal protein-protein interactions, suggesting that the acetyl group is not hydrophobic enough to direct acetylcarnitine to the bilayer phase of the membrane. Consistent with this suggestion, no change in lipid order or dynamics with acetylcarnitine was observed. These results are discussed in terms of possible implications to Alzheimer's disease treatment.