Valproic Acid Ethyl Ester-d5 is the isotope labelled analog of Valproic Acid Ethyl Ester (V094770); the ethyl ester derivative of one of the major antiepileptic drugs, Valproic Acid (V094750). Valproic Acid Ethyl Ester has potential to be used as a biofuel, has a pleasant odor, and displays marked resistance to clouding and crystallization.