The deuterations of the common amino acids at 400 degrees C in aqueous base are reported. Protium-deuterium exchange is found to be rapid at the a carbon in all examples where decomposition was unimportant. Exchange was accompanied by racemization of the a chiral center, however. While rapid a deuteration was noted for all the amino acids, slower deuteration was also observed for some alkyl chains and aromatic groups as well. Amino acids having OH, SH, SS, or C=N groups on alkyl chains decomposed rapidly to multiple, uncertain products while OH substituted aromatic groups and proline survived the reaction conditions.