A molecule is not a molecule is not a molecule – at least in terms of the potency and possible side effects of drugs that those molecules make up. This paper examines the effects of racemic mixtures in drugs, stressing the reasons why it is important to produce drugs that are comprised of a single enantiomer. After providing an overview of the basic chemical concepts involved, this paper will describe the importance of single-enantiomer drugs as supported by regulations from the Federal Drug Administration.