Nearly a decade of research has resulted in the identification and classification of brain peptides whose effects in humans resemble those of opiates, such as morphine. The word 'endorphin' is a contraction of endogenous morphine. Endorphins are constituent body chemicals found naturally in all human beings and in many other animals. Endophins appear to duplicate the effects (physical and pharmacological) in humans of narcotics, such as morphine, heroin, and other opium derivatives. Essentially, endorphins are internal narcotics which, if supplied from an external source, would be criminally prescribed. Regulation of pain perception is one likely role for endorphins: another is the regulation of narcotic tolerance and dependence as well as the control of various emotions. Each person is addicted to his/her endorphins, and any significant depletion of them can result in withdrawal symptoms similar to those associated with termination of addictive narcotic use. Severe stress appears to be a cause of endorphin depletion. It is conceivable that endorphins conceivable that endorphins can be synthetically produced and sold as are vitamin supplements. It would not make sense, however, to outlaw the use of morphine and heroin when they are so similar to endorphins. Clearly the finding that the body naturally possesses a substance which is outlawed if introduced externally requires a rethinking of the basis for narcotics laws. Thirty-two references are listed.