Methods of inducing antinociception in a human are described. The method
includes the step of administering an effective dose of a polypeptide
comprising L-neo-tryptophan to the human extracranially. The polypeptide
containing L-neo-tryptophan could be, but is not limited to, NT64L,
NT65L, NT66L, NT67L, NT69L, NT69L', NT71, NT72, NT73, NT74, NT75, NT76,
or NT77.