leucine enkephalin

Leucine enkephalin is an endogenous opioid pentapeptide neurotransmitter with the amino acid sequence Tyr-Gly-Gly-Phe-Leu. It is a **peptide biologic** that acts primarily as an agonist at the **delta opioid receptor**, with additional activity at the **mu opioid receptor** and little to no meaningful activity at the **kappa opioid receptor**. In drug development, leucine enkephalin has been formulated as an **intranasal spray** by Virpax Pharmaceuticals under code names including NES-100, NM-0127, NM-127, and PES-200, with the proposed brand name Envelta, for the treatment of pain and post-traumatic stress disorder; based on the provided context, that development program was in the preclinical stage as of November 2023.

Brand names

Envelta

Other names

leucine enkephalinleu-enkephalinTyr-Gly-Gly-Phe-Leu