Endomorphin-2
Opioid / AnalgesiaAlso known as: EM-2, Tyr-Pro-Phe-Phe-NH2
Endogenous Opioid PeptidesResearch phase: PreclinicalRegulatory: Not approved. Research peptide only.
Mechanism
Endomorphin-2 is one of the most selective natural painkillers for the mu-opioid receptor. It produces strong analgesia with potentially fewer side effects than morphine.
Technical detail
Endomorphin-2 (Tyr-Pro-Phe-Phe-NH2) is a tetrapeptide exhibiting the highest known selectivity and affinity for the mu-opioid receptor among endogenous peptides (Ki ~0.36 nM). It produces potent antinociception with reduced respiratory depression and constipation compared to classical opioids in preclinical models.