PainResearch Phase

Endomorphin-2

Endogenous peptide

Overview

Endomorphin-2 is a tetrapeptide (Tyr-Pro-Phe-Phe) that, like endomorphin-1, demonstrates highly selective agonism at mu-opioid receptors. The two endomorphins differ by a single amino acid but share similar receptor selectivity and analgesic properties.

Mechanism of Action

Endomorphin-2 is found in spinal and supraspinal sites involved in nociception. Its unique selectivity profile has generated interest in developing analogs that retain efficacy while minimizing respiratory depression and other opioid side effects..

Research Summary & Key Findings

Animal studies have confirmed potent analgesic activity of endomorphin-2 in thermal and inflammatory pain models following central administration. As with endomorphin-1, clinical utility is limited by rapid peptidase degradation and poor systemic bioavailability. Medicinal chemistry efforts have produced modified analogs with improved stability, though none have advanced to late-stage clinical trials.

Clinical Status

Research Phase

Endomorphin-2 is in the research phase with limited clinical data in humans. Current evidence is primarily derived from preclinical (animal or in vitro) studies.

Administration Routes

Endogenous peptide

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Disclaimer: This information is provided for educational and research purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide therapy. The Peptide Association does not endorse or recommend any specific treatment protocol.