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Met-Enkephalin
Overview
Met-enkephalin is a pentapeptide (Tyr-Gly-Gly-Phe-Met) that differs from leu-enkephalin only in its C-terminal amino acid. It acts as an endogenous opioid with preferential delta-opioid receptor activity and also binds mu-opioid receptors.
Mechanism of Action
Derived from proenkephalin, met-enkephalin is involved in pain modulation, stress responses, and immune regulation. Like other enkephalins, it is subject to rapid enzymatic degradation by aminopeptidases and enkephalinases.
Research Summary & Key Findings
Met-enkephalin has been characterized in numerous preclinical studies demonstrating analgesic and neuromodulatory effects when central degradation is prevented. Clinical translation has been hindered by the peptide's instability and inability to cross the blood-brain barrier. Synthetic analogs with enhanced stability, such as DADLE, have been investigated but have not achieved widespread clinical use.
Clinical Status
Met-Enkephalin 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
References
Primary literature
- PubMed: "Met-Enkephalin"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Met-Enkephalin"
Registered interventional and observational studies, including status and phase.
- PubChem: "Met-Enkephalin"
Chemical structure, molecular properties, and bioactivity data.
Study-level citations for this compound are being verified against the primary sources before publication. The database queries above return the current indexed literature in the meantime.
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View detailsNo lawful pathway today
Met-Enkephalin is not FDA-approved and does not currently have a lawful prescription or compounding pathway in the United States, so there is nothing for us to sell you here and no consultation to book. That can change: eight peptides moved back to a lawful pathway in February 2026.
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List Your PracticeDisclaimer: 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. See our editorial policy for how this content is produced and reviewed.