Met-Enkephalin

Methionine enkephalin (Met-enkephalin; opioid growth factor, OGF) is an endogenous pentapeptide (Tyr-Gly-Gly-Phe-Met) that acts at classical mu- and delta-opioid receptors for pain modulation and, in its OGF role, functions as a tonic inhibitor of cell proliferation through interactions with the nuclear OGF receptor (OGFr, the zeta-opioid receptor), a pathway with distinct biological implications from classical analgesic opioid signaling. The OGF-OGFr axis operates as an endogenous homeostatic brake on cell cycle progression: OGF binds OGFr in the nucleus to upregulate cyclin-dependent kinase inhibitors p16 and p21, inhibiting S-phase entry; this mechanism has been characterized in models of wound repair, organ development, and immune cell regulation.

immune modulation, cell proliferation regulation, anti-inflammatory, autoimmune support.

Research on Met-Enkephalin primarily documents effects related to immune modulation and cell proliferation regulation and anti-inflammatory and autoimmune support. These are areas covered in preclinical and clinical literature — individual response varies and effects depend on context of use.

For Met-Enkephalin, its FDA status is not evaluated by the FDA, and it is designated for research use only. Regulatory status reflects publicly available information and may change. This is not legal or medical advice.

2 providers in the directory currently offer Met-Enkephalin.

# Summary This study demonstrated that adults with trichotillomania (hair-pulling disorder) have significantly lower peripheral levels of met-enkephalin and β-endorphin compared to healthy controls, with the focused hair-pulling subtype showing the lowest opioid peptide levels. Researchers observed that these reduced endogenous opioid levels may be associated with reward and stress-related mechanisms underlying the disorder, suggesting distinct neurobiological differences between hair-pulling subtypes.