Met-enkephalin vs DPDPE

Head-to-head comparison of Met-enkephalin (Tyr-Gly-Gly-Phe-Met) and DPDPE ([D-Pen2, D-Pen5]-enkephalin) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyMet-enkephalinDPDPE
CategoryPain ManagementPain Management
Full NameTyr-Gly-Gly-Phe-Met[D-Pen2, D-Pen5]-enkephalin
Molecular Weight573.67 Da645.79 Da
Half-Life1-5 minutes in plasma15-60 minutes in plasma
Amino Acids55
Typical Dose0.1-5 ug per animal0.01-1 ug per animal
RouteIntrathecal / intracerebroventricularIntrathecal / intracerebroventricular
Purity≥98%≥98%
Studies Count1200800
Research StatusPre-clinicalPre-clinical

Met-enkephalin Benefits

  • endogenous opioid signaling
  • analgesic reference ligand
  • spinal antinociception
  • neurochemical pain-pathway probe

DPDPE Benefits

  • delta-opioid selectivity
  • improved conformational stability
  • analgesic receptor mapping
  • useful in chronic pain models

Met-enkephalin Dosing

Intrathecal 0.1-5 ug per animal|Intracerebroventricular 0.1-2 ug per animal|In vitro 1-100 nM

DPDPE Dosing

Intrathecal 0.01-1 ug per animal|Intracerebroventricular 0.01-0.5 ug per animal|In vitro 0.1-20 nM

Met-enkephalin Side Effects

  • sedation at higher exposure
  • constipation-like opioid effects
  • rapid enzymatic degradation

DPDPE Side Effects

  • sedation
  • nausea-like opioid effects
  • tolerance with repeated dosing

Research Overview

Met-enkephalin

Met-enkephalin has been extensively used in receptor pharmacology and nociception studies to map mu and delta opioid biology. The main limitation in translational work is very short half-life from peptidase cleavage and poor systemic stability.

DPDPE

DPDPE is widely cited in opioid pharmacology because it helped establish the functional role of delta-opioid receptors in pain control. Its constrained structure is also used to explore how peptide cyclization changes potency, stability, and tissue selectivity.

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Common Stacking Partners

Met-enkephalin stacks with:

gabapentinketamine

DPDPE stacks with:

morphinegabapentin
opioid-peptideenkephalinmu-opioidanalgesiacyclic-peptidedelta-opioidenkephalin-analog