Cholecystokinin-8 vs Endomorphin-1

Head-to-head comparison of Cholecystokinin-8 (Cholecystokinin (sulfated C-terminal octapeptide, CCK-8)) and Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2) — benefits, dosing, side effects, research data, and where to buy.

PropertyCholecystokinin-8Endomorphin-1
CategoryEndocrine PeptidesPain Management
Full NameCholecystokinin (sulfated C-terminal octapeptide, CCK-8)Tyr-Pro-Trp-Phe-NH2
Molecular Weight1143.2 Da610.71 Da
Half-Life1-2 minMinutes in plasma
Amino AcidsDY(SO3H)MGWMDF-NH24
Typical Dosephysiologic low-picomolar-nanomolar range|research-dependent0.1-10 ug per animal
Routeendogenous secretion|research IV/SCIntrathecal / subcutaneous
Purity≥98%≥98%
Studies Count97600
Research StatusEndogenousPre-clinical

Cholecystokinin-8 Benefits

  • gallbladder contraction
  • pancreatic enzyme release
  • satiety signaling

Endomorphin-1 Benefits

  • mu-opioid selectivity
  • potent antinociception
  • endogenous peptide scaffold
  • useful for receptor-discovery studies

Cholecystokinin-8 Dosing

physiologic secretion|research-dependent

Endomorphin-1 Dosing

Intrathecal 0.1-10 ug per animal|Subcutaneous 0.1-5 ug per animal|In vitro 0.1-100 nM

Cholecystokinin-8 Side Effects

  • abdominal cramping
  • nausea
  • biliary contraction

Endomorphin-1 Side Effects

  • respiratory depression at high exposure
  • sedation
  • tolerance and dependence potential

Research Overview

Cholecystokinin-8

CCK-8 is a canonical gut hormone fragment with extensive documentation in digestive physiology and appetite control. Sulfation of the tyrosine residue is important for high-affinity receptor activity.

Endomorphin-1

Endomorphin-1 is a key research peptide in studies of endogenous mu-opioid signaling and spinal analgesia. Like other peptide analgesics, its main translational hurdles are enzymatic instability, limited oral bioavailability, and delivery across barriers.

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Common Stacking Partners

Cholecystokinin-8 stacks with:

gallbladderpancreassatiety

Endomorphin-1 stacks with:

gabapentinketamine
gut-hormonesatiety-peptideendocrine-peptidemu-opioidendogenous-peptideanalgesiapain-modulation