GPE vs PACAP-38

Head-to-head comparison of GPE (Glycyl-L-prolyl-L-glutamic acid) and PACAP-38 (Pituitary Adenylate Cyclase-Activating Polypeptide-38 (human PACAP-38)) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyGPEPACAP-38
CategoryCognitive EnhancementCognitive Enhancement
Full NameGlycyl-L-prolyl-L-glutamic acidPituitary Adenylate Cyclase-Activating Polypeptide-38 (human PACAP-38)
Molecular Weight301.30 Da4534 Da
Half-Lifeminutesminutes
Amino Acids338 aa
Typical Dose0.1-10 mg/kg preclinical10-100 µg preclinical range
RouteIntranasal/IntracerebroventricularIntranasal
Purity≥98%≥98%
Studies Count25650
Research StatusPre-clinicalPre-clinical

GPE Benefits

  • memory consolidation
  • neuroprotection
  • synaptic plasticity
  • learning support

PACAP-38 Benefits

  • synaptic plasticity
  • BDNF upregulation
  • neuroprotection
  • memory consolidation

GPE Dosing

intranasal or ICV research doses|0.1-10 mg/kg preclinical range|repeat daily or intermittent protocols

PACAP-38 Dosing

0.1-1 nmol ICV in rodents|10-100 µg intranasal in preclinical studies|single-dose or short repeated protocols

GPE Side Effects

  • limited human safety data
  • short half-life
  • local irritation with nasal delivery

PACAP-38 Side Effects

  • headache-like effects
  • flushing
  • hypotension

Research Overview

GPE

Preclinical studies suggest GPE can reduce neuronal damage and support plasticity-related pathways in the brain. Research interest centers on hippocampal function, which links it to learning and memory paradigms.

PACAP-38

PACAP-38 is one of the most studied endogenous neuropeptides for protecting neurons from ischemic and excitotoxic damage. Preclinical literature also links it to hippocampal plasticity and learning-related signaling, including increased BDNF expression.

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Common Stacking Partners

GPE stacks with:

davunetidenoopeptarginine-vasopressin

PACAP-38 stacks with:

citicolinealpha-gpcomega-3
tripeptideneuroprotectionmemoryneurotrophicbdnfsynaptic-plasticity