C-peptide vs PACAP-38

Head-to-head comparison of C-peptide (Connecting peptide (C-peptide)) and PACAP-38 (Pituitary Adenylate Cyclase-Activating Polypeptide-38 (human PACAP-38)) — benefits, dosing, side effects, research data, and where to buy.

Research Score

PropertyC-peptidePACAP-38
CategoryPain ManagementCognitive Enhancement
Full NameConnecting peptide (C-peptide)Pituitary Adenylate Cyclase-Activating Polypeptide-38 (human PACAP-38)
Molecular Weight3020.3 Da4534 Da
Half-Life~20-30 minminutes
Amino Acids3138 aa
Typical Doseno approved analgesic dose|research-only10-100 µg preclinical range
RouteIV|subQIntranasal
Purity≥98%≥98%
Studies Count46650
Research StatusPre-clinicalPre-clinical

C-peptide Benefits

  • diabetic neuropathy research
  • nerve function support
  • possible analgesic effect

PACAP-38 Benefits

  • synaptic plasticity
  • BDNF upregulation
  • neuroprotection
  • memory consolidation

C-peptide Dosing

0.5-1.0 mg/day in research|route varies by protocol

PACAP-38 Dosing

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

C-peptide Side Effects

  • injection-site reactions
  • unknown long-term safety

PACAP-38 Side Effects

  • headache-like effects
  • flushing
  • hypotension

Research Overview

C-peptide

C-peptide is not an approved analgesic, but multiple studies have examined its effects on peripheral nerve blood flow and neuropathy outcomes. The strongest relevance is in diabetic neuropathic pain rather than migraine.

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

C-peptide stacks with:

C-peptideConnecting peptide

PACAP-38 stacks with:

citicolinealpha-gpcomega-3
neuropathic-paindiabetic-neuropathynerve-repairneurotrophicbdnfsynaptic-plasticityneuroprotection