New — Free Peptide Starter Guide (2026): 13 chapters, 34 cited studies

Get it free
ToolsComparePE-22-28 vs Exenatide

PE-22-28 vs Exenatide

Side-by-side comparison of key properties, dosing, and research.

Cognitive Enhancement
PE-22-28
GLP-1 / Weight Loss AgonistsCognitive Enhancement
Exenatide
Summary
PE-22-28 is a synthetic analog of spadin derived from sortilin, designed to block TREK-1 potassium channels with rapid-onset antidepressant and neurogenic effects. It shows fast-acting depression relief (within 24 hours) and promotes hippocampal neurogenesis.
Exenatide is a GLP-1 receptor agonist derived from the Gila monster lizard peptide exendin-4, with 53% homology to human GLP-1 and natural resistance to DPP-4 degradation. Available as twice-daily (Byetta) or once-weekly (Bydureon) formulation, it is also being studied for Parkinson's disease neuroprotection.
Half-Life
Relatively short; CNS effects may persist due to neurogenic mechanisms
~2.4 hours (Byetta/twice-daily); Bydureon BCISE: weekly via microsphere release
Admin Route
SubQ, Intranasal
SubQ
Research
Typical Dose
200–400 mcg
5 mcg, titrate to 10 mcg
Frequency
Once daily
Twice daily
Key Benefits
  • Rapid-onset antidepressant effects (within 24 hours)
  • Promotes hippocampal neurogenesis
  • Improves cognitive performance and memory
  • Reduces anxiety and depressive behavior
  • Novel mechanism — does not act on serotonin/dopamine/GABA receptors directly
  • May help treatment-resistant depression
  • Neuroprotective effects
  • Blood glucose control in type 2 diabetes
  • Weight loss (average 2–3 kg in clinical trials)
  • Once-weekly extended-release formulation available
  • Reduces appetite and food intake
  • Possible neuroprotective in Parkinson's disease (Phase II trials)
  • Reduces systemic inflammation
  • May protect pancreatic beta cells
  • Cardiovascular neutral or potentially protective
Side Effects
  • Generally well tolerated in animal models
  • Limited human data available
  • Possible mild headache or transient mood changes at initiation
  • Injection site reactions (SC)
  • Nausea (most common, especially initially)
  • Vomiting
  • Diarrhea
  • Headache
  • +4 more
Stacks With