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

Get it free
ToolsComparePE-22-28 vs Tirzepatide

PE-22-28 vs Tirzepatide

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

Cognitive Enhancement
PE-22-28
GLP-1 / Weight Loss Agonists
Tirzepatide
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.
Tirzepatide is an FDA-approved dual GIP/GLP-1 receptor agonist that produces greater weight loss than semaglutide in head-to-head trials. SURMOUNT-1 trial showed average 21% body weight reduction at 72 weeks at the highest dose. Marketed as Mounjaro (diabetes) and Zepbound (obesity).
Half-Life
Relatively short; CNS effects may persist due to neurogenic mechanisms
~5 days
Admin Route
SubQ, Intranasal
SubQ
Research
Typical Dose
200–400 mcg
2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg
Frequency
Once daily
Once weekly, subcutaneous
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
  • Average 21% body weight reduction at highest dose (SURMOUNT-1)
  • Superior to semaglutide in head-to-head SURPASS trials
  • Dual GIP/GLP-1 mechanism for enhanced metabolic control
  • Significant reduction in HbA1c for type 2 diabetes
  • Improved cardiovascular risk markers
  • Reduces visceral fat preferentially
  • FDA-approved for T2DM (Mounjaro) and obesity (Zepbound)
  • Weekly dosing
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 during titration)
  • Vomiting
  • Diarrhea or constipation
  • Abdominal pain
  • +3 more
Stacks With