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

Get it free
ToolsComparePalmitoyl Tetrapeptide-7 vs PE-22-28

Palmitoyl Tetrapeptide-7 vs PE-22-28

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

Skin & Cosmetic
Palmitoyl Tetrapeptide-7
Cognitive Enhancement
PE-22-28
Summary
Palmitoyl Tetrapeptide-7 (Rigin) is a cosmetic peptide consisting of palmitic acid linked to the tetrapeptide sequence GQPR (Gly-Gln-Pro-Arg). It was designed to mimic the biological activity of the IgG immunoglobulin C-terminus, which downregulates the production of interleukin-6 (IL-6), a key driver of skin aging and inflammation.
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.
Half-Life
Topical penetration-dependent; effects last hours to days
Relatively short; CNS effects may persist due to neurogenic mechanisms
Admin Route
Topical
SubQ, Intranasal
Research
Typical Dose
2-5 ppm concentration in formulation
200–400 mcg
Frequency
Twice daily
Once daily
Key Benefits
  • Reduces IL-6 inflammatory cytokine in skin
  • Prevents 'inflammaging' of the skin
  • Inhibits MMP collagen-degrading enzymes
  • Synergistic with Matrixyl for anti-aging
  • Clinically tested for wrinkle and skin texture improvement
  • Well-tolerated topically
  • 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
Side Effects
  • Contact sensitization (rare)
  • Well-tolerated at standard concentrations
  • Generally well tolerated in animal models
  • Limited human data available
  • Possible mild headache or transient mood changes at initiation
  • Injection site reactions (SC)
Stacks With