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

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ToolsCompareHGH Fragment 176-191 vs Palmitoyl Tetrapeptide-7

HGH Fragment 176-191 vs Palmitoyl Tetrapeptide-7

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

Fat Loss & Metabolic
HGH Fragment 176-191
Skin & Cosmetic
Palmitoyl Tetrapeptide-7
Summary
HGH Fragment 176-191 (also known as AOD-9604) is a stabilized, modified fragment of the human growth hormone molecule corresponding to amino acids 176–191 with an addition of a tyrosine residue at the N-terminus. It retains HGH's fat-burning properties without the anabolic, diabetogenic, or IGF-1-stimulating effects.
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.
Half-Life
~30 minutes
Topical penetration-dependent; effects last hours to days
Admin Route
SubQ
Topical
Research
Typical Dose
250–500 mcg
2-5 ppm concentration in formulation
Frequency
1–3 times daily
Twice daily
Key Benefits
  • Selective fat burning without anabolic side effects
  • Reduces visceral and subcutaneous fat
  • No insulin resistance or blood glucose disruption
  • Does not stimulate IGF-1
  • May support cartilage and bone repair (at higher doses)
  • No effect on growth or organ size
  • 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
Side Effects
  • Injection site irritation
  • Temporary lethargy
  • Headache (rare)
  • Nausea (rare)
  • Contact sensitization (rare)
  • Well-tolerated at standard concentrations
Stacks With