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

Get it free
ToolsCompareHGH Fragment 176-191 vs PGPIPN

HGH Fragment 176-191 vs PGPIPN

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

Fat Loss & Metabolic
HGH Fragment 176-191
Immune Support
PGPIPN
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.
PGPIPN is a bioactive hexapeptide (Pro-Gly-Pro-Ile-Pro-Asn) derived from beta-casein during enzymatic digestion. It exhibits anti-inflammatory properties via opioid receptor modulation and cytokine suppression, making it relevant for gut health, systemic inflammation, and as a component of casein-derived functional foods.
Half-Life
~30 minutes
Estimated 30-120 minutes (peptide degradation)
Admin Route
SubQ
Oral, Subcutaneous (research)
Research
Typical Dose
250–500 mcg
200-500 mg per day
Frequency
1–3 times daily
Once or 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
  • Anti-inflammatory effects via cytokine suppression
  • Gut mucosal protection and intestinal barrier support
  • Opioid receptor modulation for gut motility regulation
  • Potential analgesic activity via central and peripheral opioid pathways
  • Explored for inflammatory bowel conditions and gut dysbiosis
  • Natural origin (food-derived) with favorable safety profile
Side Effects
  • Injection site irritation
  • Temporary lethargy
  • Headache (rare)
  • Nausea (rare)
  • Generally very well-tolerated given food-derived origin
  • Theoretical opioid-mediated constipation at high doses
  • Rare milk protein allergy in casein-sensitive individuals
Stacks With