HGH Fragment 176-191 vs Pentapeptide-18
Side-by-side comparison of key properties, dosing, and research.
Fat Loss & Metabolic
HGH Fragment 176-191Skin & CosmeticAnti-Aging & Longevity
Pentapeptide-18- 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.
- Pentapeptide-18 (Leuphasyl) is a synthetic pentapeptide that mimics the sequence of enkephalin, an endogenous neuropeptide. It acts on neuronal pain receptors in facial muscles to reduce muscle contraction intensity and depth of expression lines, functioning similarly to Argireline (Acetyl Hexapeptide-3) but via a different receptor mechanism.
- Half-Life
- ~30 minutes
- Not applicable (topical)
- Admin Route
- SubQ
- Topical
- Research
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- Typical Dose
- 250–500 mcg
- 0.005–0.05% 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 depth of expression lines (forehead, crow's feet, glabellar)
- Inhibits acetylcholine release for muscle-relaxing effect
- Complementary mechanism to Argireline for enhanced anti-wrinkle activity
- Reversible and well-tolerated
- No risk of systemic paralysis at cosmetic concentrations
- Suitable for daily use in serums and creams
- Side Effects
- Injection site irritation
- Temporary lethargy
- Headache (rare)
- Nausea (rare)
- Generally very well-tolerated topically
- Rare skin sensitivity or mild irritation
- Theoretical opioid receptor desensitization with very prolonged high-dose use (not documented cosmetically)
- Stacks With
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