GHK vs GHRP-2
Side-by-side comparison of key properties, dosing, and research.
- Summary
- GHK is the natural tripeptide (Gly-His-Lys) released from human albumin that activates tissue remodeling, collagen synthesis, and anti-aging gene expression. The copper-free form is the biological signaling molecule; it chelates copper in tissue to form GHK-Cu but also has independent biological activity.
- GHRP-2 is a potent synthetic hexapeptide that stimulates growth hormone release by activating ghrelin receptors in the pituitary and hypothalamus. It produces one of the strongest GH pulses among GHRPs, though unlike Ipamorelin it does cause modest increases in cortisol and prolactin.
- Half-Life
- Extremely short as free peptide; tissue binding extends local effects
- 15–60 minutes
- Admin Route
- SubQ, Topical, Oral
- SubQ, Intranasal
- Research
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- Typical Dose
- 100–500 mcg
- 100–300 mcg
- Frequency
- Daily or 5x per week
- 2–3 times daily
- Key Benefits
- Stimulates collagen and extracellular matrix synthesis
- Activates tissue repair gene expression programs
- Anti-aging: reverses 57% of age-related gene changes
- Antioxidant and anti-inflammatory
- Wound healing and skin barrier repair
- Improves skin laxity, texture, and radiance
- Neuroprotective (stimulates NGF, BDNF)
- Anti-fibrotic in liver and lung models
- Strong GH pulse stimulation
- Increased IGF-1 levels
- Enhanced muscle growth and recovery
- Improved fat metabolism
- Better sleep quality
- Increased bone density
- Enhanced appetite (less pronounced than GHRP-6)
- Anti-aging effects via GH axis optimization
- Side Effects
- Excellent safety profile (naturally occurring peptide)
- Rare: mild injection site reaction (SC)
- No significant adverse effects identified in research
- Increased appetite
- Water retention
- Elevated cortisol (modest)
- Elevated prolactin (modest)
- +2 more
- Stacks With
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