GHRP-2 vs GHK
Side-by-side comparison of key properties, dosing, and research.
- Summary
- 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.
- 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.
- Half-Life
- 15–60 minutes
- Extremely short as free peptide; tissue binding extends local effects
- Admin Route
- SubQ, Intranasal
- SubQ, Topical, Oral
- Research
- —
- —
- Typical Dose
- 100–300 mcg
- 100–500 mcg
- Frequency
- 2–3 times daily
- Daily or 5x per week
- Key Benefits
- 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
- 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
- Side Effects
- Increased appetite
- Water retention
- Elevated cortisol (modest)
- Elevated prolactin (modest)
- +2 more
- Excellent safety profile (naturally occurring peptide)
- Rare: mild injection site reaction (SC)
- No significant adverse effects identified in research
- Stacks With
- —
- —