GHK
Research OnlyA naturally occurring tripeptide (Gly-His-Lys) with copper-binding affinity and wound healing properties. The base form of GHK without added copper. Endogenous to human plasma where it circulates bound to copper. Declines with age. Most research focuses on the copper-complexed form (GHK-Cu), making evidence for GHK alone limited. Primarily relevant as the precursor to GHK-Cu.
Glycyl-Histidyl-Lysine · GHK tripeptide · Liver cell growth factor
3 human studies
- Preclinical
- 56%
- Clinical
- 17%
Based on 18 cited sources
community-reported · not clinically demonstrated · very-low confidence
Demonstrated effect magnitude — not a recommendation or safety claim.
Research Depth 37: highest human tier is small uncontrolled open-label cosmetic data on the copper complex (1A=15), at high risk of bias (1B=5), low total human N (1C=4), only partially direct since nearly all functional evidence uses GHK-Cu rather than base GHK (1D=6), atop a substantial multi-study preclinical program (Maquart 3169264, Simeon 11121126, Arul 17049946; 1E=7). Mechanism 68: copper delivery to copper-dependent enzymes has measured high-affinity binding plus functional confirmation in fibroblast collagen induction (2A=30), proximal pathway largely mapped via gene-expression modulation (29986520; 2B=20), monotonic dose-response shown in fibroblast culture maximizing at 10^-9 M (2C=9), confirmed in in-vivo rat models (2D=9). Plausibility 72: mechanism->surrogate (collagen/GAG markers) established and surrogate->wound/skin benefit inferred (3A=27), coherent with wound and dermal biology (3B=22), supported by analogous copper peptides/matrikines (3C=14), core claim scoped to repair though the "4,000-gene/DNA-reset" framing is broad (3D=9). Global Coverage 66: replicated across independent groups and countries (France, USA, India, China, Korea; 4A=28, 4B=20), substantial diverse literature (4C=18), but no regulatory recognition as a drug (4D=0). Community Experience 48: niche but persistent enthusiast discussion (5A=12), multi-year cosmetic GHK-Cu track record (5B=15), broadly consistent themes (5C=11), no recurring adverse signal (5D=10). Overall 56 -> early-limited. Effectiveness community-reported (capped, very-low): no controlled human efficacy estimate for base GHK; the skin/repair effect signal rides on the copper complex and remains anecdotal for the bare tripeptide.
The proposed mechanisms of GHK are based primarily on studies of its copper complex (GHK-Cu). Human mechanistic data for GHK alone is very limited.
How It Works (Simplified)
GHK is a natural “signal molecule” released from damaged tissue. Its primary function is to bind copper and deliver it to repair processes:
Binds copper with extremely high affinity (Kd ~10^-16 M), delivering it to copper-dependent enzymes essential for tissue repair.
Up- and downregulates 4,000+ genes involved in DNA repair, antioxidant defense, and tissue remodeling pathways.
Stimulates fibroblasts to produce collagen, elastin, and glycosaminoglycans for extracellular matrix repair.
Inhibits iron release from ferritin in damaged tissues, reducing lipid peroxidation and oxidative damage.
Key Research: Pickart L, Margolina A (2018) comprehensive review of gene expression effects. PMID:29986520
Important Limitations
- GHK alone has minimal biological activity without copper
- Nearly all functional studies use GHK-Cu (the copper complex)
- The natural form in the body is GHK bound to copper
- Translation of GHK effects independent of copper is unconfirmed
- For practical applications, GHK-Cu is the relevant form
GHK rapidly binds copper with extremely high affinity (Kd ~10^-16 M). In vivo, GHK circulates bound to copper and is released from extracellular matrix during tissue injury.
PMID:29986520Topical GHK-Cu cosmetic use has been reported to improve skin density and reduce fine lines over weeks of application. Wound healing effects in animal models observed over days to weeks of treatment.
PMID:26236730Long-term effects of GHK (without copper) supplementation are not characterized. Endogenous GHK levels decline with age (200 ng/mL at age 20 to 80 ng/mL at age 60). Implications of supplementing GHK alone are unknown.
Research-based observations
This timeline reflects observations from published clinical and preclinical studies. Individual responses may vary significantly. This is not a guarantee of effects or a dosing schedule. Consult qualified healthcare providers for personalized guidance.
Good Signs (5 indicators)
Warning Signs (4 indicators)
Bad Signs (5 indicators)
For Research Evaluation Only
These quality indicators are general guidelines based on typical peptide characteristics. Professional laboratory testing (HPLC, mass spectrometry) provides definitive quality verification. This checklist is for initial visual evaluation only.
BPC-157
CompatibleDifferent regenerative mechanisms - GHK for copper delivery and collagen synthesis, BPC-157 for angiogenesis and tissue healing.
TB-500
CompatibleDifferent tissue repair targets - GHK affects gene expression and copper enzymes, TB-500 regulates actin for cell migration.
LL-37
CompatibleGHK's wound healing effects may complement LL-37's antimicrobial properties in wound care applications.
Epithalon
CompatibleDifferent anti-aging mechanisms - GHK for gene expression modulation and tissue repair, epithalon for telomerase activation.
GHK-Cu
AvoidGHK is the base peptide that complexes with copper to form GHK-Cu. Using both is redundant - GHK-Cu is the biologically active form.
Research Note: Interaction data is based on published literature, mechanistic understanding, and theoretical considerations. Most peptide combinations lack direct clinical study. This information is for educational purposes only and does not constitute medical advice. Always consult qualified healthcare providers.
Key Studies Cited
Full reference list available on request. All citations link to PubMed for verification.
This dossier synthesizes available evidence from peer-reviewed literature, regulatory documents, and clinical trial registries. Evidence strength ratings follow a modified GRADE approach.
For complete methodology details, see our Methodology page.
Important Disclaimer
This dossier is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making health decisions.
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