GHK-Cu (Copper Peptide)
GHK-Cu Peptide: Structure and Copper Chelation
Reviewed by our laboratory team · Last updated 2026-07-03
GHK-Cu is a Gly-His-Lys tripeptide that chelates a copper(II) ion through the imidazole nitrogen of histidine, the α-amino group of glycine, and the deprotonated amide nitrogen between glycine and histidine. This 3N donor set gives GHK-Cu high affinity and selectivity for Cu²⁺.
Key facts
- Coordination
- 3N donor set (imidazole, α-amine, amide)
- Cu²⁺ affinity
- Log K ~16 at physiological pH
- Colour
- Deep blue solution (Cu-peptide complex)
How does GHK bind copper?
The histidine imidazole is the primary anchor. Glycine's amino group and the deprotonated backbone amide complete the square-planar coordination. Lysine's side chain remains free, giving the complex a net charge that affects membrane interactions.
Extended research context
The GHK-Cu (Copper Peptide) deep dive
Deep dive: why the copper ion matters
The GHK tripeptide (Gly-His-Lys) coordinates a Cu²⁺ ion through the imidazole nitrogen of histidine, the terminal α-amino group of glycine, and a deprotonated peptide-bond nitrogen. This near-square-planar geometry is what gives the complex its characteristic deep-blue colour and its redox-modulating chemistry. Uncomplexed GHK is a different molecule pharmacologically — nearly every peer-reviewed study attributes activity to the copper-bound form, which is why suppliers ship the pre-complexed GHK-Cu rather than plain GHK.
GHK-Cu in the transcriptomic literature
The most-cited modern papers on GHK-Cu come from the Pickart & Margolina group and independent transcriptomic re-analyses. GHK-Cu has been reported to modulate expression of >4,000 human genes at nanomolar concentrations in Broad Institute Connectivity Map re-analyses — including genes involved in DNA repair, antioxidant defence, and ECM remodelling. This gene-signature-level activity is the reason GHK-Cu appears in so many research reviews outside of dermatology.
Analytical fingerprinting of GHK-Cu
On reverse-phase HPLC, GHK-Cu elutes as a well-defined peak; free GHK and copper-free peptide impurities are distinguishable. UV-Vis at ~520 nm confirms the copper d-d transition band. Reputable suppliers publish both HPLC (≥98% area) and mass-spec identity (~340 Da complex, 340.4 free peptide) on the batch CoA.
Research applications
- ▸In vitro fibroblast and keratinocyte gene-expression studies
- ▸ECM turnover assays (collagen, elastin, decorin, MMP profiling)
- ▸Wound-healing scratch assays in cell culture models
- ▸Antioxidant-mechanism studies (copper redox modulation)
- ▸Formulation R&D: cosmetic and topical carrier compatibility research
Handling checklist
- ✓Store lyophilised vial at 2–8 °C, protected from light
- ✓Reconstitute with bacteriostatic or sterile water; expect a blue-tinted solution
- ✓Avoid contact with reducing agents (ascorbic acid destabilises Cu²⁺)
- ✓Aliquot reconstituted solution for freeze/thaw minimisation
- ✓Verify blue colour and CoA HPLC ≥98% before use
Common research-handling mistakes
Learnt from thousands of researcher orders across our UK labs.
✗ Buying GHK without copper
Fix: Confirm the CoA reads GHK-Cu (copper-bound); free GHK is a different pharmacology.
✗ Mixing with vitamin C in solution
Fix: Ascorbate reduces Cu²⁺ to Cu⁺ and destabilises the complex — keep them separate.
✗ Exposing to sunlight
Fix: Store in amber vial or foil-wrapped container at 2–8 °C.
Continue researching
Peer-reviewed guides, comparators and matched reference materials.
Related questions researchers ask
- Is GHK-Cu the same as copper peptide?
- What does GHK-Cu do in research studies?
- Is GHK-Cu safe for topical formulation research?
- What concentration of GHK-Cu is used in cell culture?
- How is GHK-Cu different from GHK alone?
Frequently asked questions
- Why is GHK-Cu blue?
- The Cu²⁺–peptide charge-transfer band absorbs in the red region, giving the characteristic deep blue colour.
Primary sources & clinical trials
Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab (external, rel="nofollow").
- RefPickart & Margolina, Int J Mol Sci 2018mdpi.com
- PubMedPickart & Margolina, GHK Peptide as a Natural Modulator of Multiple Cellular Pathways — Oxid Med Cell Longev 2018 (PMID 30110435)pubmed.ncbi.nlm.nih.gov
- PubMedPickart et al., GHK-Cu may prevent oxidative stress — Biomolecules 2015 (PMID 26436412)pubmed.ncbi.nlm.nih.gov
- PubMedPickart, The human tri-peptide GHK and tissue remodelling — J Biomater Sci Polym Ed (PMID 18538807)pubmed.ncbi.nlm.nih.gov
- PubChemPubChem · Glycyl-L-histidyl-L-lysine (CID 73587)pubchem.ncbi.nlm.nih.gov
- PubChemPubChem · GHK-Cu copper complex (CID 71145)pubchem.ncbi.nlm.nih.gov
- PubMedNIH PubMed — GHK-Cu wound healing literaturepubmed.ncbi.nlm.nih.gov
- GuidelineGoogle — Creating helpful, reliable, people-first contentdevelopers.google.com
More GHK-Cu (Copper Peptide) articles
- What Is GHK-Cu? Copper Peptide Research OverviewGHK-Cu is a naturally occurring copper-binding tripeptide (glycyl-histidyl-lysine-Cu²⁺) discovered in 1973. Structure, mechanism, and research history.
- What Does GHK Stand For?GHK stands for Glycine-Histidine-Lysine — the three amino acids of the tripeptide sequence. The Cu suffix indicates the copper(II) complex.
- GHK vs GHK-Cu: The DifferenceGHK is the free tripeptide; GHK-Cu is the copper(II) complex. Research literature focuses on GHK-Cu, which has distinct biological activity.
- GHK-Cu Mechanism: How the Copper Peptide WorksGHK-Cu mechanism: acts as a matrikine signalling molecule, modulates gene expression, and delivers copper for enzymes involved in extracellular matrix biology.
- The 1973 Discovery of GHK-CuGHK-Cu was discovered in 1973 by Loren Pickart while investigating differences between young and aged human plasma effects on liver-cell cultures.
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- Bacteriostatic WaterWhat Is Bacteriostatic Water?Bacteriostatic water is sterile water containing 0.9% benzyl alcohol as a bacteriostatic preservative. The benzyl alcohol inhibits bacterial growth after the vial's initial puncture, making the same vial suitable for repeated withdrawal in research handling. It is not the same as plain sterile water.