Abstract
GHK-Cu is the smallest peptide in routine research supply: three residues — glycine, histidine, lysine — clamped around a single copper(II) ion. The free tripeptide GHK (C₁₄H₂₄N₆O₄, ≈340.4 Da) is a fragment of human collagen and circulates endogenously; the supplied reagent is its copper complex, CAS 89030-95-5, formula C₁₄H₂₃CuN₆O₄⁺, mass near 402.9 Da.
This dossier maps the primary record: where the molecule was first pulled out of plasma, why the literature treats the copper as structural rather than incidental, and the two bodies of work — connective-tissue chemistry and transcriptomics — that GHK-Cu is cited for. It is a reference, not a protocol. It states no human or animal effect and gives no dosing. Material supplied by Valtrax Research, including the GHK-Cu listing, is a research input for in-vitro work inside Canada — nothing more.
Key findings
- GHK is endogenous: it circulates near 200 ng/mL in young plasma and falls by more than half by the seventh decade — the decline is what first drew researchers to it. [5]
- The copper is structural, not optional. Activity across the literature tracks the GHK-Cu complex, never the bare tripeptide. [1]
- The firmest data sit in connective tissue — collagen and glycosaminoglycan synthesis in fibroblast culture [2] and connective-tissue accumulation in rodent wounds. [3]
- A second, broader line reads GHK as a transcriptional modulator, weighted toward repair and antioxidant programs. [4]
Spec Sheet
Glycyl-L-histidyl-L-lysine copper(II)
- Name
- Glycyl-L-histidyl-L-lysine copper(II)
- Also known as
- GHK-Cu · Copper tripeptide-1 · Cu-GHK · GHK:Cu²⁺
- Molecular formula
- C₁₄H₂₃CuN₆O₄⁺
- Molecular weight
- 402.93 g/mol (complex)
- CAS number
- 89030-95-5
- PubChem CID
- 71587328
- Sequence (1-letter)
- GHK
- Sequence (3-letter)
- Gly-His-Lys
Where the molecule comes from
GHK entered the literature as a behavior before it was a structure. In 1973, Loren Pickart isolated a factor from human plasma that made aged liver tissue behave like young tissue in culture, and narrowed the activity to a single glycyl-histidyl-lysine tripeptide that bound copper avidly. [1] The copper affinity surfaced from the same line of work — the metal was not an additive, it travelled with the peptide.
The peptide is endogenous and abundant in youth. Reviews put plasma GHK near 200 ng/mL in young adults, declining to roughly a third of that by age sixty. [5] That age-linked fall is the observation that has framed most of the work since: a molecule the body makes less of as tissue loses its capacity to remodel.
Why the copper carries the activity
Treat the metal as part of the molecule. GHK binds Cu(II) with high affinity, and the copper sits in a square-planar coordination site built from the N-terminal amine, the imidazole nitrogen of histidine, and a deprotonated backbone amide nitrogen. [5] The lysine side chain stays free; the geometry is what defines the species.
This matters for interpreting any test readout. Across the published record it is the complex — GHK-Cu — that registers activity, not the naked tripeptide. Copper handling is the thread the connective-tissue and gene-expression accounts both hang on, so identity and net-content figures on a certificate describe a coordination complex, not a simple peptide salt.
The connective-tissue record
The load-bearing column of the GHK-Cu literature is matrix chemistry. Maquart and colleagues (1988) reported that the tripeptide-copper complex stimulated collagen synthesis in fibroblast cultures; [2] a 1993 follow-up carried the finding in vivo, with GHK-Cu raising connective-tissue accumulation in rat experimental wounds. [3] Together they put GHK-Cu on the map as a copper-driven modulator of collagen and glycosaminoglycan output.
The published work clusters in a few preparation types:
- Fibroblast cultures measuring collagen and glycosaminoglycan synthesis
- Rodent wound and connective-tissue accumulation models
- Copper-transport preparations probing metalloproteinase balance
- Dermal and skin-regeneration systems used in the later reviews
GHK as a transcriptional lever
A second body of work reads GHK less as a matrix reagent and more as a signal. Transcriptomic analyses report the peptide shifting the expression of a large fraction of measured genes, weighted toward tissue-repair and antioxidant-defense programs. [4] Pickart's later reviews fold the wound, gene-expression, and antioxidant readouts into one account, while keeping the copper-driven matrix story as the best-replicated core. [5]
For a bench reader the distinction is practical: the connective-tissue endpoints are concrete and reproduced across groups, while the broad transcriptional claims are framed by review syntheses and warrant the original sources before being leaned on.
Reading the verification
Open the certificate before you order. Valtrax GHK-Cu is verified by an independent third-party lab and the result is published to the verification record, so you check it on the lab's portal — not on our word. A few lines carry the weight:
- Identity — the measured result should resolve to the GHK-Cu complex, not just free tripeptide.
- Purity — reported as area percent by HPLC.
- Net peptide content — how much of the vial is the coordination complex versus water and counter-ion.
- Lab reference — the Janoshik report number that ties the verified sample to the certificate in your order.
Handling the lyophilized vial
GHK-Cu ships as a lyophilized powder — a deep-blue solid, the color a tell of the bound copper. The handling notes below track standard laboratory practice for peptides of this class:
- Sealed, dry: hold at −20 °C for long-term storage, protected from light.
- Reconstitution: bring up in the solvent set by the lab's own procedure before use.
- After reconstitution: keep cold and consume inside the window the protocol defines; copper complexes are sensitive to pH and oxidation in solution.
Status in Canada
Health Canada has authorized no human or animal use of GHK-Cu, and no marketing authorization exists for any clinical or cosmetic application of the research-grade material. Labs hold it as a research input for in-vitro procedures, nothing else. Valtrax Research offers no guidance on administering it to humans or animals and endorses none. Sales are domestic and carry a written research-use confirmation at checkout.
Frequently asked
Is the copper part of the molecule or just an additive?
Part of the molecule. GHK binds copper(II) in a square-planar site, and across the literature it is the GHK-Cu complex — not the bare tripeptide — that registers activity. The copper is structural.
What are the identity numbers for GHK-Cu?
The copper complex: CAS 89030-95-5, formula C₁₄H₂₃CuN₆O₄⁺, mass ≈402.9 g/mol, PubChem CID 71587328, sequence GHK (Gly-His-Lys). The free tripeptide GHK is C₁₄H₂₄N₆O₄, ≈340.4 Da.
Is GHK something the body already makes?
Yes. GHK is a fragment of human collagen and circulates in plasma — near 200 ng/mL in young adults, declining with age. That endogenous decline is what first drew researchers to it.
Whose lab put it on the map?
Loren Pickart isolated the tripeptide from human plasma in 1973 and characterized its copper binding. Maquart and colleagues anchored the connective-tissue work in fibroblast cultures and rat wounds from 1988 onward.
Can you administer GHK-Cu to people in Canada?
No. Health Canada has not approved GHK-Cu for human, animal, or cosmetic use. It is supplied only as a research input for in-vitro laboratory work.
References
- [1]Pickart, L. & Thaler, M.M. (1973). Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol 243(124):85–87. PMID 4349838
- [2]Maquart, F.X. et al. (1988). Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu²⁺. FEBS Lett 238(2):343–346. PMID 3169264
- [3]Maquart, F.X. et al. (1993). In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu²⁺ in rat experimental wounds. J Clin Invest 92(5):2368–2376. PMID 8227353
- [4]Pickart, L. et al. (2015). GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration. Biomed Res Int 2015:648108. PMID 26236730
- [5]Pickart, L. & Margolina, A. (2018). Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci 19(7):1987. PMID 30021970