What GHK-Cu is
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine. The peptide itself occurs naturally in human plasma, where its concentration is reported to decline substantially with age — an observation that has driven much of the research interest in it.
What distinguishes it from every other compound in this catalogue is that it is a coordination complex, not a peptide alone. The copper ion is held by the histidine imidazole nitrogen and the peptide backbone in a specific geometry, and the complex — not the free tripeptide — is the species the research literature concerns.
Molecular profile
| Property | Value |
|---|---|
| Also known as | Copper tripeptide-1 |
| Sequence | Gly-His-Lys |
| CAS number (complex) | 89030-95-5 |
| Molecular formula | C14H22CuN6O4 |
| Molecular weight | ~403.9 Da |
| Appearance | Deep blue to blue-violet powder |
The colour is a specification
GHK-Cu is blue. Not off-white, not faintly tinted — visibly, unmistakably blue, from the d-d electronic transitions of the coordinated copper(II) ion.
This makes it the one compound on this site where a visual check carries real information. Uncomplexed GHK tripeptide is a white powder and costs significantly less to produce. Material sold as GHK-Cu that arrives white is either not complexed, or not GHK at all.
The corollary is that colour is a necessary condition, not a sufficient one. Blue tells you copper is present; it does not tell you the peptide is correct, that the stoichiometry is right, or that the complex is pure. That still requires the analysis.
Research context
Published work on GHK and its copper complex includes:
- Extracellular matrix remodelling — reported effects on collagen and glycosaminoglycan synthesis in cultured dermal fibroblasts, and on the balance between matrix metalloproteinases and their tissue inhibitors.
- Gene expression — broad transcriptional profiling studies have reported changes across large numbers of genes in cultured human fibroblasts.
- Copper delivery — the complex is studied as a physiological copper transport form, which places it in trace metal biology as well as in dermal research.
- Angiogenesis and wound models — largely in-vitro and preclinical.
Supplied for in-vitro laboratory research only. No therapeutic claim is made and no dosing or administration guidance is provided.
Analytical notes
Characterising a metal complex raises questions that a plain peptide does not.
Purity of what, exactly. An HPLC purity figure for GHK-Cu describes the chromatographic profile of the material, but copper complexes can behave awkwardly on reversed-phase columns — the complex can partially dissociate on the column depending on mobile phase conditions, producing peaks for both the complexed and free peptide. A method that has not been developed for the complex can produce a purity figure that means something other than it appears to.
Copper content is a separate question. The peptide can be 99% pure and the copper stoichiometry still be wrong. Complete characterisation of a metal complex involves establishing the metal content, not only the organic component. If a certificate reports only HPLC purity, it has not addressed the copper.
Mass spectrometry sees the isotope pattern. Copper has two stable isotopes (⁶³Cu and ⁶⁵Cu) in roughly a 69:31 ratio, which produces a distinctive isotopic signature in the mass spectrum. Its presence is good confirmatory evidence that the copper is actually coordinated to the molecule being measured.
Handling and storage
Store sealed at −20 °C, protected from light and moisture. GHK-Cu is hygroscopic; a vial left open will take up atmospheric water. Bring to room temperature before opening.
In solution, copper complexes are pH-sensitive and can dissociate outside their stable range. Store reconstituted solution at 2–8 °C, protected from light, and prepare fresh where the work depends on the complex being intact.
What we supply
Released against a ≥99% purity specification, with HPLC and mass spectrometry on every batch and a batch-specific Certificate of Analysis that records appearance alongside the analytical results. Select batches additionally receive independent third-party purity verification.