GHK-Cu is the copper(II) complex of a naturally occurring tripeptide, glycyl-L-histidyl-L-lysine. It is one of the most widely studied copper-binding peptides in cell-biology research. This guide explains the molecule, what laboratory studies investigate, and how to read the paperwork for a batch.
- Class
- Copper(II) complex of the tripeptide Gly-His-Lys
- Structure
- Three amino acids; the GHK peptide itself is approx. 340 Da
- Appearance
- Blue to violet-blue lyophilised powder, because of the bound copper
- Supplied as
- Lyophilised vials; pre-filled pen formats
- Purity method
- RP-HPLC; identity by mass spectrometry; copper content where stated
What GHK-Cu is
The tripeptide GHK was first isolated from human plasma in the early 1970s. It binds copper(II) very tightly, and the resulting complex, GHK-Cu, is what most research refers to. Because the peptide is only three residues long it is simple to synthesise and characterise compared with larger peptides.
What the research literature studies
Published studies use cell cultures, such as skin fibroblasts, to examine how GHK-Cu relates to extracellular-matrix proteins and to gene-expression patterns. Others look at the chemistry of copper binding and how the complex behaves in solution. These are laboratory findings; nothing here is a claim about effects on people.
Identity and purity: what a good CoA shows
As well as RP-HPLC purity, a copper peptide has a visible identity check: the lyophilised powder should be blue to violet-blue. A white powder, or one that has turned brown or green, is a reason to ask questions before using it.
- RP-HPLC purity with the chromatogram attached
- Mass-spectrometry confirmation of the peptide
- Where available, a copper content figure confirming the complex rather than the free peptide
- A batch reference that matches your vial label
Handling and storage
Store sealed lyophilised material cold, dry and protected from light. Copper complexes can be sensitive to pH and to chelating agents in the solvent, which is one reason the choice of diluent matters. See our guides on diluents and on solubility and pH.
Regulatory status
GHK-Cu supplied by Nordapep is research-grade material. It is not a licensed medicine and is not a cosmetic ingredient, and it must not be used in or on people or animals. Finished cosmetic products that contain copper peptides are regulated separately and are not what this page describes.
Questions researchers ask
Why is GHK-Cu blue?
The colour comes from the copper(II) ion bound to the peptide. A blue to violet-blue powder is expected; a white powder suggests the peptide without its copper.
What is the difference between GHK and GHK-Cu?
GHK is the three-amino-acid peptide on its own. GHK-Cu is the same peptide with copper(II) bound to it, which changes its colour, chemistry and behaviour in solution.
What is the difference between the vial and the pen?
Both contain the same compound as a lyophilised or pre-filled research format. Each listing has its own batch reference and Certificate of Analysis.
Is GHK-Cu sold by Nordapep for cosmetic use?
No. It is supplied for in vitro laboratory research only and is not intended for use on people or animals.
