Copper Peptides Explained: GHK-Cu, AHK-Cu and Cosmetic Peptides
GHK-Cu is a naturally occurring copper-binding tripeptide. This guide explains what copper peptides are and how they relate to other cosmetic peptides.
Key takeaways
- GHK is the tripeptide Gly-His-Lys, first isolated from human plasma in 1973.
- GHK forms a complex with copper(II); the complex is called GHK-Cu.
- Cosmetic peptides such as palmitoyl pentapeptide-4 and acetyl octapeptide-3 are a related but separate group.
What is a copper peptide?
A copper peptide is a short peptide that binds a copper(II) ion. The best known is GHK-Cu. GHK is the tripeptide glycyl-L-histidyl-L-lysine, which has a strong affinity for copper. It was isolated from human plasma by Loren Pickart and colleagues in 1973 and has since been reported in other body fluids.
Research interest
GHK-Cu has been studied in laboratory settings, particularly in cell and animal models of tissue remodelling, and it is widely used as an ingredient in cosmetic science. As with any peptide, results in a model system should not be read as evidence about effects in people.
AHK-Cu
AHK-Cu is a related tripeptide, alanyl-histidyl-lysine, that also binds copper. It is used in comparison studies and appears in the same conversations as GHK-Cu.
Other cosmetic peptides
- Palmitoyl pentapeptide-4 (Matrixyl): a five-amino-acid peptide (Lys-Thr-Thr-Lys-Ser) with a palmitoyl fatty acid attached to help it associate with lipid membranes.
- Acetyl octapeptide-3 (SNAP-8): an eight-amino-acid peptide that is N-acetylated.
These modifications, acylation and acetylation, are typical of cosmetic peptides and are explained in the peptide glossary.
Quality considerations
Copper complexes add another quality question: the ratio of copper to peptide. Ask what testing has been done, and store the material as described in our storage guide.