GHK-Cu: what the copper-peptide research actually says

What GHK-Cu is

GHK is a tripeptide — glycyl-L-histidyl-L-lysine — identified by Loren Pickart in 1973 as a component of human plasma. Its defining property is that it binds copper(II) with high affinity, forming the complex written GHK-Cu.

The copper is not incidental. The histidine imidazole and the peptide backbone together form a coordination site, and most of the published biology is attributed to the complex rather than to the bare peptide. Researchers generally describe GHK as a copper carrier, delivering the ion to copper-dependent enzymes rather than acting alone.

What the literature reports

The earliest work described GHK as a factor that improved the survival of cultured hepatocytes. Later studies moved to connective tissue: Maquart and colleagues reported stimulation of collagen synthesis in fibroblast culture, and subsequent work examined decorin and the matrix metalloproteinases.

The most cited modern paper is Pickart and Margolina's 2018 review in the International Journal of Molecular Sciences, which reads the older pharmacology against gene-expression data. Separately, Campbell and colleagues reported in Genome Medicine that GHK reversed a gene-expression signature associated with emphysematous lung destruction — a result in tissue and cell models, not a clinical outcome.

Where the evidence stops

Almost all of this is in vitro or in animal models. GHK-Cu is widely used as a cosmetic ingredient, and that is a different regulatory category from a demonstrated clinical effect; a compound can be safe enough for topical cosmetic use without having proven a therapeutic one.

There are no large randomised human trials establishing a clinical indication. Anyone reading the literature should treat the gene-expression and cell-culture findings as mechanistic leads, which is how the authors themselves frame them.

Handling notes

GHK-Cu is supplied lyophilised and is the one compound in the catalogue with a visible tell: the copper complex gives the powder and its solution a blue tint. That colour is expected and is not a sign of contamination.

Copper complexes are light- and oxidation-sensitive, so the practical handling questions are the ordinary ones — cold storage, protection from light, and documenting the lot. This article gives no reconstitution volumes, concentrations or quantities; that is a matter for the researcher's own protocol.

References

1. Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol. 1973;243(124):85–87.
2. Pickart L. The human tri-peptide GHK and tissue remodeling. J Biomater Sci Polym Ed. 2008;19(8):969–988.
3. Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987.
4. Maquart FX, Pickart L, Laurent M, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu²⁺. FEBS Lett. 1988;238(2):343–346.
5. Campbell JD, McDonough JE, Zeskind JE, et al. A gene expression signature of emphysema-related lung destruction and its reversal by the tripeptide GHK. Genome Med. 2012;4(8):67.