GHK-Cu is a marketing darling, which is a shame, because the underlying literature is more interesting than any banner ad and a good deal more careful. Read on its own terms, it is a tidy case study in how published reviews describe findings without overpromising. Here is a measured summary — emphasis on summary.
What GHK is, according to the literature
GHK is glycyl-L-histidyl-L-lysine, a small naturally occurring tripeptide. Reviews report that it is present in human plasma, saliva, and urine, and that its reported levels decline with age. It readily binds copper to form the complex usually written GHK-Cu, which is the form most discussed in the research.
What a widely cited 2015 review describes
A frequently referenced 2015 review by Pickart and colleagues describes roles discussed in the literature for GHK-Cu in skin repair and the remodeling of the extracellular matrix, in the attraction of immune and endothelial cells, and in broad influence on gene expression. The authors frame these as modulating roles across multiple cellular pathways — a description of research findings and hypotheses, not a product claim.
A second review, on copper and oxidative stress
A separate 2015 review in the journal Cosmetics discusses GHK-Cu in the context of copper regulation and the expression of numerous antioxidant genes, and raises the possibility that it influences oxidative-stress responses in skin. Crucially, the authors are explicit that causal links between the gene-expression changes they describe and the effects observed remain to be established. That caveat is the most important sentence in the paper.
GHK is reported in human plasma, saliva, and urine, with levels that decline with age.
GHK binds copper to form GHK-Cu, the form most discussed in the literature.
Much of the work concerns cellular pathways and gene expression in laboratory systems.
Reviews note that causal links between the observations remain to be established.
What this note is not
This is a summary of published literature about a molecule, not a statement about what any product does. Reviews describe research findings and propose hypotheses; they do not establish that a benchtop reference material produces any outcome in a person, and nothing here is guidance for use in people. Our GHK-Cu is a research reference material for in vitro laboratory use only — not for human or animal consumption.
Why we bother summarizing it carefully
Reading the literature accurately is part of being a serious supplier; overstating it is part of being a careless one. The most interesting molecules tend to be the ones whose own literature is honest about its open questions — and GHK-Cu, read carefully, is exactly that kind of molecule.