GHK-Cu: 50 mg ($30)

Overview

GHK-Cu is a three-amino-acid peptide bound to a copper ion. The peptide portion occurs naturally in human plasma, and its defining characteristic is an unusually strong affinity for copper. GHK-Cu is most studied for its potential benefits for skin, with some potential for hair as well. For hair specifically, there is a closely related copper peptide whose research centers on those benefits — see AHK-Cu: 50 mg.

In plain terms

Copper is essential to a number of enzymes, but free copper ions in tissue are chemically reactive and can cause damage. The body handles this by keeping copper bound to carrier molecules that hold it securely and hand it off only where it is needed. GHK is one such carrier — a very short peptide, just glycine, histidine, and lysine, that grips a copper ion tightly between them.

It was found by accident. In 1973 Loren Pickart was comparing blood plasma from young donors against plasma from older ones, and noticed that aged liver tissue exposed to the young plasma began synthesizing proteins at rates more typical of young tissue. The molecule responsible turned out to be this three-amino-acid fragment. Plasma levels of it fall substantially with age, and that observation is what most of the subsequent research has been built around. The bulk of that work concerns skin and connective tissue, and much of it involves topical or cell-culture applications rather than systemic exposure.

What has drawn the most attention since is the breadth of its activity at the gene level. Analysis using the Broad Institute's Connectivity Map — a database recording how gene activity in cultured cell lines shifts when exposed to thousands of different compounds — found that GHK raised or lowered the expression of roughly a third of all human genes by more than half, a figure usually cited as around 4,000 genes. The pattern is not random: one frequently referenced breakdown counts 47 DNA repair genes increased against only 5 decreased, alongside broad effects on collagen synthesis and tissue remodeling. It is worth being precise about what this means, though. It is a screen of cells in culture, not a measurement taken in a living body, and the distance between those two things is considerable. What the data does establish clearly is that the copper is not incidental — the complex behaves differently from the bare peptide and from other copper complexes, so the specific coordination chemistry is doing real work rather than simply delivering a metal.

Technical description

GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, isolated originally from human plasma. The peptide coordinates Cu²⁺ with high affinity through the imidazole nitrogen of histidine, the N-terminal amine, and backbone amide nitrogens, forming a square-planar complex.

Reported activity includes stimulation of collagen and glycosaminoglycan synthesis in fibroblasts, modulation of metalloproteinase and TIMP expression, and antioxidant activity attributed in part to copper-dependent superoxide dismutase-like behavior. The complex additionally functions as a physiological copper shuttle, and separating copper-delivery effects from direct peptide effects remains an open methodological question in the literature.

Transcriptomic characterization derives principally from analysis of Broad Institute Connectivity Map data, in which GHK was reported to alter expression by greater than 50% in approximately 32% of assayed human genes, commonly summarized as over 4,000 genes. Affected categories include DNA repair (reported as 47 genes upregulated against 5 downregulated), extracellular matrix remodeling, antioxidant response, and inflammatory signaling. These findings are derived from cultured cell line expression profiling rather than in vivo measurement, and should be interpreted within that methodological limitation. Primary references: Pickart & Margolina, Int J Mol Sci 2018;19(7):1987 (PMID 29986520); Pickart et al., Biomed Res Int 2014;2014:151479.

Regulatory status

GHK-Cu is used as a cosmetic ingredient in topical formulations, where it is regulated as a cosmetic rather than a drug. It is not an FDA-approved drug for any therapeutic indication. Material supplied for laboratory research is not a cosmetic product and is not manufactured, tested, or released under pharmaceutical or cosmetic-grade standards.