GHK-Cu carries copper, rebuilds matrix, and reshapes gene expression — here is what the literature actually measured.

What the GHK-Cu record establishes

GHK-Cu is glycyl-L-histidyl-L-lysine chelated to a single copper(II) ion — a copper-binding tripeptide first isolated from human plasma in 1973, when it was identified as the factor that made aged human liver tissue synthesize proteins like younger tissue ^[5][6]. In fibroblast culture it stimulates collagen synthesis at picomolar-to-nanomolar concentrations, with onset between 10^-12 and 10^-11 M and a peak near 10^-9 M, and it does so without changing cell number — a specific metabolic effect, not a proliferation artifact ^[1]. Across the published gene-expression analyses it modulates roughly 31.2% of human genes at a 50%-or-greater change threshold, raising 59% of those and suppressing 41% ^[2]. That breadth, and the neuroprotection studies that follow from it, are what this brief reads.

The compound sits in two regulatory worlds at once. As Copper Tripeptide-1 — its cosmetic-ingredient (INCI) name — it is a legal topical ingredient with a long safety record. As an injectable or systemic agent it is an unapproved research chemical with no validated human pharmacokinetics ^[6]. This site keeps the two separate, and frames every dose in the species and model it was studied in.

The brief is organized so each strand can be read on its own terms. The GHK-Cu research findings page sets out the mechanism and the matrix, gene, and inflammation data; the GHK-Cu research doses page reports what was administered to which species; and the GHK-Cu safety and regulatory status is laid out plainly in the question set. For the strongest controlled human signal, see the copper peptide hair growth studies; for the differentiating preclinical angle, see the GHK-Cu neuroprotection research.

What 'copper peptide' means in the GHK-Cu literature

A copper peptide is a short amino-acid chain that binds a copper(II) ion and carries it into tissue as a chaperone while acting as a signaling molecule in its own right. GHK-Cu is the archetype of the category: three residues — glycine, histidine, lysine — coordinating one copper ion through the histidine imidazole nitrogen, the glycine alpha-amino nitrogen, and a deprotonated amide nitrogen, with the lysine side chain left free ^[6]. The copper is not incidental. Copper coordination is required for most documented activities; the free GHK peptide does not reproduce MMP-2 stimulation in fibroblast cultures ^[6].

That distinction matters for reading the literature, because many studies use the free tripeptide and report systemic or gene-level effects while others use the copper chelate. The difference between GHK and GHK-Cu is the first thing a careful reader needs to fix in mind, and this brief flags which form each study used.

GHK copper peptide: the endogenous tripeptide behind the research

GHK copper peptide is not a synthetic invention; the GHK sequence occurs endogenously, embedded in the alpha-2(I) chain of type I collagen and in the matricellular protein SPARC/osteonectin, and it circulates as a free factor in human plasma, saliva, and urine ^[5][6]. Tissue injury liberates it from collagen, where it then drives local repair — the foundational reason GHK behaves as a wound-response signal rather than a foreign drug.

The endogenous pool falls with age. Plasma GHK declines from approximately 200 ng/mL (about 10^-7 M) at age 20 to approximately 80 ng/mL by age 60 ^[3]. That age-related decline is the empirical hook behind the compound's anti-aging hypothesis — and, read honestly, it is a correlation in search of a clinical outcome rather than proof of one. The skin-regeneration literature treats the GHK copper peptide as a multi-pathway matrix modulator: it stimulates collagen, dermatan sulfate, chondroitin sulfate, and the proteoglycan decorin in study models ^[3].

What makes the molecule unusual is reach. Across gene-expression analyses GHK modulates roughly 31.2% of human genes at a 50%-or-greater change threshold, with 59% raised and 41% suppressed, and it concentrates that effect on repair-relevant programs — strongly upregulating the ubiquitin-proteasome system, DNA-repair genes, and antioxidant gene sets while suppressing NF-kB-driven inflammation ^[2]. That a three-amino-acid peptide reaches so far into the transcriptome is the reason the same compound shows up in the skin, wound-healing, hair, and neuroprotection literatures alike — and the reason this brief treats the breadth itself as a finding worth stating plainly, rather than a claim to wave past ^[2][6].

Copper Tripeptide-1: the INCI name for GHK-Cu

Copper Tripeptide-1 is the INCI (International Nomenclature of Cosmetic Ingredients) name for GHK-Cu — the label term, written on a skincare ingredient list as copper tripeptide-1, used to declare copper-peptide content ^[6]. Where a product lists "Copper Tripeptide-1," the research name is GHK-Cu and the compound is the same copper(II) chelate (CAS 89030-95-5, molecular weight 402.92 Da) discussed throughout this brief.

The naming split is worth holding onto because it tracks the regulatory split. Under the Copper Tripeptide-1 label, the ingredient is legally marketed in topical cosmetics across the US, EU, and UK; under the GHK-Cu research name, injectable and systemic formulations have no approved regulatory pathway ^[6]. One molecule, two names, two very different evidence bases — and this site reads each against its own data, never letting the long topical safety record of the cosmetic ingredient stand in for evidence the systemic research peptide does not yet have ^[6].

What does a GHK-Cu peptide do?

What does a GHK-Cu peptide do?

GHK-Cu is a copper-binding tripeptide that, in research models, stimulates fibroblast synthesis of collagen, elastin, and glycosaminoglycans, modulates matrix metalloproteinases against their TIMP inhibitors, supports angiogenesis through VEGF and FGF-2, and acts as a broad gene-expression modulator and antioxidant ^[3][6]. It works at picomolar-to-nanomolar concentrations, behaving as both a copper chaperone and a signaling molecule ^[2].

What is GHK-Cu and how does it work?

GHK-Cu is glycyl-L-histidyl-L-lysine chelated to copper(II); it acts as both a copper chaperone and a signaling molecule, driving matrix-synthesis and repair-gene programs at picomolar-to-nanomolar concentrations in study models ^[1][2]. The copper ion additionally enables lysyl-oxidase-mediated collagen and elastin cross-linking and a superoxide-dismutase-like antioxidant activity ^[6].

What is the difference between GHK and GHK-Cu?

GHK is the free tripeptide (molecular weight 340.38 Da); GHK-Cu is its copper(II) chelate (molecular weight 402.92 Da) ^[6]. Copper coordination is required for most documented tissue-repair activities, including MMP-2 stimulation, which the free peptide does not reproduce in fibroblast cultures ^[6]. This brief notes which form each cited study used, because the two are frequently conflated.