# GHK-Cu: The Copper-Peptide Research, Annotated Study by Study

> GHK-Cu is the copper(II) chelate of glycyl-histidyl-lysine. It stimulates fibroblast collagen synthesis at picomolar doses and shifts roughly 31% of human genes toward repair. A hand-annotated reading of the literature.

The copper(II) chelate of glycyl-histidyl-lysine, read out of the published record: the picomolar collagen dose-response, the gene-modulation data, the anti-inflammatory signal, and the gaps left visible in the margin.

## What this notebook records about GHK-Cu

GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, and in cell culture it stimulates dermal fibroblasts to synthesize collagen at picomolar concentrations — the increase begins between 10⁻¹² and 10⁻¹¹ M, peaks near 10⁻⁹ M, and occurs with no change in cell number, marking a specific metabolic effect rather than simple proliferation [1]. That single finding, published in 1988, is the seed clipping for everything pasted onto the pages that follow. The molecule is endogenous: it was first isolated from human plasma in 1973 as the factor that made aged liver tissue synthesize proteins like younger tissue, and plasma GHK declines from roughly 200 ng/mL at age 20 to about 80 ng/mL by age 60 [3]. This is a research digest. It annotates what the studies measured; it does not prescribe anything, sell anything, or speak for a clinic.

The GHK sequence sits inside the alpha-2(I) chain of type-I collagen, so the body liberates it during tissue injury [6]. Chelated to copper, it carries that metal where lysyl oxidase needs it for collagen and elastin cross-linking, and it behaves as a pleiotropic signaling peptide on top of its chaperone role [3]. The dealt lens of this page is the [GHK-Cu and inflammation](/faq) thread — the NF-kB suppression and lowered cytokines documented across the fibrosis and colitis models [7][14]. The skin work, the hair-count trial, the gene maps, and the honest copper-handling caveats all get their own clippings below and on the inner pages.

## GHK Copper Peptide: What the Research Describes

GHK copper peptide is the copper-bound form of glycyl-histidyl-lysine, and across more than three decades of study it has shown a consistent profile: matrix synthesis up, oxidative damage down, and a broad transcriptomic shift toward repair. Gene-expression analysis reports that GHK alters expression of about 31.2% of human genes at a 50%-or-greater change threshold — 59% of those up, 41% down — with strong stimulation of the ubiquitin-proteasome system (41 genes up, 1 down) plus DNA-repair and antioxidant gene sets [2]. In a foundational tissue-remodeling review, GHK-Cu increased synthesis of collagen, elastin, metalloproteinases, anti-proteases, VEGF, FGF-2 and nerve growth factor while suppressing free radicals, TGF-beta-1, TNF-alpha and protein glycation [6]. The copper coordination is not incidental: the free peptide does not reproduce MMP-2 stimulation in fibroblasts, so which form a study used determines what it can claim [6].

## What a Copper Peptide Is

A copper peptide is a short amino-acid chain bound to a copper(II) ion, and GHK-Cu is the most-studied example: three residues — glycine, histidine, lysine — wrapped around one copper atom through the histidine imidazole, the glycine amino nitrogen, and a deprotonated amide nitrogen, with the lysine side chain left free. The molecular weight of the complex is 402.92 Da against 340.38 Da for the free tripeptide [6]. The copper is held tightly: the complex carries a very high stability constant (log K ~16.44), far above free GHK, which keeps the metal chelated rather than loose and reactive [9]. That tight binding is why GHK-Cu can completely block copper-dependent LDL oxidation in vitro while a free-copper system would do the opposite [9].

### Copper Tripeptide-1 (the INCI name)

Copper Tripeptide-1 is the INCI cosmetic-ingredient name for GHK-Cu — the label term that appears on copper-peptide skincare. It denotes the same glycyl-histidyl-lysine-copper(II) complex (CAS 89030-95-5) described throughout the dermatology literature [3]. Topical Copper Tripeptide-1 is a legal cosmetic ingredient in the US, EU and UK; the [copper peptide side effects](/side-effects) and tolerability record is read on its own page. Injectable or systemic GHK-Cu is unapproved and research-only, a distinction the notebook keeps explicit.

## Questions the literature answers about GHK-Cu

Three definitional questions recur often enough to belong on the front page; the full set lives on the FAQ.

### What is GHK copper peptide?

GHK copper peptide is glycyl-histidyl-lysine chelated 1:1 to copper(II) — molecular formula C14H23CuN6O4⁺, molecular weight 402.92 Da [3]. It occurs endogenously in human plasma, saliva and urine and within type-I collagen, and it acts as both a copper chaperone and a signaling peptide that stimulates matrix synthesis and antioxidant and DNA-repair gene programs [2][6].

### What is GHK-Cu and how does it work?

GHK-Cu is the glycyl-histidyl-lysine tripeptide chelated to copper(II), and it works by delivering copper for lysyl-oxidase cross-linking and superoxide-dismutase-like antioxidant activity while modulating wound-repair, DNA-repair and antioxidant gene programs — about 31.2% of human genes at a ≥50% change threshold [2]. In fibroblasts it raises collagen synthesis at picomolar-to-nanomolar concentrations without changing cell number [1].

### What does a GHK-Cu peptide do?

In research models GHK-Cu acts as a copper chaperone and signaling peptide: it stimulates fibroblast synthesis of collagen, elastin and glycosaminoglycans, rebalances matrix metalloproteinases against their TIMP inhibitors, and drives angiogenic and antioxidant repair programs [3][6]. The copper-dependence is documented — the free peptide alone does not reproduce the MMP-2 effect [6].

### What is the difference between GHK and GHK-Cu?

GHK is the free tripeptide (MW 340.38); GHK-Cu is its copper(II) chelate (MW 402.92). Copper coordination is required for most documented tissue-repair activity — the free peptide does not reproduce MMP-2 stimulation in fibroblasts — so the form a study used matters when reading its result [6].

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A hand-bound studio notebook of the GHK-Cu copper-peptide literature — every collagen, gene, and hair-count clipping pasted in and sourced to its paper, the honest gaps left in the margin, with nothing here prescribed, dispensed, or for sale.