LIVE RESEARCH METRICS / COPPER TRIPEPTIDE-1
GHK-Cu is a copper tripeptide whose mechanism runs from copper coordination to genome-wide gene expression.
A metrics-first reading of the copper-tripeptide literature, traced as a pipeline: the copper(II) complex, the signaling layer it drives, the matrix it builds — and the human-data gap left honest.
GHK-Cu, in one pass
GHK-Cu is the glycyl-L-histidyl-L-lysine copper(II) complex — a copper-binding tripeptide (Gly-His-Lys) chelated 1:1 to a copper(II) ion, molecular weight 402.92 Da, CAS 89030-95-5. It occurs naturally in human plasma, saliva, and urine, and the GHK sequence is carried inside type I collagen and SPARC/osteonectin, released when those proteins break down [5][6]. Loren Pickart first isolated it in 1973 as a plasma factor that made aged human liver tissue synthesize protein like younger tissue, and plasma GHK declines from roughly 200 ng/mL at age 20 to about 80 ng/mL by age 60 [4].
The single finding that organizes everything below: in human fibroblast cultures, GHK-Cu stimulated collagen synthesis beginning between 10^-12 and 10^-11 M, peaking near 10^-9 M, with no change in cell number — a specific metabolic signal, not simple proliferation [1]. At the genome scale, gene-expression analysis reports GHK alters about 31.2% of human genes at a 50%-or-greater change threshold, upregulating wound-repair, DNA-repair, antioxidant, and protein-quality-control programs [3]. This site reads that record as a pipeline — copper coordination first, the signaling layer next, matrix synthesis after, the gene readout last — and marks the place the pipeline stops: there is no validated human pharmacokinetic data for systemic GHK-Cu [4].
What a copper peptide is
A copper peptide is a short amino-acid chain that binds a copper ion through several coordination sites at once. In GHK-Cu, the copper(II) is held by the histidine imidazole nitrogen, the glycine alpha-amino nitrogen, and the deprotonated glycine-histidine amide nitrogen, leaving the lysine side chain free. That arrangement gives the complex a very high copper stability constant (log K ~16.4), far higher than the free peptide, which keeps copper from circulating as a loose pro-oxidant [5].
The distinction matters for function. Copper coordination is required for most of the documented activity: GHK-Cu stimulates matrix metalloproteinase-2 expression in fibroblast cultures, and the free GHK tripeptide alone does not reproduce that effect [2]. So a "copper peptide" here is not just a peptide that happens to carry copper — it is a complex whose biology is copper-dependent. The same chelation that stabilizes the metal is what lets it serve as a cofactor for lysyl oxidase and for superoxide-dismutase-like antioxidant activity [5].
GHK copper peptide: what the research describes
The GHK copper peptide record is broad but uneven, and reading it as a pipeline keeps the strong steps separate from the thin ones. The mechanistic and in-vitro layer is the strongest: dose-resolved collagen synthesis [1], copper-dependent MMP-2 regulation [2], and a genome-wide expression signature [3] are all reproducible cell-level findings. The angiogenesis story has an endogenous anchor — proteolysis of SPARC releases copper-binding peptides including GHK and KGHK that stimulate new vessel formation [6].
The tissue-engineering layer is active and recent: GHK-modified alginate drives dose-dependent VEGF secretion from human mesenchymal stem cells [13], a photo-crosslinkable hyaluronic-acid hydrogel embedded with GHK peptide nanofibers accelerated wound healing with denser collagen and stronger angiogenesis than non-lipidated GHK or EGF comparators [12], and GHK-Cu-coated scaffolds improved human dermal fibroblast viability while showing antibacterial activity against E. coli and S. aureus [14]. The copper peptide skin research and wound-healing studies carry those threads in full. The human layer is the narrowest step — small topical dermatology trials and one 45-patient combination hair-loss study [7] — and there is no validated systemic pharmacokinetic data closing the pipeline [4]. For the molecular detail, see how GHK-Cu works.
Copper Tripeptide-1 (the INCI name)
Copper tripeptide-1 is the INCI (International Nomenclature of Cosmetic Ingredients) name for GHK-Cu — the label term used to declare copper-peptide content in skincare. PubChem CID 71587328, FDA UNII 6BJQ43T1I9, DrugBank DB14683. Under that name it has a long cosmetic-ingredient safety record in topical products across the US, EU, and UK.
Naming precision is worth one sentence because the literature conflates two molecules. GHK is the free tripeptide (MW 340.38, CAS 49557-75-7); GHK-Cu, or copper tripeptide-1, is its copper(II) chelate (MW 402.92, CAS 89030-95-5). Many studies dose the free peptide and report systemic or gene-level effects, while the matrix-remodeling activity is copper-dependent [2]. Which form a given study used changes what its result means — the GHK-Cu mechanism of action page keeps that line drawn.