# GHK-Cu: A Living Digest of the Copper-Peptide Research > GHK-Cu is a copper-binding tripeptide that stimulates collagen synthesis in fibroblasts, drives VEGF-mediated angiogenesis, and shifts roughly 31% of human genes toward repair. A cited reading room. A bright, cited digest of what the published literature has actually grown — the collagen dose-response, the gene-expression signature, the angiogenesis data, and the honest gaps — with every quantitative claim sourced. ## What the GHK-Cu literature describes GHK-Cu is a copper-binding tripeptide that, in study models, makes aged tissue behave more like young tissue. It stimulates dermal fibroblasts to synthesize collagen, elastin, and glycosaminoglycans [1][6], drives VEGF- and FGF-2-mediated angiogenesis during wound repair [6][7], supports hair-follicle activity [4], and shifts roughly 31% of human genes toward DNA-repair, antioxidant, and tissue-remodeling programs [2]. It was first isolated from human plasma by Loren Pickart in 1973 as the factor that caused aged liver tissue to make proteins like younger tissue. The molecule is glycyl-L-histidyl-L-lysine chelated 1:1 to a copper(II) ion. Its molecular weight is 402.92 Da; its CAS number is 89030-95-5; its cosmetic-ingredient name is Copper Tripeptide-1. The GHK sequence is not foreign chemistry — it occurs naturally inside the alpha-2(I) chain of type I collagen and in the matrix protein SPARC, and it circulates in human plasma, saliva, and urine. Plasma GHK declines with age, from about 200 ng/mL at 20 years to about 80 ng/mL by 60 [3]. This site reads that record plainly. The strongest evidence is preclinical and topical-cosmetic; the controlled human data are thinner, and we name where they stop. What follows is organized by what the studies measured: [how GHK-Cu works](/research), the [copper peptide skin research](/skin-research), the [copper peptide hair growth evidence](/hair-research), and the [GHK-Cu wound-healing research](/wound-healing) that anchors much of the mechanism. ## What a Copper Peptide Is A copper peptide is a short chain of amino acids bound to a copper(II) ion, where the copper is not incidental but central to the molecule's documented activity. GHK-Cu is the archetype: three amino acids (glycine, histidine, lysine) coordinate a single copper atom through the histidine imidazole, the glycine amino nitrogen, and a deprotonated amide nitrogen, leaving the lysine side chain free. The copper does real work. It enables lysyl-oxidase-dependent cross-linking of collagen and elastin, contributes superoxide-dismutase-like antioxidant activity, and is delivered into tissue as a controlled payload rather than free, pro-oxidant copper [6]. The chelate's stability constant is very high (log K around 16.4), which is why the bound copper stays bound and does not behave like loose copper salt. ## GHK Copper Peptide: What the Research Describes The GHK copper peptide sits at the intersection of two research lineages: dermatology, where topical Copper Tripeptide-1 has decades of cosmetic use and small placebo-controlled trials, and tissue engineering, where GHK-functionalized biomaterials are tested as wound dressings and scaffolds. Across both, the recurring finding is matrix synthesis. In human fibroblast cultures, GHK-Cu stimulated collagen production at picomolar-to-nanomolar concentrations, independent of any change in cell number — a specific metabolic signal, not a growth artifact [1]. The pleiotropic profile is documented in a foundational tissue-remodeling review: GHK-Cu increases collagen, elastin, metalloproteinases and their inhibitors, VEGF, FGF-2, and nerve growth factor, while suppressing free radicals, TGF-beta-1, and TNF-alpha, and chemoattracting the macrophages and capillary cells that rebuild tissue [6]. That breadth is the reason the same molecule appears in skin, hair, and wound literatures at once. ## Researched Effects of Copper Peptides The benefits attributed to copper peptides in the literature are best read as study outcomes, not promises. In skin, GHK-Cu stimulates synthesis of collagen, dermatan and chondroitin sulfate, and decorin, with topical formulations improving density, firmness, fine lines, and wrinkle depth in small placebo-controlled trials [3]. One comparison reported topical GHK-Cu increased procollagen synthesis in about 70% of subjects, versus 50% for vitamin C and 40% for retinoic acid [3][14]. In wound models, GHK-Cu accelerates closure and angiogenesis: a 2025 food-derived GHK-Cu self-healing hydrogel reached over 95% infected-wound closure by day 12 in mice, versus about 65% in controls, while reducing IL-6 and TNF-alpha [15]. In hair research, a six-month trial of a GHK-containing topical produced significant hair-count gains over placebo [4]. Each of these is a measured endpoint in a specific model, cited and bounded. --- A greenhouse of the GHK-Cu copper-peptide literature read at golden hour — every collagen figure, hair-count delta, and gene-expression number grown straight from its source, the gaps left in plain light, and nothing here cultivated for sale.