GHK-Cu is a natural copper complex of the tripeptide glycyl-L-histidyl-L-lysine (Gly-His-Lys), first isolated from human blood plasma by the biochemist Loren Pickart in 1973. The free GHK peptide has a high affinity for copper(II) ions and, in biological media, spontaneously forms a 1:1 complex that, in dry form, has a characteristic blue-violet colour[1][4].
The plasma concentration of GHK falls with age: from roughly 200 ng/mL at 20 years to about 80 ng/mL at 60. This decline coincides with the observed drop in tissue regenerative capacity, which is what drew the attention of researchers in ageing and repair[2].
What it is and its class
GHK-Cu belongs to the copper-binding signalling peptides. Chemically it is a coordination complex in which the tripeptide Gly-His-Lys acts as a ligand for the Cu²⁺ cation: the imidazole nitrogen of histidine, the amino group of glycine, and a deprotonated peptide nitrogen form a stable chelate. The free tripeptide has the formula C₁₄H₂₄N₆O₄ and a molar mass of about 340.4 g/mol, while the copper complex is about 403.9 g/mol[3]. In INCI (International Nomenclature of Cosmetic Ingredients) cosmetic nomenclature the compound is designated Copper Tripeptide-1. It is important to distinguish the CAS (Chemical Abstracts Service) registration number of the free peptide (49557-75-7) from that of the copper complex (89030-95-5), since the literature and catalogues often confuse them.
Mechanism of action
Historically the action of GHK-Cu was explained mainly through the transport and bioavailability of copper, a required cofactor for lysyl oxidase, superoxide dismutase, and other enzymes of remodelling and antioxidant defence[4]. Later gene-expression data widened this picture: in cell cultures GHK changes the activity of a substantial share of human genes, in particular those responsible for the stress and injury response, extracellular matrix remodelling, and inflammation[1]. At the tissue level the peptide is described as stimulating the synthesis of collagen, glycosaminoglycans (dermatan and chondroitin sulfate), and the small proteoglycan decorin, while modulating the balance of matrix metalloproteinases and their inhibitors[2]. There are also reports of effects on fibroblasts and basal epidermal cells with increases in "stemness" markers (p63, integrins)[2].
What the research shows
The main body of published data consists of preclinical in vitro and animal-model work, along with review articles. The directions studied include: wound healing and contraction and improved epithelialisation; stimulation of growth-factor production and antioxidant-enzyme activity; dermal remodelling and effects on the synthesis of extracellular matrix components[3]. Some reviews summarise data on anti-inflammatory and potentially antineoplastic effects of copper peptides in model systems[3]. It should be stressed that this is mainly mechanistic and preclinical research: large controlled clinical trials that would clearly establish clinical efficacy are still lacking, and some results were obtained under specific experimental conditions[1][2].
Form and handling (research-use)
Longeva supplies GHK-Cu strictly as a research substance (reagent) with a certificate of analysis (COA). It is not a medicine. The typical form is a lyophilised blue-violet powder, stored protected from light and moisture at low temperature (usually around −20 °C for long-term storage). Reconstituted solutions are prepared immediately before an experiment; the copper complex is sensitive to redox conditions and pH, so the solvent and buffer are chosen for the specific protocol. All handling should be carried out in laboratory conditions by qualified personnel following reagent-handling rules. The material is intended only for research and analytical use and is not used for diagnosis or treatment.