Introduction
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (GHK). It is one of the most frequently studied small peptides in the cell-biology and biomaterials literature and appears widely in in vitro and laboratory-model investigations. This article summarizes how the peer-reviewed research literature characterizes the compound at a molecular level. It is provided strictly as a laboratory reference and makes no statement about use in humans or animals.
FYH Peptides supplies GHK-Cu as a lyophilized, HPLC-verified research compound. The discussion below describes published research and is not a claim by FYH Peptides regarding any outcome.
Origin and Classification
GHK was first described as a small peptide isolated from human plasma fractions. In the literature it is classified as an endogenous matrikine — a short peptide associated with the extracellular matrix — and its measured concentration in biological samples is reported to decline with age. The research-grade material supplied today is produced entirely by chemical synthesis and is not extracted from any biological source.
The free peptide (GHK) binds copper(II) ions with high affinity. When complexed with copper it is referred to as GHK-Cu. Much of the published research concerns the copper complex specifically, because the copper coordination is central to the chemistry the literature investigates.
Structure and Copper Coordination
The sequence of GHK is Gly-His-Lys, with a reported molecular weight near 340.4 g/mol for the free tripeptide. In the copper complex, the imidazole nitrogen of the histidine residue and the N-terminal amine are described as principal coordination sites for the Cu(II) ion. This copper coordination gives concentrated GHK-Cu solutions their characteristic blue color, a detail frequently noted in analytical and handling descriptions.
Pathways Described in the Research Literature
A number of in vitro and laboratory-model studies have examined processes associated with GHK and GHK-Cu. The following are reported in the literature as areas of investigation; they are listed here for reference and do not represent established conclusions or any claim of effect:
- Extracellular-matrix research, including studies of collagen and glycosaminoglycan synthesis in cultured fibroblasts.
- Copper transport and delivery, where the peptide is studied as a copper-binding ligand in cell-culture and chemistry models.
- Antioxidant and metal-chelation chemistry, examined in biochemical assays.
- Gene-expression modulation, reported in transcriptomic studies that describe broad changes in gene activity in treated cell cultures.
- Angiogenesis-related and tissue-remodeling signaling, studied in cell and tissue-model systems.
In every case the literature describes laboratory observations. Readers should consult the original publications, linked in the Published Research section below, rather than relying on any summary.
In Vitro Research Applications
Within laboratory research, GHK-Cu appears in fibroblast culture studies, scratch-wound closure models performed on cultured cells, skin-equivalent and extracellular-matrix model systems, and biomaterials research where the peptide is studied as a surface or scaffold coating. These are bench experiments conducted on cells, tissues, or materials, not investigations of any living human subject.
Analytical Characterization
Research-grade GHK-Cu is typically supplied lyophilized and is characterized by reversed-phase HPLC for purity, with mass spectrometry used to confirm identity. Because the material is a copper complex, a complete Certificate of Analysis should make clear whether the reported figure describes the copper complex (GHK-Cu) or the free peptide (GHK). FYH Peptides reports batch-specific HPLC purity on each Certificate of Analysis. Lyophilized peptide is generally stored at -20 °C and protected from light and moisture, consistent with standard laboratory handling of synthetic peptides. See the GHK-Cu compound data page for the current lot's analytical figures.
GHK vs GHK-Cu: A Note on Nomenclature
The literature discusses both the free tripeptide (GHK, sometimes called the apo-peptide) and its copper complex (GHK-Cu). The two are chemically distinct, and studies are not always interchangeable between them. When evaluating a research report or a Certificate of Analysis, confirm which form is described, since the copper content is part of what the analytical figures characterize.
Summary
GHK-Cu is the copper(II) complex of the tripeptide Gly-His-Lys, classified in the literature as an endogenous matrikine and widely used as a model compound in extracellular-matrix, copper-chemistry, and gene-expression research. The pathways above reflect areas that published authors have chosen to investigate. None of this content describes or supports any application in humans or animals.
Published Research
Selected peer-reviewed literature indexed on NCBI PubMed. Listed for laboratory reference only — FYH Peptides makes no claim regarding the conclusions of any cited author.
- 1. The potential of GHK as an anti-aging peptide. Dou Y, Lee A, Zhu L, et al. · Aging pathobiology and therapeutics · 2020 PubMed · DOI
- 2. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Pickart L, Margolina A · International journal of molecular sciences · 2018 PubMed · DOI
- 3. Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective. Mortazavi SM, Mohammadi Vadoud SA, Moghimi HR · BioImpacts : BI · 2025 PubMed · DOI
- 4. The glycyl-l-histidyl-l-lysine-Cu(2+) tripeptide complex attenuates lung inflammation and fibrosis in silicosis by targeting peroxiredoxin 6. Bian Y, Deng M, Liu J, et al. · Redox biology · 2024 PubMed · DOI
- 5. Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions. Rahman OF, Lee SJ, Seeds WA · Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews · 2026 PubMed · DOI