Chemistry and evidence reference · Gly-His-Lys · Cu(II)
GHK-Cu peptide: the chemistry and the evidence
GHK-Cu peptide is the tripeptide glycyl-histidyl-lysine with a copper(II) ion bound to it. This site sets out its chemistry, every indexed study by model and route, and the limits of what those studies show, with each statement linked to its source.
By the GHK-Cu Peptide editorial team · Last reviewed November 11, 2026 · Editorial review: pending
What is GHK-Cu peptide?
GHK-Cu is the copper(II) complex of glycyl-L-histidyl-L-lysine, a three-amino-acid peptide first identified in human serum in 1977 [Schlesinger 1977]. The copper-free peptide has the formula C14H24N6O4 and a molecular weight of 340.38 g/mol [PubChem]. The peptide holds copper(II) through the glycine amine, the amide nitrogen between glycine and histidine, and a histidine imidazole nitrogen [Hureau 2011], with a conditional dissociation constant at pH 7.4 of about 7 × 10⁻¹⁴ M [Trapaidze 2012]. In cosmetic labelling it appears as copper tripeptide-1, and its nonproprietary name is prezatide copper [PubChem].
What has been studied
Molecular structure: the sequence, how copper is bound, and why four public records disagree on the formula.
Skin research: the topical trials, permeation through excised human skin, and skin-cell studies.
Collagen research: fibroblast and wound-chamber experiments measuring matrix components.
Hair research: what the hair studies actually tested, which is mostly multi-ingredient products.
Laboratory testing: HPLC, mass spectrometry, copper assays and what a certificate of analysis can and cannot show.
Regulatory position in brief
GHK-Cu is not an approved drug in the United States. FDA lists “GHK-Cu (for injectable routes of administration)” among bulk substances that may present significant safety risks in compounding, citing the potential for aggregation, peptide-related impurities and immunogenicity, and limited human safety data [FDA 2026]. Four studies were registered on ClinicalTrials.gov at our last check, none with posted results [ClinicalTrials.gov]. Detail: regulatory status.
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (GHK). GHK was identified in human serum in 1977 and binds copper(II) tightly through three nitrogen atoms. In cosmetics it is listed as copper tripeptide-1; its nonproprietary name is prezatide copper.
Is GHK the same as GHK-Cu?
No. GHK is the copper-free peptide (C14H24N6O4, 340.38 g/mol). GHK-Cu is the peptide bound to a copper(II) ion, which changes its mass, charge and chemistry. Findings for one should not be assumed for the other.
Has GHK-Cu been tested in people?
Only on the skin, and only a little. Three randomised trials of topical products are indexed in PubMed: two (1992 and 2006) found no objective difference from the comparison, one (1994) reported faster ulcer closure. No randomised human trial of GHK-Cu given by any other route is indexed.
Is GHK-Cu FDA approved?
No. FDA lists GHK-Cu for injectable routes in Category 2 of bulk substances that may present significant safety risks in compounding, citing immunogenicity risk and limited human safety data.
References
Schlesinger DH, Pickart L, Thaler MM (1977). Growth-modulating serum tripeptide is glycyl-histidyl-lysine. Experientia. PubMed 858356 · doi:10.1007/BF02002806[Chemistry, grade D]
Hureau C, Eury H, Guillot R et al. (2011). X-ray and solution structures of Cu(II) GHK and Cu(II) DAHK complexes: influence on their redox properties. Chemistry. PubMed 21780203 · doi:10.1002/chem.201100751[Chemistry, grade D]
Trapaidze A, Hureau C, Bal W et al. (2012). Thermodynamic study of Cu2+ binding to the DAHK and GHK peptides by isothermal titration calorimetry (ITC) with the weaker competitor glycine. J Biol Inorg Chem. PubMed 21898044 · doi:10.1007/s00775-011-0824-5[Chemistry, grade D]
Bishop JB, Phillips LG, Mustoe TA et al. (1992). A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers. J Vasc Surg. PubMed 1495150 · doi:10.1067/mva.1992.37086[Human, grade A]
Mulder GD, Patt LM, Sanders L et al. (1994). Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper. Wound Repair Regen. PubMed 17147644 · doi:10.1046/j.1524-475X.1994.20406.x[Human, grade A]
Miller TR, Wagner JD, Baack BR et al. (2006). Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg. PubMed 16847171 · doi:10.1001/archfaci.8.4.252[Human, grade A]
Mateescu DM, Gavrilescu DM, Mincioaga RI et al. (2026). GHK-Cu as a Bioactive Metallopeptide and Drug-Delivery Cargo: Coordination Chemistry, Formulation Science, Therapeutic Evidence, and a Translational Roadmap. Pharmaceutics. PubMed 42797253 · doi:10.3390/pharmaceutics18091077[Review, grade R]
U.S. Food and Drug Administration (2026-04-22). Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Source[retrieved 2026-11-11]
PubChem, National Library of Medicine. glycyl-L-histidyl-L-lysine (CID 73587). Source[retrieved 2026-11-11]
PubChem, National Library of Medicine. Prezatide copper (CID 71587328). Source[retrieved 2026-11-11]
U.S. National Library of Medicine, ClinicalTrials.gov. ClinicalTrials.gov search: GHK-Cu, copper peptide, copper tripeptide, glycyl-histidyl-lysine. Source[retrieved 2026-11-11]