The short version of Copper(II) fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-08-10 and is reviewed periodically as new material appears.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide sequence is often abbreviated Gly-His-Lys, and the copper is bound through the histidine imidazole nitrogen and adjacent peptide nitrogens. The complex is frequently described as a 1:1 peptide-to-copper species. It occurs naturally in human plasma, saliva, and urine at low concentrations. Its endogenous levels have been reported to decline with age, although the precise physiological role of that change remains an open question.
Research interest in GHK-Cu centers on its ability to deliver copper and to influence cellular processes in laboratory models. In cell culture and animal studies, the complex has been linked to collagen synthesis, antioxidant enzyme activity, and expression of genes associated with tissue remodeling. These effects are not equivalent to proven clinical outcomes. The mechanisms proposed include copper transfer to cuproenzymes, modulation of growth factor signaling, and interactions with extracellular matrix components. How much of the observed activity depends on intact GHK-Cu versus free copper or free peptide is not fully resolved.
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, a short sequence of three amino acids. The peptide was first isolated from human plasma in 1973 during research on factors that influence tissue repair in liver. Its ability to bind copper ions became a central point of interest because the metal changes the peptide's chemistry and its behaviour in laboratory systems. Today the compound appears in cosmetic formulations, cell-culture studies, and biochemistry literature under several names.
The peptide sequence places a histidine in the middle, and this residue dominates metal binding. Copper(II) coordinates through the imidazole nitrogen of histidine and the terminal amino group, forming a stable chelate ring system. Loss of the copper ion leaves the free tripeptide, which has different solubility and reactivity. This structural detail matters because assays that measure only the peptide backbone can miss whether copper is still bound to it.
Several names circulate for the same material, which complicates literature searches. Cosmetic ingredient lists often use copper tripeptide-1, while older biochemistry papers use glycyl-L-histidyl-lysine or its abbreviation GHK. The copper complex is sometimes written as GHK-Cu(II) to make the oxidation state explicit. Terminology is not fully standardized, so matching a compound across sources requires attention to the exact sequence, the counterion, and the stated copper content. Reviews that compare studies must account for these naming differences before drawing conclusions.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper-binding tripeptide complex | Includes Gly-His-Lys and Cu(II) |
| Molecular formula | C14H22CuN6O4 | Reported for the 1:1 complex |
| Appearance | Blue to blue-violet solid | Color arises from copper d-d transitions |
| Solubility class | Water-soluble; slightly soluble in polar organic solvents | Often prepared as aqueous stock |
| Typical storage | -20 °C, desiccated, protected from light | Limits oxidation and moisture uptake |
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and copper(II). The peptide sequence consists of glycine, histidine, and lysine, and its imidazole and amino groups provide binding sites for the metal ion. In the complex, copper is held through nitrogen donors from the histidine side chain, the N-terminal amine, and deprotonated amide nitrogens. The resulting compound is intensely blue and water-soluble. It occurs naturally in human plasma, saliva, and urine at low concentrations.
The peptide was first isolated from human albumin in 1973 by Loren Pickart, who later described its copper-binding behavior. Early work linked the complex to wound healing and tissue remodeling. Plasma levels of GHK decline with age, a pattern that stimulated interest in topical and supplemental applications. Researchers have reported that the tripeptide influences collagen synthesis, antioxidant defense, and inflammatory signaling in cell and animal models. Human clinical evidence remains limited and often relies on small studies.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide backbone consists of glycine, histidine, and lysine joined in that order. Copper is held through the imidazole nitrogen of histidine and the alpha-amino group at the N-terminus, which together produce a square-planar arrangement around the metal center. The solid appears blue to violet, a color that originates from d-d electronic transitions within the copper coordination sphere. The complex is indexed under CAS number 89030-95-5.
The sequence now called GHK was first reported in the early 1970s after isolation from human plasma, where it was noted to influence liver cell behavior in laboratory preparations. Later work described a copper-binding form and its activity in fibroblast and wound-model experiments. Review articles frequently group the substance with other copper peptides. Concentrations in blood appear to fall with age in several small surveys, although the reason for this trend is not settled. Whether such a decline carries functional consequences remains an open question.
GHK-Cu is the copper-binding complex formed by the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The free peptide is usually written as GHK, and the complex is written as GHK-Cu or Cu-GHK. The sequence was identified in human plasma and later detected in saliva and urine. Its name comes from the single-letter codes of glycine, histidine and lysine. The complex is widely described as a naturally occurring carrier of copper in blood rather than as a free peptide with its own hormonal role.
Copper binds to the peptide through the histidine imidazole nitrogen and the terminal amino group, forming a stable square-planar complex. Binding constants reported for copper(II) with GHK are high, so the peptide competes effectively for copper in solution. The complex absorbs visible light, which gives solutions a blue to violet colour. Whether the metal-free peptide has a distinct biological function of its own is still an open question; some work treats it mainly as a copper delivery vehicle, while other work reports peptide-specific effects.
Characterizing GHK-Cu requires methods that distinguish the intact complex from free peptide and unbound copper. UV-visible absorption around 600 nm provides a rapid check for copper coordination, while circular dichroism reports on peptide secondary structure. Mass spectrometry confirms the peptide mass and can detect copper adducts under carefully controlled conditions. Electron paramagnetic resonance is particularly informative for Cu(II) because it reveals the ligand field symmetry. No single technique fully defines the complex, so laboratories combine orthogonal methods.
Stability of GHK-Cu in solution depends on pH, temperature, buffer composition, and oxygen exposure. The copper center can undergo reduction or dissociation, especially in the presence of strong metal chelators such as EDTA. Aqueous solutions are often prepared fresh or stored frozen to limit degradation. Lyophilized solid is more stable than liquid formulations, but it can absorb moisture and should be kept dry. Light exposure may also affect copper complexes, though the effect is often modest.
== History == Zealand Pharma A/S was founded by Bjarne Due Larsen, Lars Hellerung Christiansen, Leif Helth Jensen, Dan Buxbom, and Florian Schönharting in 1997 as Peptide Probe Technologies ApS, a biopharmaceutical company focused on the design and development of peptide-based medicine. In 1998, the company changed its name to Zealand Pharma ApS following the addition of several new members, including Eva Steiness and former Lundbeck personnel. Eva Steiness was appointed CEO when the company was restructured into a stock corporation, Zealand Pharma A/S, in the spring of 1999. In 2005, Zealand Pharma tried to be listed on the stock exchange, but had to resign for want of interest from investors. In 2010, they finally succeeded in being listed, and the stocks are now traded at the Copenhagen Stock Exchange (NASDAQ OMX København). On January 15, 2015, Britt Meelby Jensen acquired the position as CEO from David Solomon, who had led the company during the years 2008–2014. In February 2019, Jensen left her position, and in April 2019, Emmanuel Dulac was chosen and inaugurated as CEO. Dulac has worked both European and American companies within the pharmaceutical industry. In September 2019, the Dutch family foundation Van Herk Investments injected 560 million Danish Kroner (approx. 64 million pound sterling) into Zealand Pharma, which means the foundation owns a fifth of the company's shares. In October 2019, Zealand Pharma bought up the Canadian biotechnology company Encycle Therapeutics. On March 30, 2022, Dr. Adam Steensberg assumed the position of Chief Executive Officer.
== As a drug target == The oxoglutarate dehydrogenase complex (α-ketoglutarate dehydrogenase complex) is responsible for converting AKG into succinyl-CoA in the citric acid cycle. It is one of the rate-limiting enzymes in the cycle. In breast cancer with lung metasatsis models, inhibiting this enzyme (causing an accumulation of AKG) reduces cancer cell growth; a similar effect is observed with AKG supplementation in mice with B-cell lymphoma. On the other hand, a dysfunction of this enzyme (again causing AKG accumulation) leads to increased lipid peroxidation in CHCHD2-linked Parkinson's disease models and appears to be partly responsible for elevated phosphorylated α-synuclein levels, as improving the function of this complex causes both AKG and phosphorylated α-synuclei to decrease.
1993/3083) Friendly Societies Act 1992 (Transitional and Consequential Provisions) Regulations 1993 (S.I. 1993/3084) Welfare of Animals at Markets (Amendment) Order 1993 (S.I. 1993/3085) Diseases of Animals (Approved Disinfectants) (Amendment) (No. 2) Order 1993 (S.I. 1993/3086) Civil Aviation (Route Charges for Navigation Services) (Second Amendment) Regulations 1993 (S.I. 1993/3098)
Sources: en.wikipedia.org
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== Girls' opportunities == Save the Children UK's Every Last Girl 2016 report includes a "Girls' Opportunity Index" which ranks nations on five indicators of girls' well-being: child marriage; adolescent fertility; maternal mortality; secondary school completion; number of female MPs. Thailand ranked 81 of 144 nations (1=best, 144=worst). Other ASEAN nations ranked were: Vietnam, 47; Philippines, 64; Indonesia, 73; Bhutan, 80; Cambodia, 89; and Laos, 101.
==== Mixed bed deionization ==== Mixed bed deionization is a 40/60 mixture of cation and anion resin combined in a single ion-exchange column. With proper pretreatment, product water purified from a single pass through a mixed bed ion exchange column is the purest that can be made. Most commonly, mixed bed demineralizers are used for final water polishing to clean the last few ions within water prior to use. Small mixed bed deionization units have no regeneration capability. Commercial mixed bed deionization units have elaborate internal water and regenerant distribution systems for regeneration. A control system operates pumps and valves for the regenerants of spent anions and cations resins within the ion exchange column. Each is regenerated separately, then remixed during the regeneration process. Because of the high quality of product water achieved, and because of the expense and difficulty of regeneration, mixed bed demineralizers are used only when the highest purity water is required.
Sources: en.wikipedia.org
GHK-Cu is a complex of the tripeptide glycyl-L-histidyl-L-lysine with copper(II). The peptide binds copper through its histidine residue and neighboring amide nitrogens, forming a stable coordination compound. It is studied as a research chemical and used in some cosmetic formulations.
Yes, the peptide and its copper complex have been detected in human plasma, saliva, and urine. Endogenous concentrations are low, and reported levels change with age and physiological state. The biological significance of those changes is still an active area of study.
GHK refers to the free tripeptide without a bound copper ion. GHK-Cu contains copper(II) coordinated to the same peptide backbone. The presence of copper affects the complex's color, stability, and interaction with biological molecules.
The peptide is glycyl-L-histidyl-L-lysine, a three-amino-acid sequence commonly abbreviated GHK. It binds a single copper(II) ion under typical laboratory conditions. The free peptide and the copper complex are separate chemical species with different properties.