This is a working overview of GHK-Cu, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-05 and is reviewed periodically as new material appears.
Published studies describe the complex in several research contexts, including collagen synthesis, antioxidant behaviour, and wound repair models. Much of this work is conducted in cultured cells or in small animal systems, and the findings are frequently cited in reviews of copper peptides. Direct clinical evidence in humans is comparatively limited, and reported outcomes vary with formulation and study design. Whether free chain or metal-bound form was used is not always stated, a point that complicates comparison between reports.
GHK-Cu is a coordination complex formed between the peptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The unbound chain, abbreviated GHK, consists of three amino acids and occurs naturally in human plasma, saliva, and urine. Binding of the metal is mediated mainly by the imidazole nitrogen of the histidine residue together with backbone amides, producing a stable chelate. Ingredient nomenclature often lists the same substance as copper tripeptide-1. Its charge and solubility behaviour differ from those of the metal-free chain.
The compound was first isolated from human plasma by the biochemist Loren Pickart in 1973. Early work identified it as a factor that altered the behavior of cultured liver cells, and later studies linked it to connective tissue and wound-related processes. Reported plasma concentrations fall markedly between roughly age twenty and age sixty, a pattern that generated interest in copper peptide biology. Whether that decline has functional consequences remains an open question, because differences observed across age groups do not by themselves establish causation. Research interest later expanded into cosmetic and tissue-culture settings.
Mechanistic accounts focus on how the complex delivers copper and how the released peptide interacts with the extracellular matrix. Copper is an essential cofactor for lysyl oxidase and other enzymes involved in collagen and elastin cross-linking, and GHK is one of several peptides able to carry the metal. Reported effects include altered gene expression in fibroblasts and changes in matrix metalloproteinase activity, although many of these findings come from cell culture rather than whole organisms. The relative contribution of the peptide backbone, the copper ion, and downstream copper metabolism is not fully resolved.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-lysine and a copper(II) ion. The peptide sequence is conventionally written as Gly-His-Lys, abbreviated GHK. Copper binds through the imidazole nitrogen of histidine, the alpha-amino group, and a deprotonated amide nitrogen, producing a square-planar geometry. The complex carries a net positive charge near physiological pH and is intensely blue in aqueous solution. The metal-free peptide is often written simply as GHK, while the copper-bound form is written GHK-Cu.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II) peptide complex | Coordination compound rather than a simple salt |
| Peptide sequence | Glycyl-L-histidyl-L-lysine | Abbreviated GHK in most literature |
| Molecular formula | C14H22N6O4Cu | Reported for the 1:1 complex |
| Principal binding site | Histidine imidazole nitrogen | Backbone amides contribute additional coordination |
| Common synonym | Copper tripeptide-1 | Used in ingredient and product labelling |
The compound entered scientific literature in the 1970s, when plasma factors with copper-binding activity were isolated and characterized. Later work expanded into wound healing, skin biology, and cosmetic formulation, where copper tripeptide-1 became a recognized ingredient name. Most published studies remain preclinical or small-scale, and findings are often reported in specialized dermatology or peptide journals. Regulatory treatment varies: some jurisdictions allow it as a cosmetic ingredient, while research-grade material is sold for laboratory use. Questions about optimal delivery, target tissues, and long-term effects continue to be investigated rather than settled.
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.
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.
Commercial products list GHK-Cu as copper tripeptide-1, a cosmetic ingredient. Formulators value its blue color and water solubility, which allow incorporation into serums, creams, and masks. Regulatory treatment varies: in the United States it appears in cosmetics, while some jurisdictions classify certain claims as drug-like. The compound is not an approved drug for any indication. Studies continue to examine its effects on skin, hair, and wound repair, but dosage, delivery, and long-term safety questions remain open.
The compound was first isolated from human plasma in the 1970s by Loren Pickart, who later described copper-binding activity in liver and other tissues. Early reports focused on its presence in blood and its ability to carry copper between proteins. Commercial and cosmetic use of the term 'copper peptide' has since broadened, and labels rarely distinguish GHK-Cu from other copper-binding fragments. This naming overlap makes literature searching harder, because cosmetic ingredient lists, supplier catalogues and laboratory papers use different vocabularies for the same molecule.
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.
Urocanase (also known as imidazolonepropionate hydrolase or urocanate hydratase) is the enzyme (EC 4.2.1.49) that catalyzes the second step in the degradation of histidine, the hydration of urocanic acid to imidazol-4-one-5-propionic acid. Urocanase is coded for by the UROC1 gene, located on the third chromosome in humans. The protein itself is composed of 676 amino acids which then fold, producing the final product which has two identical subunits, making the enzyme a homodimer. To catalyze the hydrolysis of urocanate in the catabolic pathway of L-histidine the enzyme utilizes its two nicotinamide adenine dinucleotide (NAD+) groups. These act as electrophiles, attaching to the top carbon of the urocanate which leads to sigmatropic rearrangement of the urocanate molecule. This rearrangement allows for the addition of a water molecule, converting the urocanic acid into imidazol-4-one-5-propionic acid.
== Developments == Due to the shortage of plutonium-238, a new kind of RTG assisted by subcritical reactions has been proposed. In this kind of RTG, the alpha decay from the radioisotope is also used in alpha-neutron reactions with a suitable element such as beryllium. This way a long-lived neutron source is produced. Because the system has a criticality close to but less than 1, i.e. Keff < 1, a subcritical multiplication is achieved which increases the neutron background and produces energy from fission reactions. Though the number of fissions produced in the RTG is very small (making their gamma radiation negligible), because each fission releases over 30 times more energy than each alpha decay (200 MeV compared to 6 MeV), up to a 10% energy gain is attainable, which translates into a reduction of the 238Pu needed per mission. The idea was proposed to NASA in 2012 for the yearly NASA NSPIRE competition, which translated to Idaho National Laboratory at the Center for Space Nuclear Research (CSNR) in 2013 for studies of feasibility. However the essentials are unmodified. RTG have been proposed for use on realistic interstellar precursor missions and interstellar probes.An example of this is the Innovative Interstellar Explorer (2003–current) proposal from NASA.An RTG using 241Am was proposed for this type of mission in 2002.This could support mission extensions up to 1000 years on the interstellar probe, because 241Am decays more slowly than 238Pu.Other isotopes for RTG were also examined in the study, looking at traits such as watt/gram, half-life, and decay products.
Cl−CH2CH2−OH + KOH → (CH2CH2)O + KCl + H2O Wurtz measured the boiling point of ethylene oxide as 13.5 °C (56.3 °F), slightly higher than the present value, and discovered the ability of ethylene oxide to react with acids and salts of metals. Wurtz mistakenly assumed that ethylene oxide has the properties of an organic base. This misconception persisted until 1896, when Georg Bredig found that ethylene oxide is not an electrolyte. That it differed from other ethers — particularly by its propensity to engage in the addition reactions typical of unsaturated compounds — had long been a matter of debate. The heterocyclic triangular structure of ethylene oxide was proposed by 1868 or earlier. Wurtz's 1859 synthesis long remained the only method of preparing ethylene oxide, despite numerous attempts, including by Wurtz himself, to produce ethylene oxide directly from ethylene. Only in 1931 did French chemist Theodore Lefort develop a method of direct oxidation of ethylene in the presence of silver catalyst. Since 1940, almost all industrial production of ethylene oxide has relied on this process. Sterilization by ethylene oxide for the preservation of spices was patented in 1938 by the American chemist Lloyd Hall. Ethylene oxide achieved industrial importance during World War I as a precursor to both the coolant ethylene glycol and the chemical weapon mustard gas.
Dautch also teaches Jewish Culture and Holocaust Studies at the University of Roehampton and lectures at the London School of Jewish Studies and JW3. Lionel Davidson (Hull 1922–2009) thriller novelist, Golden Dagger winner, famous for "The night of Wenceslas", "Chelsea murders", "Kolinsky Heights". Lived briefly in Jaffa, Israel at the invitation of the government. Isaac Deutscher (Polish: Izaak Deutscher; 3 April 1907 – 19 August 1967); Polish Jewish Marxist author, journalist and political activist who moved to the United Kingdom before the outbreak of World War II; best known as a biographer of Leon Trotsky and as a commentator on Marxist dialectic and Soviet affairs. His three-volume biography of Trotsky was highly influential among the British New Left in the 1960s and 1970s. Michael Dickson (educator) (born 11 October 1977) dual citizen British-Israeli; author of ISRESILIENCE: What Israelis Can Teach the World; journalist for The Jerusalem Post, Times of Israel, Jewish Chronicle; executive director of StandWithUs Israel in Jerusalem; senior Fellow at Center for International Communication (CIC) of Bar Ilan University; Honorary member of Alpha Epsilon Pi; winner of the Bonei Zion Prize. Jenny Diski (8 July 1947 – 28 April 2016) was a countercultural protagonist, author and contributor to the UK Underground press, colleague of R.D. Laing, notable for starting the Freightliners free school.
Sources: en.wikipedia.org
North Korean citizens returning from other countries were subjected to a 40-day isolation period, plus a subsequent 30-day "medical observation" period. According to North Korean media, nearly 7,000 North Koreans had been subjected to these rules as of 1 March. On 14 March, North Korean state media reported that there were still no confirmed cases in its territory. Kim Jong Un ordered the construction of new hospitals in the country on 18 March. North Korean state media also reported the prior day that groundbreaking on the new Pyongyang General Hospital was underway. Kim told a newspaper linked to the ruling Workers' Party of Korea that the construction of new hospitals was being done for general improvement of the nation's healthcare system, without mentioning COVID-19. On 20 March, North Korean media reported that excepting three foreigners, more than 2,590 people had been released from quarantine in North Pyongan and South Pyongan provinces. Outside organizations provided aid to fight the virus: the Russian government provided test kits; the WHO announced plans to send supplies despite the lack of confirmed cases; and the International Federation of Red Cross and Red Crescent Societies, U.S. State Department, and South Korean government all indicated willingness to help. The U.S. government worked with the United Nations to make exceptions to sanctions, though the organizations were also criticized for slowing down the process for providing aid.
=== Theories of origin === The most commonly held of the three theories of tofu's origin maintains that tofu was discovered by Liu An (179–122 BC), a Han dynasty prince. While plausible, the paucity of reliable sources for this period makes this difficult to conclusively determine. In Chinese history, important inventions were frequently attributed to important leaders and figures of the time. It was used as a cheaper option to meat. In 1960, a stone mural unearthed from an Eastern Han dynasty tomb provided support for the theory of the Han origin of tofu; however some scholars maintain that tofu during the Han dynasty was rudimentary and lacked the firmness and taste for it to be considered as tofu. Another theory suggests that the production method for tofu was discovered accidentally when a slurry of boiled, ground soybeans was mixed with impure sea salt. Such sea salt would probably have contained calcium and magnesium salts, allowing the soy mixture to curdle and produce a tofu-like gel. The last group of theories maintains that the ancient Chinese learned the method for curdling soy milk by emulating the milk curdling techniques of the Mongolians. The primary evidence for this theory is the etymological similarity between the Chinese term rǔfǔ (乳腐), which literally means "milk curd", used during Sui dynasty (AD 581–618), for dishes with a consistency like yogurt or soft cheese, later influenced by Mongolian milk products and methods of production, and the term dòufu (豆腐, "bean curd") or tofu.
In three terms over the next six years, Mizell gained a reputation as a conservative. He opposed the Blue Ridge Power Project, introducing a House Bill in 1974 to add the New River to the National Wild and Scenic Rivers System. Though the bill was unsuccessful at the time, it became law in 1976. Mizell, however, lost his seat to Stephen L. Neal in 1974, also losing to the Democrat when he ran against him in 1976. Presidents Gerald Ford, Ronald Reagan, and George H. W. Bush each appointed him to Assistant Secretary positions within their administrations. After suffering a heart attack in 1998, Mizell died in 1999.
Corruption index (-0.54) Control of corruption (0.47) Bureaucratic quality (0.40) PPP-adjusted GDP per capita (although there is evidence of publication bias) (0.39) Economic freedom (0.35) Human rights violations (-0.33) Political and ethnic violence (-0.28) Civil liberties (0.28) Life expectancy at birth (0.27) Satisfaction with standard of living (0.24)
== Mass spectrometry == Mass spectrometry has been successfully used to identify changes in the composition of the adhesome upon perturbation. Schiller et al. as well as Kuo et al. examined the effect of inhibition of myosin contractility on the integrin adhesome composition and found LIM domain proteins and beta-PIX to be tension sensitive. Gou et al. found little change in the cadherin adhesome after calcium depletion from the media, which essentially abrogates cell-cell adhesion. Reinhard Fassler and co-workers used proteomics on specifically engineered cell lines to distinguish between the adhesome of β1- and αv-class integrins.
Sources: en.wikipedia.org
GHK denotes the unbound chain of three amino acids. GHK-Cu describes the form in which a copper(II) ion is held by that chain. The two are not interchangeable in solution, since charge, molecular weight, and reactivity differ.
The chain occurs in human plasma, saliva, and urine. Measured amounts are reported to fall with age. Copper binding by the sequence is treated as part of normal metal handling in tissue.
The bound copper(II) centre contributes to redox behaviour and to stability under physiological conditions. Free copper ions can participate in reactions that generate reactive species, while chelated metal is generally more controlled. The chain may also serve as a carrier for copper in experimental systems.
It is the copper(II) complex of the tripeptide glycyl-L-histidyl-lysine, a sequence of three amino acids. The copper ion is held by the histidine imidazole, the terminal amino group, and an amide nitrogen. The bound form is distinct from the free peptide in charge, color, and stability.