If you have been reading about Copper tripeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-11-08. Numbers and descriptions here follow the published literature rather than marketing material.
Material described in research and cosmetic supply chains is typically a synthetic peptide supplied as a lyophilized powder. Purity is commonly reported through chromatographic separation, often at 95 percent or higher, while copper content is confirmed by separate elemental analysis. Batch variation in color and solubility can reflect residual counter-ions, moisture, or partial oxidation of the peptide. Because the complex is not a single regulatory entity, specifications differ between suppliers and are not standardized internationally.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide binds copper through its histidine imidazole nitrogen, its terminal amino group, and a deprotonated amide nitrogen, creating a stable chelate ring. The resulting complex carries a distinctive blue to blue-violet color, which arises from copper d-d electronic transitions. In the solid state it is usually handled as a powder, while in solution the complex can dissociate and re-form depending on pH and competing ligands. The name copper tripeptide-1 is widely used in ingredient listings.
The tripeptide was first isolated from a human plasma filtrate in 1973 during studies of tissue repair factors. Later work detected the free peptide and its copper complex in saliva, urine, and wound fluid, suggesting a natural role in tissue remodeling. Plasma concentrations reported in early literature decline with age, a pattern often cited in discussions of skin aging. Whether these endogenous levels are directly functional or largely incidental remains an open question. The peptide sequence is conserved across mammalian species.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H24N6O4 | Free tripeptide, without copper |
| Molecular weight | About 340 g/mol | Peptide portion only |
| Appearance | Blue to violet powder | Color from copper coordination |
| Solubility | Soluble in water | pH influences dissolution |
| Common synonyms | Copper tripeptide-1, Cu-GHK | Seen on ingredient labels |
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.
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.
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.
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.
==== Acquisitions and mergers ==== In June 2000, Pfizer acquired Warner-Lambert outright for $116 billion. To satisfy conditions imposed by antitrust regulators at the Federal Trade Commission, Pfizer sold off or transferred stakes in several minor products, including RID (a shampoo for treatment of head lice, sold to Bayer) and Warner-Lambert's antidepressant Celexa (which competes with Zoloft). The acquisition created what was, at the time, the second-largest pharmaceutical company worldwide. In 2003, Pfizer merged with Pharmacia, and in the process acquired Searle and SUGEN. Searle had developed Flagyl (metronidazole), a nitroimidazole antibiotic medication used particularly for anaerobic bacteria and protozoa. Searle also developed celecoxib (Celebrex) a COX-2 inhibitor and nonsteroidal anti-inflammatory drug (NSAID) used to treat the pain and inflammation in osteoarthritis, acute pain in adults, rheumatoid arthritis, ankylosing spondylitis, painful menstruation, and juvenile rheumatoid arthritis. SUGEN, a company focused on protein kinase inhibitors, had pioneered the use of ATP-mimetic small molecules to block signal transduction. The SUGEN facility was shut down in 2003 by Pfizer, with the loss of more than 300 jobs, and several programs were transferred to Pfizer. These included sunitinib (Sutent), a cancer medication which was approved for human use by the FDA in January 2006. A related compound, SU11654 (Toceranib), was also approved for cancer in dogs, and the ALK inhibitor Crizotinib also grew out of a SUGEN program.
== Mode of action == When used as a food additive, ractopamine added to feed can be distributed by the blood to the muscle tissues, where it serves as a full agonist to murine (mouse or rat) TAAR1, a receptor protein (not necessarily in humans). It is also an agonist to beta-adrenergic receptors and a dopamine releasing agent. A cascade of events will then be initiated to increase protein synthesis, which results in increased muscle fiber size. Ractopamine is known to increase the rate of weight gain, improve feed efficiency, and increase carcass leanness in finishing swine. Its use in finishing swine yields about 3 kg (6.6 lb) of additional lean pork per animal, and improves feed efficiency by 10%. In cattle on 28 January 2004 Elanco Animal Health made Optaflexx commercially available in the US. Optaflexx is a "medicated feed additive that is labeled only for use in steers or market heifers (not breeding heifers or bulls) during the last 28–42 days on feed."
The Ukrainian Defence Ministry said that its forces had retaken about 20sq km (7.5sq miles) of territory from Russian forces in the north and south of the outskirts of Bakhmut in recent days while acknowledging continued Russian advances inside the city. The Wagner Group's head Yevgeny Prigozhin claimed that an American citizen was killed fighting in Bakhmut, in a video posted on Telegram that showed him inspecting a body and what he claimed to be US identification documents. In Kharkiv Oblast, two people where killed in another bout of Russian shelling in Dvorichna. South African President Cyril Ramaphosa said both Presidents Putin and Zelenskyy had agreed to receive an African mission that would propose a peace plan. He said the plan was backed by the presidents of Senegal, Uganda and Egypt and that UN Secretary-General António Guterres, the United States and the United Kingdom had also been briefed. The commander of the land forces of the South African National Defence Force, Lieutenant-General Lawrence Mbatha, visited Moscow. A Moscow court sentenced Colombian resident and Russian passport-holder Alberto Enrique Giraldo Saray to five years and two months in prison for spreading "fake news" about the actions of the Russian military in Ukraine. The US State Department condemned the arrest of a local embassy employee in Russia for alleged spying.
In 1994, world production of H2O2 was around 1.9 million tonnes and grew to 2.2 million in 2006, most of which was at a concentration of 70% or less. In that year, bulk 30% H2O2 sold for around 0.54 USD/kg, equivalent to US$1.50/kg (US$0.68/lb) on a 100% purity basis. Hydrogen peroxide is manufactured almost exclusively by the anthraquinone process, which was originally developed by BASF in 1939. It begins with the reduction of an anthraquinone (such as 2-ethylanthraquinone or the 2-amyl derivative) to the corresponding anthrahydroquinone, typically by hydrogenation on a palladium catalyst. In the presence of oxygen, the anthrahydroquinone then undergoes autoxidation: the labile hydrogen atoms of the hydroxy groups transfer to the oxygen molecule, to give hydrogen peroxide and regenerating the anthraquinone. Most commercial processes achieve oxidation by passing compressed air through a solution of the anthrahydroquinone, with the hydrogen peroxide then extracted from the solution and the anthraquinone recycled back for successive cycles of hydrogenation and oxidation. The net reaction for the anthraquinone-catalyzed process is:
== Ecology == In southern Rajasthan, many of the hills are well-clad with vegetation, and there, Euphorbia caducifolia is associated with Butea monosperma, Millettia pinnata, Syzygium hyrianium, Wrightia tinctoria and Ziziphus nummularia. In the arid region near Sambhar Salt Lake, it is associated with thorny scrub such as Anogeissus pendula and Boswellia.
Sources: en.wikipedia.org
=== January === 1 January – A visit by Thor the Walrus to Scarborough harbour, North Yorkshire overnight on New Year's Eve results in the town's New Year fireworks celebrations being cancelled to let the walrus rest for his journey to the Arctic. He was previously spotted at Pagham Harbour, Calshot, Hampshire in December 2022. 2 January Three people are killed by a fire at the New County Hotel in Perth, Scotland. Thor the Walrus makes an appearance in Blyth, Northumberland. 3 January – 40,000 railway workers who are members of the RMT union hold the first of two 48-hour strikes this week, severely disrupting train services in England, Scotland, and Wales. 5 January The government confirms it will not go ahead with a plan to privatise Channel 4. The Met Office confirms that 2022 was the UK's warmest year since records began in 1884, with an average annual temperature above 10 °C (50 °F) for the first time. BioNTech announces a strategic partnership with the UK government to provide up to 10,000 patients with personalised mRNA cancer immunotherapies by 2030. 6 January – COVID-19 in the UK: Almost three million people were infected with COVID-19 over the Christmas period (the highest since July 2022), the latest Office for National Statistics data suggests, with one in 20 having the virus in England, one in 18 in Wales, one in 25 in Scotland and one in 16 in Northern Ireland. XBB.1.5, the new Omicron variant of the virus, is believed to be responsible for one in 200 infections in the UK.
=== Liquid chromatography === Similar to gas chromatography, liquid chromatography is used to separate molecules before detection; however, LC has a liquid mobile phase. After growing modern microbes that synthesize tetrahymanol, many of the biomolecules are too polar to separate on GC, so LC is used to characterize the abundance of different lipids. There are two main types of LC: normal and reversed phase. In the former, the stationary phase is polar and the mobile phase becomes increasingly non-polar as the separation proceeds. Reversed phase chromatography is the inverse of this set up, non-polar stationary phase with polar mobile phase.
== Measured variables and units == In principle, reducing the exposure of the human organism to ionizing radiation to zero is not possible and perhaps not even sensible. The human organism has been accustomed to natural radioactivity for thousands of years and ultimately this also triggers mutations (changes in genetic material), which are the cause of the development of life on earth. The mutation-inducing effect of high-energy radiation was first demonstrated in 1927 by Hermann Joseph Muller (1890-1967). Three years after its establishment in 1958, the United Nations Scientific Committee on the Effects of Atomic Radiation adopted the Linear No-Threshold (LNT) model - a linear dose-effect relationship without a threshold - largely at the instigation of the Soviet Union. The dose-response relationship measured at high doses was extrapolated linearly to low doses. There would be no threshold, since even the smallest amounts of ionizing radiation would trigger some biological effect. The LNT model ignores not only possible radiation hormesis, but also the known ability of cells to repair genetic damage and the ability of the organism to remove damaged cells. Between 1963 and 1969, John W. Gofman (1918-2007) and Arthur R. Tamplin of the University of California, Berkeley, conducted research for the United States Atomic Energy Commission (USAEC, 1946-1974) investigating the relationship between radiation doses and cancer incidence. Their findings sparked a fierce controversy in the United States beginning in 1969. Starting in 1970, Ernest J.
Intracellular bacterial pathogens invade eukaryotic cells (which may lead to the formation of phagolysosomes and/or autophagy activation), or bacteria may be engulfed by phagocytes (macrophages, monocytes, neutrophils...). The bacteria-containing phagosome may then fuse with endosomes and lysosomes, leading to degradation of bacteria and generation of polymeric peptidoglycan fragments and muropeptides.
=== Pharmacokinetics === Salvinorin A is effectively deactivated by the gastrointestinal system, so alternative routes of administration must be used for better absorption. It is absorbed by oral mucosa. It has a half-life of around 8 minutes in non-human primates.
Sources: en.wikipedia.org
== Metabolism == The enzyme taxifolin 8-monooxygenase uses taxifolin, NADH, NADPH, H+, and O2 to produce 2,3-dihydrogossypetin, NAD+, NADP+, and H2O. The enzyme leucocyanidin oxygenase uses leucocyanidin, alpha-ketoglutarate, and O2 to produce cis-dihydroquercetin, taxifolin, succinate, CO2, and H2O.
is dimensionless since activity is dimensionless. Activities of the products of dissociation are placed in the numerator, activities of the reactants are placed in the denominator. See activity coefficient for a derivation of this expression.
=== Extra-articular === JIA is associated with inflammation in the front of the eye (acute or chronic anterior uveitis), which affects about one in six children with JIA. Eye involvement occurs most commonly in girls, those with only a few joints involved (oligoarthritis), those with rheumatoid factor negative polyarticular JIA, and those with a positive anti-nuclear antibody (ANA). Girls younger than six years old are at greatest risk of anterior uveitis. 90% of chronic anterior uveitis occurs within 4 years of JIA diagnosis. Acute anterior uveitis is seen in 11-13% of JIA and is more commonly associated with the enthesitis related arthritis subtype. It presents with light sensitivity, redness of the eyes and eye pain. Regular eye exams are required for children affected by acute or chronic anterior uveitis related to JIA. Children with the Systemic JIA subtype often experience extra-articular manifestations including fever, rash, enlarged lymph nodes, enlarged liver or spleen, serositis and anemia.
=== Oxoacids, oxoanions, and oxoacid salts === Many nitrogen oxoacids are known, though most of them are unstable as pure compounds and are known only as aqueous solutions or as salts. Hyponitrous acid (H2N2O2) is a weak diprotic acid with the structure HON=NOH (pKa1 6.9, pKa2 11.6). Acidic solutions are quite stable but above pH 4 base-catalysed decomposition occurs via [HONNO]− to nitrous oxide and the hydroxide anion. Hyponitrites (involving the N2O2−2 anion) are stable to reducing agents and more commonly act as reducing agents themselves. They are an intermediate step in the oxidation of ammonia to nitrite, which occurs in the nitrogen cycle. Hyponitrite can act as a bridging or chelating bidentate ligand. Nitrous acid (HNO2) is not known as a pure compound, but is a common component in gaseous equilibria and is an important aqueous reagent: its aqueous solutions may be made from acidifying cool aqueous nitrite (NO−2, bent) solutions, although already at room temperature disproportionation to nitrate and nitric oxide is significant. It is a weak acid with pKa 3.35 at 18 °C. They may be titrimetrically analysed by their oxidation to nitrate by permanganate. They are readily reduced to nitrous oxide and nitric oxide by sulfur dioxide, to hyponitrous acid with tin(II), and to ammonia with hydrogen sulfide. Salts of hydrazinium N2H+5 react with nitrous acid to produce azides which further react to give nitrous oxide and nitrogen.
==== Urquía Carreño resigns ==== On August 18, 2024, a special session of more than a hundred Freemasons was called by Urquía Carreño to gather at the theatre hall of the Grand Lodge of Cuba, on the 3rd floor of the building. One Cuban Freemason told reporters that: "...he had manipulated a circus to stay in office. He's shameless, they were lies after lies; all the brothers were standing asking him to hand over the keys to his office." The people in the theatre started chanting: "Hand over and leave!" After tensions had escalated, Urquía Carreño left the theatre to go back to his office. However, the Freemasons followed him up to the eleventh floor. Urquía Carreño agreed to meet with representatives of the delegation in his office, so three men were chosen to represent them. The three men sat with three of Urquía Carreño's men, and discussed terms of negotiation, while the rest of the delegation waited in the hallway. On August 18, 2024, after two hours of negotiation, Urquía Carreño finally relented and agreed to tender his resignation. In his resignation, he said that it was: "for the good of the institution." Mayker Filema Duarte assumed the role of Acting Grand Master until an election could be held, and immediately launched a financial audit of the entire Grand Lodge. At the beginning of September, Filema Duarte accused Urquía Carreño of the theft of yet another $MN2,116,555.33, stolen sometime between January and August 2024.
Sources: en.wikipedia.org
It is a complex of the tripeptide glycyl-L-histidyl-L-lysine with a copper(II) ion. The peptide coordinates the metal through its histidine, amino terminus, and an amide nitrogen. It is often listed simply as copper tripeptide-1.
The peptide and its copper form have been detected in human plasma, saliva, and urine. Early reports describe levels that fall with age. The functional meaning of these pools is still debated.
Chromatographic separation gives peptide purity, often reported as a percentage. Copper content is checked by a separate elemental method. Moisture and counter-ions may be reported as well.
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.