This is a working overview of glycyl-histidyl-lysine, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-30 and is reviewed periodically as new material appears.
Published work on GHK-Cu concentrates largely on cell culture systems rather than whole organisms. Frequently used endpoints include collagen synthesis, expression of matrix metalloproteinases, and migration of fibroblasts. Some reports describe antioxidant behavior, while others stress delivery of copper into cells. These mechanisms are proposed rather than demonstrated, and the relative weight of each pathway is unclear. Human trials are few and generally small, so laboratory findings should not be read as confirmed clinical results.
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 carries three residues in the order glycine, histidine, lysine, which places a small, flexible chain around a single metal centre. Compared with larger copper-binding proteins, the complex is compact and its coordination chemistry can be reproduced with synthetic peptide in a laboratory. Published structural work agrees on the nitrogen donor set but differs in the exact geometry assigned under some conditions, so the arrangement is best treated as well characterised in outline rather than fixed in every detail.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide was isolated from human plasma in the early 1970s by Loren Pickart, who observed that a plasma fraction from young donors stimulated growth in cultured liver cells. The copper-bound form is abbreviated GHK-Cu, while the metal-free peptide is written simply as GHK. In the research literature the complex also appears as copper tripeptide-1 and as glycyl-histidyl-lysine copper complex.
Copper(II) binds the peptide through four nitrogen donors: the terminal amino group, the imidazole nitrogen of histidine, and two deprotonated amide nitrogens of the peptide backbone. This tetradentate arrangement gives a roughly square-planar geometry, the thermodynamically favoured form near neutral pH. Because the amide nitrogens must lose a proton before they can coordinate, complex formation is strongly pH-dependent, and the fully coordinated species dominates only above mildly acidic conditions. Electronic transitions within the copper d orbital set produce the characteristic blue to violet colour in aqueous solution.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II) peptide complex | Peptide chain coordinated to a single metal ion |
| CAS number | 89030-95-5 | Indexed for the peptide-copper complex |
| Molecular formula | C14H22CuN6O4 | Approximate formula for a one-to-one complex |
| Appearance | Blue to violet solid | Color from copper d-d transitions |
| Solubility class | Freely soluble in water | Also dispersible in some polar solvents |
Proposed mechanisms for copper peptide activity center on delivery of copper ions to cells and on peptide fragments acting as signaling molecules. Copper is a cofactor for enzymes involved in collagen cross-linking and antioxidant defense, and the peptide may improve its availability at target sites. Separately, the tripeptide and its breakdown products have been reported to influence gene expression in cultured fibroblasts. Much of this evidence comes from laboratory cell cultures and animal models rather than controlled human trials. The relative contribution of the copper ion and the peptide sequence is therefore not fully settled.
Stability depends on temperature, light exposure, moisture, and the presence of oxidizing or reducing agents. Solid material held dry and protected from light is generally more stable than aqueous solutions, which can undergo gradual degradation. Recommended storage in much of the literature is a freezer at around minus twenty degrees Celsius for long-term retention, with working aliquots kept cold and shielded from light. Repeated freeze-thaw cycles and alkaline pH are commonly noted as factors that accelerate loss of the intact complex, though exact degradation rates vary.
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.
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.
GHK-Cu is a coordination complex formed from the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide binds copper through its histidine imidazole nitrogen, the terminal amino group, and the deprotonated amide nitrogen. This arrangement creates a square-planar or distorted geometry around the metal center, depending on pH and the presence of competing ligands. The complex occurs naturally in human plasma, saliva, and urine at low concentrations, and its sequence is conserved across many vertebrate species.
Discovery of GHK is generally attributed to work in the 1970s that isolated a plasma factor influencing liver cell behavior. Subsequent studies identified the copper-binding tripeptide and its ability to chelate copper with high affinity. Early reports linked the complex to wound healing and tissue remodeling in animal models. The free peptide and the copper-bound form have different properties, so the two are distinguished in the literature. Whether endogenous GHK-Cu serves a single primary physiological role remains an open question.
The molecular weight and charge of GHK-Cu depend on the pH and the number of coordinated ligands. At neutral pH, the peptide typically binds one copper ion, but ternary complexes with other biomolecules can form. Spectroscopic methods such as electron paramagnetic resonance and circular dichroism are used to study the coordination environment. Reports on the exact geometry vary because the complex is dynamic in solution. Researchers often use synthetic GHK-Cu rather than extracted material to control stoichiometry and purity.
== Repackaging process and stability data == The transient or definitive displacement of the solid oral form from the original atmosphere to enter a repackaging process, sometimes automated, is likely to play a primary role in the pharmaceutical controversy in some countries. However, the solid oral dose is to be repackaged in materials with defined quality. Considering these data, a review of the literature for determination of conditions for repackaged drug stability according to different international guidelines is presented by F Lagrange.
Obsidian hydration dating (OHD) is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping, or breaking off pieces in a controlled manner, such as pressure flaking. Obsidian obeys the property of mineral hydration and absorbs water, when exposed to air at a well-defined rate. When an unworked nodule of obsidian is initially fractured, there is typically less than 1% water present. Over time, water slowly diffuses into the artifact forming a narrow "band", "rim", or "rind" that can be seen and measured with many different techniques such as a high-power microscope with 40–80 power magnification, depth profiling with SIMS (secondary ion mass spectrometry), and IR-PAS (infra red photoacoustic spectroscopy). In order to use obsidian hydration for absolute dating, the conditions that the sample has been exposed to and its origin must be understood or compared to samples of a known age (e.g. as a result of radiocarbon dating of associated materials).
On 1 September 1983, the Soviet Union shot down Korean Air Lines Flight 007, a Boeing 747 with 269 people aboard, including sitting Congressman Larry McDonald, an action which Reagan characterized as a massacre. The airliner was en route from Anchorage to Seoul but owing to a navigational mistake made by the crew, it flew through Russian prohibited airspace. The Soviet Air Force treated the unidentified aircraft as an intruding U.S. spy plane and destroyed it with air-to-air missiles. The incident increased support for military deployment, overseen by Reagan, which stood in place until the later accords between Reagan and Mikhail Gorbachev. During the early hours of 26 September 1983, the 1983 Soviet nuclear false alarm incident occurred; systems in Serpukhov-15 underwent a glitch that claimed several intercontinental ballistic missiles were heading towards Russia, but officer Stanislav Petrov correctly suspected it was a false alarm, ensuring the Soviets did not respond to the non-existent attack. As such, he has been credited as "the man who saved the world". The Able Archer 83 exercise in November 1983, a realistic simulation of a coordinated NATO nuclear release, was perhaps the most dangerous moment since the Cuban Missile Crisis, as the Soviet leadership feared that a nuclear attack might be imminent. American domestic public concerns about intervening in foreign conflicts persisted from the end of the Vietnam War. The Reagan administration emphasized the use of quick, low-cost counterinsurgency tactics to intervene in foreign conflicts.
=== September === September 8, 2008: Latvia Latvia joins its northern neighbor Estonia in recession as GDP falls 0.2% in the second quarter from the first quarter, when it fell 0.3%. Property markets and construction have suffered in both Baltic states.
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Examination of remains of Homo erectus from Kenya, which are about 1.6 million years old, has revealed signs typical of yaws. The genetic analysis of the yaws causative bacteria—Treponema pallidum pertenue—has led to the conclusion that yaws is the most ancient of the four known Treponema diseases. All other Treponema pallidum subspecies probably evolved from Treponema pallidum pertenue. Yaws is believed to have originated in tropical areas of Africa and spread to other tropical areas of the world via immigration and the slave trade. The latter is likely the way it was introduced to Europe from Africa in the 15th century. The first unambiguous description of yaws was made by the Dutch physician Willem Piso. Yaws was clearly described in 1679 among African slaves by Thomas Sydenham in his epistle on venereal diseases, although he thought that it was the same disease as syphilis. The causative agent of yaws was discovered in 1905 by Aldo Castellani in ulcers of patients from Ceylon. The current English name is believed to be of Carib origin, from "yaya", meaning sore. Towards the end of the Second World War, yaws became widespread in the North of Malaya under Japanese occupation. After the country was liberated, the population was treated for yaws by injections of salvarsan, of which there was a great shortage, so only those with stage 1 were treated.
==== Industrial applications ==== Many industrial processes rely on reactions using chemicals dissolved in water, suspension of solids in water slurries or using water to dissolve and extract substances, or to wash products or process equipment. Processes such as mining, chemical pulping, pulp bleaching, paper manufacturing, textile production, dyeing, printing, and cooling of power plants use large amounts of water, requiring a dedicated water source, and often cause significant water pollution. Water is used in power generation. Hydroelectricity is electricity obtained from hydropower. Hydroelectric power comes from water driving a water turbine connected to a generator. Hydroelectricity is a low-cost, non-polluting, renewable energy source. The energy is supplied by the motion of water. Typically a dam is constructed on a river, creating an artificial lake behind it. Water flowing out of the lake is forced through turbines that turn generators.
=== Diseases === Polycystic ovary syndrome and non-alcoholic fatty liver disease (NAFLD) are associated with insulin resistance. Hepatitis C also makes people three to four times more likely to develop type 2 diabetes and insulin resistance.
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Most chloroplasts in a photosynthetic cell do not develop directly from proplastids or etioplasts. In fact, a typical shoot meristematic plant cell contains only 7–20 proplastids. These proplastids differentiate into chloroplasts, which divide to create the 30–70 chloroplasts found in a mature photosynthetic plant cell. If the cell divides, chloroplast division provides the additional chloroplasts to partition between the two daughter cells. In single-celled algae, chloroplast division is the only way new chloroplasts are formed. There is no proplastid differentiation—when an algal cell divides, its chloroplast divides along with it, and each daughter cell receives a mature chloroplast. Almost all chloroplasts in a cell divide, rather than a small group of rapidly dividing chloroplasts. Chloroplasts have no definite S-phase—their DNA replication is not synchronized or limited to that of their host cells. Much of what we know about chloroplast division comes from studying organisms like Arabidopsis and the red alga Cyanidioschyzon merolæ.
CO(NH2)2 → [NH4]+[OCN]− → HNCO + NH3 This decomposition is at its worst when the urea solution is heated at low pressure, which happens when the solution is concentrated for prilling or granulation (see below). The reaction products mostly volatilize into the overhead vapours, and recombine when these condense to form urea again, which contaminates the process condensate.
Serotonin 5-HT2A receptor antagonists can block the hallucinogenic effects of serotonergic psychedelics like psilocybin in humans. Numerous drugs act as serotonin 5-HT2A receptor antagonists, including antidepressants like trazodone and mirtazapine, antipsychotics like quetiapine, olanzapine, and risperidone, and other agents like ketanserin, pimavanserin, cyproheptadine, and pizotifen. Such drugs are sometimes called "trip killers" because they can prevent or abort psychedelics' hallucinogenic effects. Serotonin 5-HT2A receptor antagonists that have been specifically shown in clinical studies to diminish or abolish psilocybin's effects include ketanserin, risperidone, and chlorpromazine. Serotonin 5-HT2A receptor antagonists like antipsychotics should be stopped five half-lives or at least seven days before a psychedelic session. The serotonin 5-HT1A receptor partial agonist buspirone has been found to markedly reduce psilocybin's hallucinogenic effects in humans. Conversely, the serotonin 5-HT1A receptor antagonist pindolol has been found to robustly potentiate the hallucinogenic effects of the related psychedelic dimethyltryptamine (DMT) in humans. Selective serotonin reuptake inhibitors (SSRIs) may modify psilocybin's effects, for instance moderately diminishing them. One clinical trial found that psilocybin's hallucinogenic and "good drug" effects were not modified by the SSRI escitalopram, but that its "bad drug effects" such as anxiety, as well as ego dissolution, were reduced, among other changes.
== Release == Season 3 was promoted with the tagline "May God have mercy". Many of the episode titles are references to Westerns and the Bible. The premiere screened at Coachella 2026 on April 2, 2026. The season had its red carpet premiere on April 7, 2026. In the United States, the season premiered on April 12, 2026, with its finale was released on May 31. In the United Kingdom and the Republic of Ireland, each episode was released at the same time as its U.S. premiere, through Sky Atlantic's streaming service Now.
Sources: en.wikipedia.org
It is the copper complex of the tripeptide glycyl-L-histidyl-lysine. The metal ion is held by the histidine imidazole group and the peptide N-terminus. Most research on it concerns skin and wound models.
The tripeptide was first isolated from human plasma and has also been reported in saliva and urine. Plasma levels appear to decline with age in some small studies. Those observations rest on limited sample sizes.
It is not authorized as a systemic medicine in most countries. Cosmetic preparations list it as an ingredient rather than an active pharmaceutical substance. Legal status therefore differs by jurisdiction.
It consists of a three-amino-acid peptide, glycine-histidine-lysine, bound to one copper(II) ion. The peptide supplies four nitrogen donor atoms, and the resulting complex is stable in neutral aqueous solution. The metal-free peptide is usually called GHK.