Everything below concerns Copper(II). We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-30. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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 |
|---|---|---|
| Sequence | Gly-His-Lys | Three amino acids; histidine supplies the main copper-binding nitrogen |
| Bound metal | Copper(II) | Coordination is described as square-planar around the metal centre |
| Appearance | Blue to violet solid | Colour originates from copper d-d electronic transitions |
| Solubility class | Freely soluble in water | Aqueous solutions are often slightly acidic |
| Common synonyms | Copper tripeptide, Cu-GHK | Ingredient lists may say only 'copper peptide' without giving the sequence |
The copper-binding activity of this sequence was described in the 1970s during studies of liver tissue and plasma factors. Early work identified the peptide as a component that influenced copper uptake by cells and that appeared in wound fluid. Later investigations examined its presence across species, reporting the same chain in human and animal samples. A decline in measured concentration with age became a recurring observation, although the underlying causes remain incompletely characterised.
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.
Identity and purity are normally checked by reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry. The peptide absorbs in the ultraviolet region, and the copper complex also shows a broad visible absorption band that can be followed spectroscopically. Copper content is measured separately, for example by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy, because the peptide assay alone does not confirm how much metal is bound. Purity figures therefore need a stated basis: peptide peak area, copper content, or both.
Aqueous GHK-Cu solutions are less stable than the dry powder. Light, dissolved oxygen and elevated temperature all accelerate loss of the intact complex, and the main observable changes are fading of the blue colour and the appearance of peptide fragments. Acidic conditions protonate the histidine imidazole and weaken copper binding, while strongly alkaline conditions promote hydrolysis of the peptide backbone. Because several degradation routes operate at once, a single shelf-life figure does not describe all storage conditions.
=== Test for milk freshness === Methylene blue is a dye behaving as a redox indicator that is commonly used in the food industry to test the freshness of milk and dairy products. A few drops of methylene blue solution added to a sample of milk should remain blue (oxidized form in the presence of enough dissolved O2), otherwise (discoloration caused by the reduction of methylene blue into its colorless reduced form) the dissolved O2 concentration in the milk sample is low indicating that the milk is not fresh (already abiotically oxidized by O2 whose concentration in solution decreases) or could be contaminated by bacteria also consuming the atmospheric O2 dissolved in the milk. In other words, aerobic conditions should prevail in fresh milk, and methylene blue is simply used as an indicator of the dissolved oxygen remaining in the milk.
=== Recursive directional ligation (RDL) === In recursive directional ligation, the gene encoding the monomer is inserted into a plasmid with restriction sites that are recognized by at least two endonucleases. The endonucleases will cut the plasmid, releasing the gene of interest. Then, this single gene is inserted into a recipient plasmid vector already containing one copy of the ELP monomer gene via digestion of the recipient plasmid with the same restriction endonucleases used on the donor plasmid and a subsequent ligation step. From this process, a sequence of two ELP monomer genes is retrieved. RDL allows for the controlled synthesis of ELP gene oligomers, in which single gene segments are sequentially added. However, the restriction endonucleases used are limited to those that do not cut within the ELP monomer gene itself, as this would lead to loss of crucial nucleotides and a potential frameshift mutation in the protein.
The marsupial thylacine (Tasmanian tiger or Tasmanian wolf) had many resemblances to placental canids. Several mammal groups have independently evolved prickly protrusions of the skin – echidnas (monotremes), the insectivorous hedgehogs, some tenrecs (a diverse group of shrew-like Malagasy mammals), Old World porcupines (rodents) and New World porcupines (another biological family of rodents). In this case, because the two groups of porcupines are closely related, they would be considered to be examples of parallel evolution; however, neither echidnas, nor hedgehogs, nor tenrecs are close relatives of the Rodentia. In fact, the last common ancestor of all of these groups lived in the age of the dinosaurs. The eutriconodont Spinolestes that lived in the Early Cretaceous Period represents an even earlier example of a spiny mammal, unrelated to any modern mammal group. Catlike sabre-toothed predators evolved in three distinct lineages of mammals – carnivorans like the sabre-toothed cats, and nimravids ("false" sabre-tooths), the sparassodont family Thylacosmilidae ("marsupial" sabre-tooths), the gorgonopsids and the creodonts also developed long canine teeth, but with no other particular physical similarities. A number of mammals have developed powerful fore claws and long, sticky tongues that allow them to open the homes of social insects (e.g., ants and termites) and consume them (myrmecophagy).
== Preparation == Field corn grain is dried and then treated by cooking the mature, hard grain in a diluted solution of slaked lime (calcium hydroxide) or wood ash and then letting it soak for many hours. The soaked maize is then rinsed thoroughly to remove the unpalatable flavor of the alkali. This process is nixtamalization, and it produces hominy, which is ground into a relatively dry dough to create fresh masa. The fresh masa can be sold or used directly, or can be dehydrated and blended into a powder to create masa harina, or masa flour. Lime and ash are highly alkaline, which helps the dissolution of hemicellulose, the major glue-like component of the maize cell walls, and loosens the hulls from the kernels and softens the corn. Some of the corn oil is broken down into emulsifying agents (monoglycerides and diglycerides), while bonding of the corn proteins to each other is also facilitated. The divalent calcium in lime acts as a cross-linking agent for protein and polysaccharide acidic side chains. The chemical changes in masa allow dough formation, and also allow the nutrient niacin to be absorbed by the digestive tract. By contrast, untreated cornmeal is unable to form dough on the addition of water, and a diet heavily reliant on its consumption is a risk factor for pellagra.
These pathways are also important in environmental science, with the xenobiotic metabolism of microorganisms determining whether a pollutant will be broken down during bioremediation, or persist in the environment. The enzymes of xenobiotic metabolism, particularly the glutathione S-transferases are also important in agriculture, since they may produce resistance to pesticides and herbicides.
Sources: en.wikipedia.org
Drug discovery is the initial phase of research focused on identifying and validating new chemical compounds (lead compounds) that are intended to treat a disease. Drug design is an inventive method used within the discovery phase and encompasses the designing of molecules that are complementary in polarity (charge) and shape (stereochemistry) to a given biomolecular target. After a lead compound has been identified through drug discovery, drug development involves bringing the drug to the market. Drug discovery is related to pharmacoeconomics, which is the sub-discipline of health economics that considers the value of drugs. Pharmacoeconomics evaluates the cost and benefits of drugs in order to guide optimal healthcare resource allocation. The techniques used for the formulation and manufacturing of drugs are studied by pharmaceutical engineering, a branch of engineering. Safety pharmacology specializes in detecting and investigating potential undesirable and adverse effects of drugs.
== History == FT-ICR was invented by Melvin B. Comisarow and Alan G. Marshall at the University of British Columbia. The first paper appeared in Chemical Physics Letters in 1974. The inspiration was earlier developments in conventional ICR and Fourier-transform nuclear magnetic resonance (FT-NMR) spectrometry. Marshall has continued to develop the technique at The Ohio State University and Florida State University.
With a chemical structure resembling amphetamines and other precursors, myristicin can also be used to synthesize psychoactive amphetamines. Under controlled conditions, myristicin isolated from nutmeg oil can be converted into MMDMA, a synthetic "designer drug" that is less potent than MDMA but produces comparable stimulant and hallucinogenic effects.
P.H., professor in the Department of Biostatistics in the UAB School of Public Health George Howard explains that "Asking someone how much they weigh is probably the second worst question behind how much money they make," "From past research, we know that women tend to under-report their weight, and men tend to over-report their height." Howard said as far as equivalency between the self-reported and measured data sets, the East South Central region showed the least misreporting. "This suggests that people from the South come closer to telling the truth than people from other regions, perhaps because there's not the social stigma of being obese in the South as there is in other regions." The area of the United States with the highest obesity rate is American Samoa (75% obese and 95% overweight).
Sources: en.wikipedia.org
=== The Ait Soussan organisation === The Ait Soussan organisation is a criminal organisation led by Houssine Ait Soussan. He is a major drug trafficker who also used to own the Dutch football-club ZVV 't Knooppunt. Houssine Ait Soussan is notably a prominent figure within the Moroccan mafia in the Netherlands and Belgium, and he was also allied with the Bouyakhrichan organisation. The Ait Soussan organisation is responsible for distributing tons of cocaine across all of Western Europe. Houssine Ait Soussan is also considered to be one of the original participating figures within the Mocro-War, which was sparked after a missing shipment of cocaine in the port of Antwerp. As a result of this, Houssine Ait Soussan is believed to be behind the kidnapping of Abdelkader "the Jew" Bouker, a major Belgian-Moroccan drug trafficker who worked closely together with the Israeli mafia, and went missing in 2016. He was also believed to be behind the kidnapping of Younes El Ballouti, the younger brother of Othman El Ballouti, who is considered to be one of the biggest drug lords in Belgium. Houssine Ait Soussan allegedly kidnapped him as revenge, because Colombian cartels preferred to work with the El Ballouti clan instead of his organisation. Houssine Ait Soussan was for many years wanted by the Dutch and Belgian authorities for his involvement in numerous of assassinations and kidnappings, which mostly took place in Antwerp and Brussels. He orchestrated his kidnappings and assassinations from Central America, to stay off the radar from the European police.
== Honours and awards == 2000 – Human Frontier Science Program Long-Term Postdoctoral Fellowship. 2004 – Career Development Award, Human Frontier Science Program 2007 – Starting Grant, European Research Council 2013 – Rector's Prize for Excellence in Research and Teaching, Hebrew University of Jerusalem 2015 – Sir Zelman Cowen Universities Fund Prize for Discovery in Medical Research 2018 – Michael Milken Prize for Excellence in Teaching.
==== Ethiopia ==== Approximately 30% of the Ethiopian population carry an extra copy of the gene CYP2D6, and are classified as codeine ultrametabolizers. These individuals metabolize codeine to morphine at a dangerously fast rate, leading to adverse events and potentially death. As a consequence the Ethiopian Food, Medicine and Health Care Administration and Control Authority has entirely banned the use of codeine as unsafe for the general population.
ACAM2000 is a smallpox vaccine manufactured by Emergent Biosolutions. It provides protection against smallpox for people determined to be at high risk for smallpox infection. ACAM2000 is a live replicating vaccinia virus vaccine. Like other smallpox vaccines, it also works as a vaccine for mpox and was approved for this purpose in 2024.
=== Elimination of graduate tuition assistance to selected schools === In February 2026, Sec. Hegseth announced that the Defense Department would eliminate all graduate-level professional military training, fellowships and certificate programs at Harvard University starting in the fall of 2026 because of the institution's "anti-military bias." In the memo issued by the DoD, Hegseth also said the department would investigate other universities. The memo listed 33 colleges and universities including Princeton, Duke, Columbia, and Carnegie Mellon. The Pentagon stated that service members could gain the same experience from the war colleges, military academies and public universities at lower cost. Opponents say that this could hurt readiness and retention as mid-career officers see the programs as a benefit that can help them in their post-military careers. Georgetown law professor Rosa Brooks stated, "Cutting off their access to the best universities in the country is just plain dumb, and suggests Hegseth thinks officers can't be trusted to bring any critical thinking to their classes and academic work, distinguishing between opinion and fact." On March 2, 2026, the Pentagon released a list of 20 partner institutions that Hegseth says are examples of "intellectual freedom, minimal relationships with adversaries, minimal public expressions in opposition of the Department, and Graduate-level National Security, International Affairs, and/or Public Policy Programs".
Sources: en.wikipedia.org
The letters GHK are the one-letter codes for glycine, histidine and lysine, the three amino acids in the peptide. The suffix Cu indicates that the peptide is bound to a copper ion, normally copper(II).
The free tripeptide and its copper complex have been measured in human plasma, saliva, urine and some tissue extracts. Reported concentrations vary widely between studies, and the role of the complex in normal physiology remains partly unresolved.
The plain peptide lacks the metal, so its charge, colour and binding behaviour differ. The copper complex is blue and carries a bound copper ion, while the metal-free form is colourless and has different solution chemistry.
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.