A practical reference on Gly-His-Lys: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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 International Nomenclature of Cosmetic Ingredients lists the substance as copper tripeptide-1, the name that appears on most topical product labels. Related designations include copper peptide and GHK-Cu, and the hyphenated form is common in research literature. In cosmetics the material is regulated as an ingredient rather than as a drug, so products may reach the market without evidence of the effects claimed for them. Whether those effects are clinically meaningful is an open question, since most supportive data come from laboratory work and small trials.
GHK-Cu is the copper complex of the tripeptide glycyl-L-histidyl-L-lysine, a short sequence found naturally in human plasma, saliva and urine. Loren Pickart reported the isolation of the free peptide in 1973 while studying factors that influenced the growth of aged liver cells in culture. The peptide was later shown to bind copper(II) with high affinity, and the metal-bound form became the focus of most subsequent research. Its concentration in circulation declines markedly with age, a pattern that is well documented, though the physiological consequences of that decline remain debated.
| 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 |
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.
Laboratory studies describe GHK-Cu as a source of copper that cells can take up, with reported effects on collagen, elastin, and glycosaminoglycan synthesis in cultured fibroblasts. The peptide also appears in wound-repair research, where it is linked to the activity of matrix metalloproteinases and their inhibitors. These observations come largely from cell and animal models. How directly the complex controls any single pathway in intact human skin remains an open question, and reported effects depend on concentration, vehicle, and exposure time.
Copper takes part in redox chemistry, and the same property that makes it useful in enzymes can generate reactive oxygen species when the ion is loosely bound. GHK chelates copper through imidazole, amino, and amide nitrogen donors, which reduces the amount of free copper in solution. Whether that chelation is protective, neutral, or harmful in a given tissue is not settled. Laboratory assays report both antioxidant and pro-oxidant behavior, depending on the conditions and the readout used.
==== Transformation of kerogen into fossil fuels ==== Kerogen formation continued to a depth of about 1 km from the Earth's surface where temperatures may reach around 50 °C. Kerogen formation represents a halfway point between organic matter and fossil fuels: kerogen can be exposed to oxygen, oxidize and thus be lost, or it could be buried deeper inside the Earth's crust and be subjected to conditions which allow it to slowly transform into fossil fuels like petroleum. The latter happened through catagenesis in which the reactions were mostly radical rearrangements of kerogen. These reactions took thousands to millions of years, and no external reactants were involved. Due to the radical nature of these reactions, kerogen reacted towards two classes of products: those with low H/C ratio (anthracene or products similar to it) and those with high H/C ratio (methane or products similar to it); i.e., carbon-rich or hydrogen-rich products. Because catagenesis was closed off from external reactants, the resulting composition of the fuel mixture was dependent on the composition of the kerogen via reaction stoichiometry. Three types of kerogen exist: type I (algal), II (liptinic) and III (humic), which were formed mainly from algae, plankton and woody plants (this term includes trees, shrubs and lianas) respectively.
For services to Science. Roberta Diane Turley, lately Private Secretary, Nuclear Electric plc. For services to the Electricity Industry. Jean Venables, Director, Venables Consultancy Services. For services to Civil Engineering. Beryl Vickerton, Clerk, Atwick Parish Council. For services to Local Government. Christina Mary Waddell. For services to Victim Support and to Carers of Disabled People in Stirling. John Hill Waddell, lately Her Majesty's Inspector of Immigration for Scotland and Northern Ireland, Home Office. Peter Waddington. For services to the community in Downton, Wiltshire. Ann Cunningham Wagstaff, Executive Officer, Ministry of Defence. Geoffrey James George Wakeling, Senior Engineer, Leicestershire County Council. For services to Highways Improvement. Graham Basil Walker, Coxswain/Mechanic, Wells Lifeboat, Norfolk. For services to the Royal National Lifeboat Institution. Mary Walker, Chairman, General Committee of the Christie Hospital and Holt Radium Institute Women's Trust Fund. For charitable services. Nancy Hamilton Walker, Editor, Kinross Newsletter. For services to the community in Kinross-shire. Patricia Ann Walker, Valuation Referencer, Board of Inland Revenue. Sheila Mary Walker. For charitable services. Freda Inez Walley. For services to the community, particularly Prisoner Welfare, in Walsall. Valerie Ann Wallis, Vice-Chairman, Young Men's Christian Association. For services to Young People in Kent. John Wardrobe. For services to Association Football for Young People.
Oftentimes, for women treating acne, spironolactone is prescribed and paired with a birth control pill. Positive results in the pairing of these two medications have been observed, although these results may not be seen for up to three months. Spironolactone has been reported to produce a 50 to 100% improvement in acne at sufficiently high doses. Response to treatment generally requires 1 to 3 months in the case of acne and up to 6 months in the case of hirsutism. Ongoing therapy is generally required to avoid relapse of symptoms. Spironolactone is commonly used in the treatment of hirsutism in women, and is considered to be a first-line antiandrogen for this indication. Spironolactone can be used in the treatment of female-pattern hair loss (pattern scalp hair loss in women). There is tentative low quality evidence supporting its use for this indication. Antiandrogens such as spironolactone are male-specific teratogens, which can feminize male fetuses due to their antiandrogenic effects. For this reason, antiandrogens are recommended only to be used to treat women who are of reproductive age in conjunction with adequate contraception. Oral contraceptives, which contain an estrogen and a progestin, are typically used for this purpose. Moreover, oral contraceptives themselves are functional antiandrogens and are independently effective in the treatment of androgen-dependent skin and hair conditions, hence can significantly augment the effectiveness of antiandrogens in the treatment of such conditions.
The head of the Wagner Group, Yevgeny Prigozhin, said that he would withdraw his troops from Bakhmut after Russia's Victory Day on 10 May because of ammunition shortages, blaming the Russian military establishment. However, two days later he said he had "received a combat order" and had been promised all ammunition and weapons needed. Russia ordered a partial evacuation of civilians from 18 settlements of Zaporizhzhia Oblast near the Zaporizhzhia Nuclear Power Plant, including Enerhodar, citing increased shelling by the Ukrainian military. A Polish border guard aircraft on patrol for the European Union's border agency Frontex figured in a near-collision with a Russian Su-35 fighter jet in international waters over the Black Sea near Romania. A Polish official said that the Russian jet carried out "aggressive and dangerous manoeuvres" approaching the Polish aircraft without keeping a secure distance, leading to turbulence, loss of altitude and a temporary loss of control of the plane by the crew. Belarus implemented border controls with Russia for the first time since 1995, in what Foreign Minister Sergei Aleinik later said was part of efforts to avoid the entry of third-country nationals into the country but was seen by human rights organizations as an attempt to stem the escape of Russian dissidents and draft evaders.
=== Wound Healing Center === The SOMC Wound Healing Center treats diabetic ulcers, lower leg ulcers, press ulcers, bone infection, gangrene, skin tears or lacerations, radiation burns, post-operation wounds and infections and failed or compromised skin grafts. Services offered include:
Sources: en.wikipedia.org
In general, polymeric mixtures are far less miscible than mixtures of small molecule materials. This effect results from the fact that the driving force for mixing is usually entropy, not interaction energy. In other words, miscible materials usually form a solution not because their interaction with each other is more favorable than their self-interaction, but because of an increase in entropy and hence free energy associated with increasing the amount of volume available to each component. This increase in entropy scales with the number of particles (or moles) being mixed. Since polymeric molecules are much larger and hence generally have much higher specific volumes than small molecules, the number of molecules involved in a polymeric mixture is far smaller than the number in a small molecule mixture of equal volume. The energetics of mixing, on the other hand, is comparable on a per volume basis for polymeric and small molecule mixtures. This tends to increase the free energy of mixing for polymer solutions and thereby making solvation less favorable, and thereby making the availability of concentrated solutions of polymers far rarer than those of small molecules. Furthermore, the phase behavior of polymer solutions and mixtures is more complex than that of small molecule mixtures.
English is the official language of Belize, a legacy of its former status as a British colony. Belize is the only country in Central America with English as the official language. English is the primary language of public education, government, and most media outlets. Although English is widely used, Belizean Creole is spoken in several situations, whether informal, formal, social, or interethnic dialogue, even in meetings of the House of Representatives. When a creole language exists alongside its lexifier language, as is the case in Belize, a continuum forms between the creole and the lexifier language. Approximately 52.9% of Belizeans self-identify as Mestizo or Hispanic. When Belize was a British colony, Spanish was banned in schools, but since then it has become widely spoken. "Kitchen Spanish" is an intermediate form of Spanish mixed with Belize Creole, spoken in the northern districts. Some good examples are Corozal and San Pedro. Over half the population is multilingual, owing to Belize's status as a small, multiethnic state, surrounded by Spanish-speaking nations. Belize is also home to three Mayan languages: Q'eqchi', Mopan (an endangered language), and Yucatec Maya. Approximately 7,481 people speak the Arawakan-based Garifuna language, and in the mid-1990s about 6,900 Mennonites in Belize spoke Plautdietsch while a minority of Mennonites spoke Pennsylvania Dutch.
=== Surgery === Surgery for back pain is typically used as a last resort, when serious neurological deficit is evident. A 2009 systematic review of back surgery studies found that, for certain diagnoses, surgery is moderately better than other common treatments, but the benefits of surgery often decline in the long term. Surgery may sometimes be appropriate for people with severe myelopathy or cauda equina syndrome. Causes of neurological deficits can include spinal disc herniation, spinal stenosis, degenerative disc disease, tumor, infection, and spinal hematomas, all of which can impinge on the nerve roots around the spinal cord. There are multiple surgical options to treat back pain, and these options vary depending on the cause of the pain. When a herniated disc is compressing the nerve roots, hemi- or partial-laminectomy or discectomy may be performed, in which the material compressing on the nerve is removed. A multi-level laminectomy can be done to widen the spinal canal in the case of spinal stenosis. A foraminotomy or foraminectomy may also be necessary, if the vertebrae are causing significant nerve root compression. A discectomy is performed when the intervertebral disc has herniated or torn. It involves removing the protruding disc, either a portion of it or all of it, that is placing pressure on the nerve root. Total disc replacement can also be performed, in which the source of the pain (the damaged disc) is removed and replaced, while maintaining spinal mobility.
== Further reading == Arthur, Joyce (1996). "Creationism: Bad Science or Immoral Pseudoscience?". Skeptic. 4 (4): 88–93. Archived from the original on March 7, 2012. Montagu, M. F. Ashley, ed. (1984-01-12). Science and Creationism (Kindle ed.). USA: Oxford University Press. ASIN B000QXDJIG. Nelkin, Dorothy (2000) [1986]. The Creation Controversy: Science or Scripture in the Schools. toExcel. ISBN 0-595-00194-7. Numbers, Ronald L. (2006). The Creationists: From Scientific Creationism to Intelligent Design (expanded ed.). Harvard. ISBN 978-0-674-02339-0.
Sources: en.wikipedia.org
Brazil is the world's eleventh-largest energy consumer. Much of its energy comes from renewable sources, particularly hydroelectricity and ethanol; the Itaipu Dam is the world's largest hydroelectric plant by energy generation, and the country has other large plants such as Belo Monte and Tucuruí. The first car with an ethanol engine was produced in 1978 and the first airplane engine running on ethanol in 2005. At the end of 2021, Brazil ranked second in the world by installed hydroelectric power (109.4 GW) and biomass (15.8 GW), seventh in installed wind power (21.1 GW) and 14th in installed solar power (13.0 GW)—on track to also become one of the top 10 in the world in solar energy. At the end of 2024, Brazil was the fourth largest producer of wind energy in the world (107.8 TWh), behind only China, the United States and Germany, and the world's fifth largest producer of solar energy (74.7 TWh). Overall, Brazil ranks third globally in renewable electricity production, after China and the United States, accounting for 7% of the global total. The Brazilian energy matrix is characterized by a higher degree of renewable energy than the global average; in 2022, the world energy matrix was only 14% renewable energy, compared to 45% in Brazil. Petroleum and oil products made up 34.3% of the country's matrix; sugar cane derivatives, 18%; hydraulic energy, 12.4%; natural gas, 12.2%; firewood and charcoal, 8.8%; varied renewable energies, 7%; mineral coal, 5.3%; nuclear, 1.4%, and other non-renewable energies, 0.6%.
From 1980 to 2013, the prevalence of overweight and obesity in children increased by nearly 50%. Currently 10% of children worldwide are either overweight or obese. In 2014, the World Health Organization established a high-level commission to end childhood obesity. With more than 42 million overweight children around the world, childhood obesity is increasing worldwide. Since 1980, the number of obese children has doubled in all three North American countries – Mexico, the United States, and Canada. Although the rate of childhood obesity in the United States has stopped increasing, the current rate remains high. In 2010, 32.6 percent of six- to eleven-year-olds were overweight, and 18 percent of six- to nine-year-olds were obese.
=== Polymerization === The polymer formed by linking thiophene through its 2,5 positions is called polythiophene. Polymerization is conducted by oxidation using electrochemical methods (electropolymerization) or electron-transfer reagents. An idealized equation is shown:
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.
It is a complex of a three-amino-acid peptide, glycine, histidine and lysine, bound to a single copper(II) ion. The metal is held mainly by the histidine side chain and the peptide backbone. Most commercial material is supplied as an acetate salt rather than as the free complex.