The short version of Gly-His-Lys fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-07-27 and is reviewed periodically as new material appears.
The peptide portion consists of three amino acids: glycine, histidine and lysine. Copper(II) coordinates through the imidazole nitrogen of histidine, the alpha-amino group of glycine and a deprotonated amide nitrogen of the backbone, producing a roughly square-planar geometry. This arrangement gives the complex its characteristic blue-to-violet colour and helps it resist dissociation in water. Reported stability constants are high, although values differ between studies because of differences in ionic strength and measurement method.
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.
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.
Analytical confirmation usually combines a separation method with a copper-specific measurement. Liquid chromatography or mass spectrometry establishes peptide identity and purity, while an elemental measurement quantifies the metal content. A frequent misconception is that any blue solution contains an intact copper peptide complex; color alone does not confirm structure, because free copper salts and degraded mixtures can also appear colored. Literature on efficacy is mixed, with in vitro findings often more dramatic than human evidence, and reviews note small sample sizes and short follow-up. Open questions include optimal concentration, skin penetration, and long-term effects.
| Property | Value | Notes |
|---|---|---|
| INCI name | Copper tripeptide-1 | Standard designation on cosmetic ingredient labels |
| Peptide sequence | Gly-His-Lys | Three-residue ligand; binding occurs at the histidine side chain |
| Metal-to-peptide ratio | 1 to 1 | One copper(II) ion per peptide unit |
| Appearance | Blue to violet powder | Colour arises from copper-to-peptide electronic transitions |
| Water solubility | Freely soluble | Commonly formulated in aqueous or water-alcohol systems |
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.
Research interest in GHK-Cu centers on its ability to deliver copper and to influence cellular processes in laboratory models. In cell culture and animal studies, the complex has been linked to collagen synthesis, antioxidant enzyme activity, and expression of genes associated with tissue remodeling. These effects are not equivalent to proven clinical outcomes. The mechanisms proposed include copper transfer to cuproenzymes, modulation of growth factor signaling, and interactions with extracellular matrix components. How much of the observed activity depends on intact GHK-Cu versus free copper or free peptide is not fully resolved.
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.
Solid GHK-Cu is generally stored as a dry powder under frozen conditions to limit degradation. The peptide bond can hydrolyze, and the copper center can be displaced by strong chelators such as EDTA. Aqueous solutions are less stable than the solid and may lose color or form precipitates over time. Temperature, pH, and oxygen exposure are the main variables that affect shelf life. Neutral to slightly acidic conditions tend to preserve the complex better than strongly alkaline media.
Routine handling calls for minimizing freeze-thaw cycles and preparing solutions shortly before use. Glass or inert plastic containers reduce adsorption and metal leaching. Working stocks are often kept at 2–8 °C for short periods, while long-term reference material stays at −20 °C or below. Light protection is prudent because prolonged exposure may accelerate oxidation of the peptide. Documentation of lot number, concentration, and preparation date supports reproducibility in laboratory work.
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 now called GHK was first reported in the early 1970s after isolation from human plasma, where it was noted to influence liver cell behavior in laboratory preparations. Later work described a copper-binding form and its activity in fibroblast and wound-model experiments. Review articles frequently group the substance with other copper peptides. Concentrations in blood appear to fall with age in several small surveys, although the reason for this trend is not settled. Whether such a decline carries functional consequences remains an open question.
== Toxicity == The toxicity of organomercury compounds presents both dangers and benefits. Dimethylmercury in particular is notoriously toxic, but found use as an antifungal agent and insecticide. Merbromin and phenylmercuric borate are used as topical antiseptics, while thimerosal is safely used as a preservative for vaccines and antitoxins.
=== 24 May === Ukrainian authorities ordered the mandatory evacuation of 123 children from 36 settlements in Kharkiv Oblast due to Russian attacks. The United States sent another military aid package for Ukraine, valued at $275 million. It included HIMARS, munitions, 155 mm and 105 mm high-demand artillery rounds, Javelin and AT4 antitank systems, antitank mines, tactical vehicles, small arms and ammunition. The Ukrainian Air Force announced that it had begun using air dropped Small Diameter Bombs, which had "proved resilient to jamming" and had a "nearly 90 percent" accuracy rate, since November 2023.
Conway dissuades members of the fandom, and Anthrocon membership in particular, from responding to the mass media and news media, due in part to sensationalist coverage like the 2001 Vanity Fair article in which he was quoted. In 2003 he said his standard response to the media was: "Anthrocon is a private event held on private property. Its membership is not interested in being the subject of your documentary." However, Conway relaxed this stance with Anthrocon's move to Pittsburgh in 2006. While no television, magazine or tabloid representatives were present, several newspapers were invited to attend, and did, including the Pittsburgh Tribune-Review, the Pittsburgh Post-Gazette, and the Pittsburgh City Paper, which printed both a preview and an extensive review. When local television station KDKA-TV showed up, Conway gave a short television interview outside the convention hotel. In November 2006 he gave a radio interview to Dublin's 98FM. Anthrocon still retains tight control over media access, not only to the convention grounds but to the membership, and has official policy that forbids unmonitored dealings with unauthorized members of the media.
Sources: en.wikipedia.org
== Other deposits == In Poland diatomaceous earth deposits are found in Jawornik, and are composed mostly of diatomaceous skeletons (frustules). In Germany, diatomaceous earth was also extracted at Altenschlirf on the Vogelsberg (Upper Hesse) and at Klieken (Saxony-Anhalt). There is a layer of diatomaceous earth more than 6 meters (20 ft) thick in the nature reserve of Soos in the Czech Republic. Deposits on the Isle of Skye, off the west coast of Scotland, were mined until 1960. In Colorado and in Clark County, Nevada, United States, there are deposits that are up to several hundred meters thick in places. Marine deposits have been worked in the Sisquoc Formation in Santa Barbara County, California near Lompoc and along the Southern California coast. This is the world's largest deposit of diatomite. Additional marine deposits have been worked in Maryland, Virginia, Algeria and the MoClay of Denmark. Freshwater lake deposits occur in Nevada, Oregon, Washington and California. Lake deposits also occur in interglacial lakes in the eastern United States, in Canada and in Europe in Germany, France, Denmark and the Czech Republic. The worldwide association of diatomite deposits and volcanic deposits suggests that the availability of silica from volcanic ash may be necessary for thick diatomite deposits. Diatomaceous earth is sometimes found on desert surfaces. Research has shown that the erosion of diatomaceous earth in such areas (such as the Bodélé Depression in the Sahara) is one of the most important sources of climate-affecting dust in the atmosphere.
Beta cells in the islets of Langerhans release insulin in two phases. The first-phase release is rapidly triggered in response to increased blood glucose levels, and lasts about 10 minutes. The second phase is a sustained, slow release of newly formed vesicles triggered independently of sugar, peaking in 2 to 3 hours. The two phases of the insulin release suggest that insulin granules are present in diverse stated populations or "pools". During the first phase of insulin exocytosis, most of the granules predispose for exocytosis are released after the calcium internalization. This pool is known as Readily Releasable Pool (RRP). The RRP granules represent 0.3-0.7% of the total insulin-containing granule population, and they are found immediately adjacent to the plasma membrane. During the second phase of exocytosis, insulin granules require mobilization of granules to the plasma membrane and a previous preparation to undergo their release. Thus, the second phase of insulin release is governed by the rate at which granules get ready for release. This pool is known as a Reserve Pool (RP). The RP is released slower than the RRP (RRP: 18 granules/min; RP: 6 granules/min). Reduced first-phase insulin release may be the earliest detectable beta cell defect predicting onset of type 2 diabetes. First-phase release and insulin sensitivity are independent predictors of diabetes. The description of first phase release is as follows:
Doses… were subcutaneously injected into young dogs and rabbit… with the following general results… great prostration, fear, and sleepiness speedily following the administration, the eyes being sensitive, and pupils constrict, considerable salivation being produced in dogs, and a slight tendency to vomiting in some cases, but no actual emesis. Respiration was at first quickened, but subsequently reduced, and the heart's action was diminished and rendered irregular. Marked want of coordinating power over the muscular movements, and loss of power in the pelvis and hind limbs, together with a diminution of temperature in the rectum of about 4°.
Sources: en.wikipedia.org
Strontium carbonate and other strontium salts are added to fireworks to give a deep red colour. This same effect identifies strontium cations in the flame test. Fireworks consume about 5% of the world's production. Strontium carbonate is used in the manufacturing of hard ferrite magnets. Strontium chloride is sometimes used in toothpastes for sensitive teeth. One popular brand includes 10% total strontium chloride hexahydrate by weight. Small amounts are used in the refining of zinc to remove small amounts of lead impurities. The metal itself has a limited use as a getter, to remove unwanted gases in vacuums by reacting with them, although barium may also be used for this purpose. The ultra-narrow optical transition between the [Kr]5s2 1S0 electronic ground state and the metastable [Kr]5s5p 3P0 excited state of 87Sr is one of the leading candidates for the future re-definition of the second in terms of an optical transition as opposed to the current definition derived from a microwave transition between different hyperfine ground states of 133Cs. Current optical atomic clocks operating on this transition already surpass the precision and accuracy of the current definition of the second.
=== United States === In May 2020, the company announced their plans to open 350 restaurants in the United States, with their first to be in New Jersey. As of October 2023, the company has since opened nine restaurants within the US. GDK opened their first US restaurant at American Dream in New Jersey in October 2021. In January 2025, German Doner Kebab (GDK) launched its first U.S. advertising campaign titled "Open Your Mouth Mind." The campaign, created by agency Quality Meats, uses quirky visuals and humor to introduce American audiences to GDK’s modern take on the traditional kebab.
=== Sources === The seeds of Ricinus communis are commonly crushed to extract castor oil. As ricin is not oil-soluble, little is found in the extracted castor oil. The extracted oil is also heated to more than 80 °C (176 °F) to denature any ricin that may be present. The remaining spent crushed seeds, called variously the "cake", "oil cake", and "press cake", can contain up to 5% ricin. While the oil cake from coconut, peanuts, and sometimes cotton seeds can be used as cattle feed or fertilizer, the toxic nature of castor beans precludes their oil cake from being used as feed unless the ricin is first deactivated by autoclaving. Accidental ingestion of Ricinus communis cake intended for fertilizer has been reported to be responsible for fatal ricin poisoning in animals. Deaths from ingesting castor plant seeds are rare, partly because of their indigestible seed coat, and because some of the ricin is deactivated in the stomach. The pulp from eight beans is considered dangerous to an adult. Rauber and Heard have written that close examination of early 20th century case reports indicates that public and professional perceptions of ricin toxicity "do not accurately reflect the capabilities of modern medical management". Most acute poisoning episodes in humans are the result of oral ingestion of castor beans, 5–20 of which could prove fatal to an adult. Swallowing castor beans rarely proves to be fatal unless the bean is thoroughly chewed. The survival rate of castor bean ingestion is 98%. In 2013 a 37-year-old woman in the United States survived after ingesting 30 beans.
Sources: en.wikipedia.org
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.
The free peptide was reported in 1973 by Loren Pickart, who isolated it from human plasma. Its copper-binding behaviour was characterised over the following years. The metal-bound form has been the subject of most later research.
Yes. Copper tripeptide-1 is the name used in cosmetic ingredient labelling, while GHK-Cu is the shorthand found in the scientific literature. Both refer to the same peptide-copper complex, and the two terms are interchangeable in most technical documents.
Freezer temperatures are common for long-term retention. Light and moisture exposure should be limited. Working portions are best kept cold and used without repeated freeze-thaw cycles.