Everything below concerns glycyl-histidyl-lysine. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Stability of the complex in solution depends on pH, temperature, and the presence of competing ligands. It is generally described as more resistant to breakdown than the metal-free chain, since coordination reduces susceptibility to enzymatic attack. Oxidation and hydrolysis can nevertheless proceed over time in aqueous media. Storage guidance in laboratory settings commonly involves refrigeration, protection from light, and avoidance of strongly alkaline conditions. Published data on long-term behaviour vary considerably and depend on the specific matrix.
Handling practices for the solid material emphasise low temperature and dryness. The lyophilised or powdered form is typically kept at refrigerator or freezer temperatures together with a desiccant. Working solutions are often prepared fresh, because repeated freeze-thaw cycles and extended storage may alter the complex. Glass or inert plastic containers are preferred over materials that could leach metal ions into the preparation. Such practices follow general peptide conventions rather than substance-specific regulations.
| 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 |
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.
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.
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.
Copper content is measured separately, since a peptide assay alone does not report the metal-to-peptide ratio. Elemental techniques such as inductively coupled plasma optical emission spectroscopy quantify copper after acid digestion of the sample. The result is compared with the theoretical value for a one-to-one complex, and a shortfall indicates free peptide or partial dissociation. Suppliers differ in how they state purity, as some quote peptide content and others quote the whole complex. A defined stoichiometry therefore requires both a peptide assay and a copper assay.
Solid GHK-Cu is usually supplied as a lyophilized powder and is kept cold and dry. Moisture, light, and repeated temperature cycling shorten its useful life in the laboratory. In aqueous solution the complex undergoes slow hydrolysis of the peptide backbone and gradual loss of coordinated copper. Buffers containing strong chelators, such as EDTA, compete for the metal and strip it from the peptide. Working solutions are therefore prepared shortly before use, and leftover liquid is not returned to the stock container.
Supergrade 2–3% Weapons grade 3–7% Fuel grade 7–18% Reactor grade 18% or more A nuclear reactor that is used to produce plutonium for weapons therefore generally has a means for exposing 238U to neutron radiation and for frequently replacing the irradiated 238U with new 238U. A reactor running on unenriched or moderately enriched uranium contains a great deal of 238U. However, most commercial nuclear power reactor designs require the entire reactor to shut down, often for weeks, in order to change the fuel elements. They therefore produce plutonium in a mix of isotopes that is not well-suited to weapon construction. Such a reactor could have machinery added that would permit 238U slugs to be placed near the core and changed frequently, or it could be shut down frequently, so proliferation is a concern; for this reason, the International Atomic Energy Agency inspects licensed reactors often. A few commercial power reactor designs, such as the reaktor bolshoy moshchnosti kanalniy (RBMK) and pressurized heavy water reactor (PHWR), do permit refueling without shutdowns, and they may pose a proliferation risk. By contrast, the Canadian CANDU heavy-water moderated, natural-uranium fueled reactor can also be refueled while operating, but it normally consumes most of the 239Pu it produces in situ; thus, it is not only inherently less proliferative than most reactors, but can even be operated as an "actinide incinerator".
planets in the habitable zones of stars with low metallicity are the best targets to search for complex life on land." A university reports a study (29 Mar) affirming the high level of economic losses from biological invasions, showing they have risen to the level of economic damage costs from floods or earthquakes, which are also rising. 19 April A bolide is observed over Ukraine and Belarus for about five seconds. It is first observed at an altitude of 98 km above Velyka Dymerka, then passes directly above Kyiv at an altitude of 80 km and continues to the southwest with a speed of 29 km/s. A bright flare occurs at an altitude of 38 km, when the bolide's absolute magnitude reaches approximately −18. The likely cause of grey hair is shown to be pigment-making cells losing their ability to mature into melanocytes. Researchers show parrots can and enjoy to use a videocalling system. A study with mice shows that microplastics pass the blood–brain barrier (BBB), entering and accumulating in the brain, and identifies a key determinant for whether or not they pass the BBB. 20 April A new 29-year record of ice sheet mass in Greenland and Antarctica is published as part of the IMBIE collaboration. It finds that the combined ice loss in these regions has more than tripled since the early 1990s, with 2019 seeing the greatest losses of any year on record. These findings have implications for future sea level rise.
== Bone balance == Acidosis inhibits bone osteoblast matrix mineralization with reciprocal effect on osteoclast activation. The combined responses of these cells to acidosis maximizes the availability of hydroxyl ions in solution that can be used to buffer protons. The utilization of bone to buffer even a small percentage of daily acid production can lead to significant loss of bone mass in the course of a decade. Additionally, as the body ages there is a steady decline in renal function. Metabolic acidosis can become more severe as kidney function weakens, and the body will depend more heavily on bone and blood to maintain acid-base homeostasis.
Sources: en.wikipedia.org
=== Cited texts === Benjamin, Denis R. (1995). Mushrooms: Poisons and Panaceas—A Handbook for Naturalists, Mycologists and Physicians. New York: WH Freeman and Company. ISBN 978-0-7167-2600-5. Jordan, Peter; Wheeler, Steven (2001). The Ultimate Mushroom Book. London: Hermes House. ISBN 978-1-85967-092-7. Zeitlmayr, Linus (1976). Wild Mushrooms: An Illustrated Handbook. Hertfordshire: Garden City Press. ISBN 978-0-584-10324-3.
== In non-exponential decay == The term "half-life" is almost exclusively used for decay processes that are exponential (such as radioactive decay or the other examples above), or approximately exponential (such as biological half-life discussed below). In a decay process that is not even close to exponential, the half-life will change dramatically while the decay is happening. In this situation it is generally uncommon to talk about half-life in the first place, but sometimes people will describe the decay in terms of its "first half-life", "second half-life", etc., where the first half-life is defined as the time required for decay from the initial value to 50%, the second half-life is from 50% to 25%, and so on.
The amylin receptors (AMYRs) are a family of 3 receptors that are activated by amylin, a peptide hormone secreted together with insulin. They are each composed of a copy of the calcitonin receptor (CTR) bound to a receptor activity-modifying protein (RAMP), forming a heterodimer. They consist of AMY1 (RAMP1 with CTR), AMY2 (RAMP2 with CTR), and AMY3 (RAMP3 with CTR). Activation of these receptors appears to have a number of effects on eating behavior, including triggering feelings of satiation, reducing food intake, decreasing fat storage, and increasing energy usage. These effects have led to research into targeting these receptors with treatments for metabolic diseases and obesity. The amylin receptors are G protein-coupled receptor of the secretin receptor family. Consistent with their calcitonin receptor subunit, they appear to activate Gs alpha subunit pathways, and there have also been reports of Gq alpha subunit coupling. However, methodological difficulties related to amylin’s ability to bind with the calcitonin receptor have led some researchers to express uncertainty about these results.
=== Advantages and disadvantages === A fever response to an infectious disease is generally regarded as protective, whereas fever in non-infections may be maladaptive. Studies have not been consistent on whether treating fever generally worsens or improves mortality risk. Benefits or harms may depend on the type of infection, health status of the patient and other factors. Studies using warm-blooded vertebrates suggest that they recover more rapidly from infections or critical illness due to fever. In sepsis, fever is associated with reduced mortality.
Sources: en.wikipedia.org
=== Breastfeeding === ACE inhibitors may be used with caution during breastfeeding due to evidence showing small amounts being present in breastmilk. Enalapril is most commonly prescribed and has the most data published. The medications are considered safe for the mother.
Naram-Sin's Victory Stele depicts him as a god-king (symbolized by his horned helmet) climbing a mountain above his soldiers, and his enemies, the defeated Lullubi led by their king Satuni. The stele was broken off at the top apparently when it was carried away from Sippar and carried off by the Elamite forces of Shutruk-Nakhunte in the 12th century BC along with a number of other monuments. The stele seems to break from tradition by using successive diagonal tiers to communicate the story to viewers, however the more traditional horizontal frames are visible on smaller broken pieces. It has been suggested that it contains the first depictions of battle standards and plate armor. The stele is 2 meters tall and 1.05 meters wide and is made from pinkish limestone. For contrast, see the Victory Stele of Rimush over Lagash or the Victory stele of Sargon. The stele was found by Jacques de Morgan at Susa, and is now in the Louvre Museum (Sb 4). The inscription over the head of the king is in the Akkadian language and very fragmentary, but reads:
MFAP4 (microfibril-associated glycoprotein 4) is an extracellular matrix protein encoded by the MFAP4 gene. It is part of the MFAP family of proteoglycans, which are involved in cell adhesion, intercellular interactions and the assembly and/or maintenance of elastic fibres. MFAP4 is known to co-localise at sites rich in elastic fibres and is thought to interact with several proteins including FBN1, FBN2, tropoelastin and desmosine. It has a relatively non-specific tissue expression pattern, with higher levels observed in organs such as the lungs and vasculature.
Ag+(aq) + 2 NH3(aq) ⇌ Ag(NH3)2+ AgCl(s) ⇌ Ag+(aq) + Cl−(aq) If these reactions both occurred in the same reaction vessel, the solubility of the silver chloride (AgCl) would be increased by the presence of NH3 because formation of the diammineargentum(I) complex (Ag(NH3)2+) consumes a significant portion of the free silver ions from the solution. By Le Chatelier's principle, this causes the equilibrium reaction for the dissolving of the silver chloride, which has silver ion as a product, to shift to the right. This new solubility can be calculated given the values of Kf and Ksp for the original reactions. The solubility is found essentially by combining the two separate equilibria into one combined equilibrium reaction and this combined reaction is the one that determines the new solubility. So Kc, the new solubility constant, is denoted by:
On September 28 Hanmi and Zentec Pharmaceuticals agreed that Zentec would market Hanmi's small molecule cancer drug candidate, HM95573; Zentec paid $80 million upfront, with $830 million in milestones, and royalties. On September 29, Hanmi and Roche's cancer subsidiary Genentech announced a deal for Hanmi's Phase I cancer drug candidate, HM95573, which targets the MAPK/ERK pathway; Roche agreed to pay $80 million upfront, and the deal included $830 million in milestones. In December 2016 the Sanofi deal was reduced in scope, with Hanmi receiving back rights to the once-weekly insulin and the combination GLP1-RA/insulin product, and agreeing to repay Sanofi $250 million of the $434 million upfront payment. On December 3, 2019, Rapt Therapeutics and Hanami Pharmaceutical announced collaboration to develop and commercialize FLX475 in Asia. FLX475 is an oral, small molecule CCR4 antagonist in development for the treatment of multiple cancers. In August 2020, chairman and founder of Hanmi Pharmaceutical Lim Sung-ki died of a chronic disease. He was 80. On May 15, 2023, Athenex, which was Hanmi's U.S. partner for its anticancer product, Oraxol, filed for Chapter 11 bankruptcy protection.
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection is the most common approach. Purity is expressed as a share of total peak area at a specified wavelength. Mass spectrometry is then used to confirm molecular identity.