If you have been reading about glycyl-histidyl-lysine and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-04-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 |
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.
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 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.
== Prognosis == SJS (with less than 10% of body surface area involved) has a mortality rate of around 5%. The mortality for toxic epidermal necrolysis (TEN) is 30–40%. The risk for death can be estimated using the SCORTEN scale, which takes a number of prognostic indicators into account. It is helpful to calculate a SCORTEN within the first 3 days of hospitalization. Other outcomes include organ damage/failure, ocular morbidity, and blindness. Restrictive lung disease may develop in patients with SJS and TEN after initial acute pulmonary involvement. Patients with SJS or TEN caused by a drug have a better prognosis the earlier the causative drug is withdrawn.
Moreover, engineered knottins have shown significant promise as therapeutics, imaging agents, and targeting agents for chemotherapy. The mammalian proteins Agouti signalling peptide and Agouti related peptide are the only known mammalian examples of this motif. Both are neuropeptides involved in cell signalling. The former is responsible for hair (fur) colouration. The motif is similar to the cyclic cystine knot or cyclotide, but lacks the cyclisation of the polypeptide backbone which is present in the latter family. The growth factor cystine knot (GFCK) is similar to the ICK but its topology is such that it is the bond between the first and fourth disulfide which threads through the loop.
== Additional functions == The ILEA had its own schools broadcasting service, the Educational Television Service, based in the former Tennyson Secondary School, Thackeray Road, SW8. The television centre had two functional television studios, a training studio, a master control and sound and vision mixing suites. At one stage this was believed to be the largest closed-circuit television system in the world. The first transmission took place on 16 September 1969 and the Television Service ran until 1977. When the Post Office, whose cabling was used for the distribution, wanted to withdraw from its contract in the late 1970s, the programming was transferred to VHS tapes and the CCTV network closed down. The Cockpit Theatre, Marylebone (also known at the Cockpit Youth and Arts Centre), in Gateforth Street, London, NW8, was built for the ILEA on the edge of the Lisson Green estate in 1969–70. It was designed as a Theatre in the round by Edward Mendelsohn. The ILEA created the first Theatre in Education company to be entirely housed within a local education authority. It employed seven actor-teachers and a stage manager and focused its work on secondary schools and Further Education. As well as traditional T.I.E. the Cockpit team used the approach to develop shows analysing set texts. When ILEA was abolished in 1990, ownership of the theatre transferred to the London Borough of Westminster. The ILEA had a planetarium, based at Wandsworth School. It was opened by the Astronomer Royal Sir Richard Woolley on 19 May 1966.
=== Labour === Tea production in Kenya, Malawi, Rwanda, Tanzania, and Uganda uses child labour, according to the U.S. Department of Labor's List of Goods Produced by Child Labor or Forced Labor. Workers who pick and pack tea on plantations in developing countries can face harsh working conditions and may earn below the living wage. In countries such as Bangladesh, trade unions such as the Bangladesh Tea Workers Women's Forum, led by Gita Rani Kanu, have emerged to campaign for better working conditions for tea workers.
Sources: en.wikipedia.org
== Applications == The body of research on the effectiveness of current PRRT is promising, but limited. Complete or partial treatment response has been seen in 20-30% of patients in trials treated with 177Lu-DOTATATE or 90Y-DOTATOC, among the most widely used PRRT drugs. When it comes to comparing these two PRRT, Y-labeled and Lu-labeled PRRTs, it appears that Y-labeled is more effective for larger tumors, while Lu-labeled is better for smaller and primary tumors. The lack of γ-emission with Y-labeled PPRTs is also an important difference between Lu peptides and Y peptide. In particular, with Y-labeled PRRT it becomes difficult to set up a dose of radiations specific to the patient's needs. In most cases PRRT is used for cancers of the gastroenteropancreatic and bronchial tracts, and in some cases phaeochromocytoma, paraganglioma, neuroblastoma or medullary thyroid carcinoma. Various approaches to approve effectiveness and limit side effects are being investigated, including radiosensitising drugs, fractionation regimes and new radionuclides. Alpha emitters, which have much shorter ranges in tissue (limiting the effect on nearby healthy tissue), such as bismuth-213 or actinium-225 labelled DOTATOC are of particular interest. A comparative cohort study of 1051 neuroendocrine tumor patients undergoing 90Y-DOTATOC (n=910) or 177Lu-DOTATOC (n=141) reported no significant difference in overall survival between the groups.
Immediately after the 1948 war, the Israel-Palestinian conflict shifted to a low intensity conflict between the IDF and Palestinian fedayeen. In the 1956 Suez Crisis, the IDF's first serious test of strength after 1949, the new army captured the Sinai Peninsula from Egypt, which was later returned. In the 1967 Six-Day War, Israel conquered the Sinai Peninsula, Gaza Strip, West Bank (including East Jerusalem) and Golan Heights from the surrounding Arab states, changing the balance of power in the region as well as the role of the IDF. In the following years leading up to the Yom Kippur War, the IDF fought in the War of Attrition against Egypt in the Sinai and a border war against the Palestine Liberation Organization (PLO) in Jordan, culminating in the Battle of Karameh. The surprise of the Yom Kippur War and its aftermath completely changed the IDF's procedures and approach to warfare. Organizational changes were made and more time was dedicated to training for conventional warfare. In the following years the army's role slowly shifted again to low-intensity conflict, urban warfare and counter-terrorism. An example of the latter was the successful 1976 Operation Entebbe commando raid to free hijacked airline passengers being held captive in Uganda. During this era, the IDF also mounted a successful bombing mission in Iraq to destroy its nuclear reactor. It was involved in the Lebanese Civil War, initiating Operation Litani and later the 1982 Lebanon War, where the IDF ousted Palestinian guerilla organizations from Lebanon.
Scotland was traditionally divided into four whisky regions: Campbeltown, The Highlands, The Isle of Islay and The Lowlands. Due to the large number of distilleries found there, the Speyside area became the fifth, recognised by the Scotch Whisky Association (SWA) as a distinct region in 2014. The whisky-producing islands other than Islay are not recognised as a distinct region by the SWA, which groups them into the Highlands region.
Sources: en.wikipedia.org
Counter-Strike: Source was the first game publicly released by Valve to run on the Source engine. Counter-Strike: Source was initially released as a beta to members of the Valve Cyber Café Program on August 11, 2004. On August 18, 2004, the beta was released to owners of Counter-Strike: Condition Zero and to those who had bought ATI Radeon video cards bundled with a Half-Life 2 voucher. While the original release only included a version for Microsoft Windows, the game eventually received a port to OS X on June 23, 2010, with a Linux port afterwards in 2013.
=== A10BX Other blood glucose lowering drugs, excluding insulins === A10BX01 Guar gum A10BX02 Repaglinide A10BX03 Nateglinide A10BX05 Pramlintide A10BX06 Benfluorex A10BX08 Mitiglinide A10BX15 Imeglimin A10BX16 Tirzepatide A10BX17 Carfloglitazar A10BX18 Dorzagliatin
Mirror-image life (also called mirror life) is a hypothetical form of life using mirror-reflected molecular building blocks. The successful creation of mirror-image life had previously been the goal of some scientists as a scientific achievement and a potential tool for biomanufacturing of mirror-image molecules. In 2024, a team of 38 scientists, including two Nobel laureates and several researchers previously involved in developing mirror-image life, published a report suggesting that mirror-image life could pose catastrophic risks to health and the environment. Unlike simple mirror-image molecules, mirror-image organisms such as bacteria could reproduce and might irreversibly spread through ecosystems. Such bacteria might be able to evade many components of immune systems, causing fatal infections in humans, animals, and plants. Some scientists, bioethicists, policymakers, and civil society groups have recommended that governance be established to ensure that mirror-image life is not created, and some funders have refused to support research with the goal of creating mirror-image life. Discussions are ongoing about the risks of mirror life and appropriate governance. Certain mirror-image components of molecular machinery have been synthesized in laboratories and efforts to chemically synthesize a mirror-image ribosome have been ongoing since 2016. Although entire mirror organisms could in principle be created, some scientists estimate 10 to 30 years before the creation of mirror-image life is possible.
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.
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.