Everything below concerns copper tripeptide-1. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-08-30. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II) peptide complex | Coordination compound rather than a simple salt |
| Peptide sequence | Glycyl-L-histidyl-L-lysine | Abbreviated GHK in most literature |
| Molecular formula | C14H22N6O4Cu | Reported for the 1:1 complex |
| Principal binding site | Histidine imidazole nitrogen | Backbone amides contribute additional coordination |
| Common synonym | Copper tripeptide-1 | Used in ingredient and product labelling |
The peptide was first isolated from human albumin in 1973 by Loren Pickart, who later described its copper-binding behavior. Early work linked the complex to wound healing and tissue remodeling. Plasma levels of GHK decline with age, a pattern that stimulated interest in topical and supplemental applications. Researchers have reported that the tripeptide influences collagen synthesis, antioxidant defense, and inflammatory signaling in cell and animal models. Human clinical evidence remains limited and often relies on small studies.
Commercial products list GHK-Cu as copper tripeptide-1, a cosmetic ingredient. Formulators value its blue color and water solubility, which allow incorporation into serums, creams, and masks. Regulatory treatment varies: in the United States it appears in cosmetics, while some jurisdictions classify certain claims as drug-like. The compound is not an approved drug for any indication. Studies continue to examine its effects on skin, hair, and wound repair, but dosage, delivery, and long-term safety questions remain open.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and copper(II). The peptide sequence consists of glycine, histidine, and lysine, and its imidazole and amino groups provide binding sites for the metal ion. In the complex, copper is held through nitrogen donors from the histidine side chain, the N-terminal amine, and deprotonated amide nitrogens. The resulting compound is intensely blue and water-soluble. It occurs naturally in human plasma, saliva, and urine at low concentrations.
Characterizing GHK-Cu requires methods that distinguish the intact complex from free peptide and unbound copper. UV-visible absorption around 600 nm provides a rapid check for copper coordination, while circular dichroism reports on peptide secondary structure. Mass spectrometry confirms the peptide mass and can detect copper adducts under carefully controlled conditions. Electron paramagnetic resonance is particularly informative for Cu(II) because it reveals the ligand field symmetry. No single technique fully defines the complex, so laboratories combine orthogonal methods.
Stability of GHK-Cu in solution depends on pH, temperature, buffer composition, and oxygen exposure. The copper center can undergo reduction or dissociation, especially in the presence of strong metal chelators such as EDTA. Aqueous solutions are often prepared fresh or stored frozen to limit degradation. Lyophilized solid is more stable than liquid formulations, but it can absorb moisture and should be kept dry. Light exposure may also affect copper complexes, though the effect is often modest.
Dry material is normally held cold, commonly at -20 °C for long-term storage and 2 to 8 °C for working quantities, protected from light and moisture. Vials should be allowed to reach room temperature before opening so that condensation does not form on the powder. In liquid formulations the complex is generally kept near neutral to slightly acidic pH, because strongly alkaline conditions favour precipitation of copper hydroxide. Antioxidants or chelate-stabilising excipients are often added, though the specific approaches are proprietary and rarely published in detail.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry to confirm the expected mass. Copper content is measured separately by inductively coupled plasma optical emission spectrometry or atomic absorption spectroscopy, because the peptide assay alone does not establish the metal-to-peptide ratio. Visible spectroscopy provides a rapid check on complex integrity through the absorption band in the visible region. Agreement between the peptide assay and the copper assay is the practical test of whether a sample is the intended complex rather than a mixture.
Aqueous solutions of GHK-Cu are less stable than the dry powder. The peptide backbone is vulnerable to hydrolysis at extreme pH, and copper can be stripped from the complex by strong chelating agents such as EDTA or citrate. Oxidising agents and high concentrations of ascorbic acid can reduce copper(II) and change the complex, which is one reason formulators often keep such ingredients in separate phases. How quickly these changes occur under real storage conditions depends on pH, buffer, temperature and packaging, and quantitative data on the subject are limited.
Laboratory characterization of GHK-Cu typically combines separation, spectroscopic, and elemental techniques. Reverse-phase high-performance liquid chromatography is widely used to assess peptide purity, often with ultraviolet detection near the copper-related absorption band or with mass spectrometry for identity confirmation. Because the molecule contains copper, elemental methods such as inductively coupled plasma mass spectrometry or atomic absorption spectroscopy are used to quantify metal content and confirm stoichiometry. No single universal pharmacopeial monograph exists for GHK-Cu. Laboratories therefore validate their own methods, and reported purity values depend on the chosen assay and calibration standards.
Stability of GHK-Cu is influenced by light, oxygen, moisture, pH, and temperature. Solid material is generally kept desiccated and frozen to reduce hydrolysis and oxidation, while aqueous solutions are best prepared fresh or stored cold in aliquots. Repeated freeze-thaw cycles can promote aggregation, precipitation, or peptide degradation. Copper coordination may change under strongly acidic or alkaline conditions, potentially altering the complex's spectroscopic properties. Published long-term stability data for specific matrices, such as cosmetic emulsions or biological buffers, are limited, so shelf-life claims should be treated as formulation-specific rather than universal.
Quality control for GHK-Cu relies on documentation and independent testing rather than a single accepted standard. A certificate of analysis may report peptide purity, copper content, residual solvents, water content, and microbial limits, but the underlying methods and acceptance criteria vary by supplier. Verification can include mass confirmation, amino acid analysis, and comparison with a reference standard when one is available. Open questions include how different copper-binding modes or peptide isomers affect measured activity and whether conventional purity assays capture those differences. Buyers of research-grade material typically need to request raw data rather than rely solely on a summary certificate.
=== Surgery === Bariatric surgery has also been proposed as another approach to treat BED, and a recent meta-analysis showed that approximately two-thirds of individuals who seek this type of surgery for weight loss purposes have BED. Bariatric surgery recipients who had BED before receiving the surgery tend to have poorer weight-loss outcomes and are more likely to continue to exhibit eating behaviors characteristic of BED.
The growth solution requires a low concentration of a metal precursor, ligands that will readily exchange with preexisting seed ligands, and a weak or very low concentration of reducing agent. The reducing agent must not be strong enough to reduce metal precursor in the growth solution in the absence of seeds. Otherwise, the growth solution will form new nucleation sites instead of growing on preexisting ones (seeds). Growth is the result of the competition between surface energy (which increases unfavorably with growth) and bulk energy (which decreases favorably with growth). The balance between the energetics of growth and dissolution is the reason for uniform growth only on preexisting seeds (and no new nucleation). Growth occurs by the addition of metal atoms from the growth solution to the seeds, and ligand exchange between the growth ligands (which have a higher bonding affinity) and the seed ligands. Range and direction of growth can be controlled by nanoseed, concentration of metal precursor, ligand, and reaction conditions (heat, pressure, etc.). Controlling stoichiometric conditions of growth solution controls ultimate size of particle. For example, a low concentration of metal seeds to metal precursor in the growth solution will produce larger particles. Capping agent has been shown to control direction of growth and thereby shape. Ligands can have varying affinities for binding across a particle. Differential binding within a particle can result in dissimilar growth across particle.
=== March === 1 March 35-year-old Marcus Osborne is given a whole life order, the most severe possible sentence available in England and Wales, for the "sadistic" murders of Steven Harnett and Katie Higton. He receives a further 10-year sentence for the rape and false imprisonment of another woman who was present at the scene, who cannot be named for legal reasons. 29-year-old Joshua Jacques is sentenced to a minimum of 46 years in prison for murdering his girlfriend and three of her family members in a "sacrifice" at their home in Bermondsey, south London, in April 2022. The Met Office reports that England and Wales had their warmest February on record this year, with an average of 7.5 °C recorded for England and 6.9 °C for Wales. Scientists at the Centre for Environment, Fisheries and Aquaculture Science announce the discovery of a new species of sea slug off the southwest coast of England. 2 March The 2024 BRIT Awards take place. Northumberland National Park announces that the Sycamore Gap tree which was illegally felled last September is to go on public display. 4 March The Princess of Wales is photographed for the first time since her surgery, with US celebrity news site TMZ publishing a photo of the princess riding as a passenger in a car being driven by her mother near Windsor Castle. Rumours and conspiracy theories over Catherine's whereabouts have surfaced in recent weeks as she hasn't been seen in public since late December. Cadbury celebrate their 200th anniversary.
A number of invertebrates have lung-like structures that serve a similar respiratory purpose to true vertebrate lungs, but are not evolutionarily related and only arise out of convergent evolution. Some arachnids, such as spiders and scorpions, have structures called book lungs used for atmospheric gas exchange. Some species of spider have four pairs of book lungs but most have two pairs. Scorpions have spiracles on their body for the entrance of air to the book lungs. The coconut crab is terrestrial and uses structures called branchiostegal lungs to breathe air. Juveniles are released into the ocean, however adults cannot swim and possess an only rudimentary set of gills. The adult crabs can breathe on land and hold their breath underwater. The branchiostegal lungs are seen as a developmental adaptive stage from water-living to enable land-living, or from fish to amphibian. Pulmonates are mostly land snails and slugs that have developed a simple lung from the mantle cavity. An externally located opening called the pneumostome allows air to be taken into the mantle cavity lung.
=== Drug-induced obesity === Certain medications may cause weight gain or changes in body composition; these include insulin, sulfonylureas, thiazolidinediones, atypical antipsychotics, antidepressants, steroids, certain anticonvulsants (phenytoin and valproate), pizotifen, and some forms of hormonal contraception.
Sources: en.wikipedia.org
The first woman elected president of a country was Vigdís Finnbogadóttir of Iceland, who won the 1980 presidential election as well as three subsequent elections, remaining in office for a total of 16 years, which makes her the longest-serving non-hereditary female head of state in history. Vigdís was also the first woman to win a presidential election where the second place candidate was another woman: she defeated Sigrún Þorsteinsdóttir in the 1988 presidential election. The first democratically elected female prime minister of a Muslim majority country was Benazir Bhutto of Pakistan, who led her party to victory in the 1988 general election and later in 1993, making her the first woman democratically elected leader of any Muslim nation. Bhutto was also the first of only two non-hereditary female world leaders who gave birth to a child while serving in office, the other being Jacinda Ardern of New Zealand. The longest-tenured female non-hereditary head of government is Sheikh Hasina of Bangladesh. She served as the country's prime minister from June 1996 to July 2001 and again from January 2009 until August 2024, for a combined total of over 20 years. Finland was the first republic in which women served concurrently as both the head of state and head of government, with both Anneli Jäätteenmäki and Mari Kiviniemi serving as prime ministers under president Tarja Halonen.
Yin and yang are universal aspects all things can be classified under, this includes diseases in general as well as the Eight Principles' first three couples. For example, cold is identified to be a yin aspect, while heat is attributed to yang. Since descriptions of patterns in terms of yin and yang lack complexity and clinical practicality, though, patterns are usually not labeled this way anymore. Exceptions are vacuity-cold and repletion-heat patterns, who are sometimes referred to as "yin patterns" and "yang patterns" respectively. Exterior (表; biǎo) refers to a disease manifesting in the superficial layers of the body – skin, hair, flesh, and meridians. It is characterized by aversion to cold and/or wind, headache, muscle ache, mild fever, a "floating" pulse, and a normal tongue appearance. Interior (里; lǐ) refers to disease manifestation in the zàng-fǔ, or (in a wider sense) to any disease that can not be counted as exterior. There are no generalized characteristic symptoms of interior patterns, since they'll be determined by the affected zàng or fǔ entity. Cold (寒; hán) is generally characterized by aversion to cold, absence of thirst, and a white tongue fur. More detailed characterization depends on whether cold is coupled with vacuity or repletion. Heat (热; rè) is characterized by an absence of aversion to cold, a red and painful throat, a dry tongue fur and a rapid and floating pulse if it falls together with an exterior pattern. In all other cases, symptoms depend on whether heat is coupled with vacuity or repletion.
The downregulation of ALAS1 lowers the levels of neurotoxic intermediates that cause AHP symptoms. Years of research have led to a greater understanding of siRNA therapies beyond those affecting the liver. As of 2019, Alnylam Pharmaceuticals was involved in therapies that may treat amyloidosis and CNS disorders like Huntington's disease and Alzheimer's disease. They have also partnered with Regeneron Pharmaceuticals to develop therapies for CNS, eye, and liver diseases. As of 2020, Onpattro and Givlaari were available for commercial application, and two siRNAs, lumasiran (ALN-GO1) and inclisiran, have been submitted for new drug application to the FDA. Several siRNAs are undergoing phase 3 clinical studies, and more candidates are in the early developmental stage. In 2020, Alnylam and Vir Pharmaceuticals announced a partnership and have started working on an RNAi therapy that would treat severe cases of COVID-19. Other companies that have had success in developing a pipeline of siRNA therapies include Dicerna Pharmaceuticals, partnered with Eli Lilly and Company, and Arrowhead Pharmaceuticals, partnered with Johnson and Johnson. Several other large pharmaceutical companies, such as Amgen and AstraZeneca, have also invested heavily in siRNA therapies, seeing potential success in this area of biological drugs.
Stage: as with bone sarcomas, tumors that have metastasized have a worse prognosis compared to tumors that have not metastasized. Grade: the AJCC recommends using a grading system called the French Federation of Cancer Centers Sarcoma Group (FNCLCC) Grade for soft-tissue sarcomas, with high-grade tumors having a worse prognosis compared to low-grade tumors. For GISTs, the key factor that affects prognosis is:
Sources: en.wikipedia.org
== Function == The protein encoded by this gene contains a leucine-rich repeat and a death domain. This protein has been shown to interact with other death domain proteins, such as Fas (TNFRSF6)-associated via death domain (FADD) and MAP-kinase activating death domain-containing protein (MADD), and thus may function as an adaptor protein in cell death-related signaling processes. The expression of the mouse counterpart of this gene has been found to be positively regulated by the tumor suppressor p53 and to induce cell apoptosis in response to DNA damage, which suggests a role for this gene as an effector of p53-dependent apoptosis. Three alternatively spliced transcript variants encoding distinct isoforms have been reported. Besides its pro-apoptotic function it may also be involved in DNA repair as part of a protein complex formed together with the catalytic subunit of DNA-PK (DNA-PKcs) and caspase 2. Signaling pathways involving PIDD-C have been associated with the activation of NF-κB and the promotion of cell survival. Following DNA damage, PIDD-C relocates to the nucleus, where it forms a complex with RIP1 and the NF-kappa-B inhibitor kinase subunit gamma (NEMO, or IKBKG), collectively referred to as the 'NEMO-PIDDosome.' PIDD1 is also essential for translesion DNA synthesis (TLS), which enables DNA elongation across lesions in response to UV exposure.
== Work == From 1946 through 1956 Ettre worked at pharmaceutical and chemical engineering firms in Hungary. In 1956 he was appointed to the position of head of the Industrial Department of the Hungarian Research Institute on Plastics in Budapest. He held the position of chemical engineer at Lurgi AG in Frankfurt am Main, West Germany, where he began to work with gas chromatography. In the United States, Ettre worked at the PerkinElmer Corporation from 1958 until his retirement in 1990; he held the positions of Application Engineer, Product Specialist, Chief Applications Chemist, and Senior Staff Scientist, and finally Senior Scientist. Ettre's major research area was chromatography. His activities covered a variety of fields including surface area studies, trace analysis, detector response, reaction gas chromatography, the retention index system, headspace gas chromatography, and in particular the theory and practice of open-tubular (capillary) column gas chromatography. After his retirement, he focused on the history and evolution of chromatography and its relationship to other scientific disciplines. The history and variations of Hungarian philately in the period 1900–1944 was one of his lesser-known activities, in which he authored several monographs published by the Society for Hungarian Philately.
Cave of Elijah is the name used for two grottoes on Mount Carmel, in Haifa, Israel, associated with Biblical prophet Elijah. The main shrine known as the "Cave of Elijah" is located on Haifa's Allenby Road, on Mount Carmel, approximately 40 m above sea level. For centuries, it has been a destination for Jewish, Christian, Muslim and Druze pilgrims. The Cave of Elijah in Allenby Road is divided into twos sections for praying, one for men and one for women; the cave is behind a velvet curtain. The Cave is also known as el-Khader in Arabic. The Druze regard it as holy, and many among them identify Elijah as "el-Khidr", the green prophet who symbolizes water and life. The cave has been considered by some as miracle-working. Sick people are said to be brought to the Cave in hope that they will be cured. A second grotto, also associated with Elijah, is located nearby, under the altar of the main church of the Stella Maris Monastery, also on Mount Carmel.
Sources: en.wikipedia.org
GHK denotes the unbound chain of three amino acids. GHK-Cu describes the form in which a copper(II) ion is held by that chain. The two are not interchangeable in solution, since charge, molecular weight, and reactivity differ.
The chain occurs in human plasma, saliva, and urine. Measured amounts are reported to fall with age. Copper binding by the sequence is treated as part of normal metal handling in tissue.
The bound copper(II) centre contributes to redox behaviour and to stability under physiological conditions. Free copper ions can participate in reactions that generate reactive species, while chelated metal is generally more controlled. The chain may also serve as a carrier for copper in experimental systems.
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.