glycyl-histidyl-lysine is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-09-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Identity and purity are established with a combination of chromatographic and spectroscopic techniques. Reversed-phase high-performance liquid chromatography separates the intact complex from peptide fragments and free copper, and the elution profile yields a purity estimate. Mass spectrometry gives the mass of the intact species and exposes degradation products. Ultraviolet-visible spectroscopy displays a broad absorption band in the visible region that is characteristic of the copper center. Nuclear magnetic resonance is less informative here, because the paramagnetic metal broadens signals and complicates spectral interpretation.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II) tripeptide complex | Contains glycyl-histidyl-lysine ligand |
| Peptide sequence | Gly-His-Lys | N-terminal glycine, C-terminal lysine |
| Molecular formula | C14H22CuN6O4 | Commonly cited for the 1:1 complex |
| Appearance | Blue to blue-violet solid | Color arises from copper d-d transitions |
| Solubility | Water-soluble | Also dissolves in some polar solvents |
Published work on GHK-Cu concentrates largely on cell culture systems rather than whole organisms. Frequently used endpoints include collagen synthesis, expression of matrix metalloproteinases, and migration of fibroblasts. Some reports describe antioxidant behavior, while others stress delivery of copper into cells. These mechanisms are proposed rather than demonstrated, and the relative weight of each pathway is unclear. Human trials are few and generally small, so laboratory findings should not be read as confirmed clinical results.
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.
Solid material is typically kept as a lyophilised powder in a sealed, light-protected container at minus 20 degrees Celsius, with desiccant where humidity is high. Working solutions are often prepared fresh, aliquoted and frozen to avoid repeated freeze-thaw cycles. Glassware and buffers are checked for trace metal contamination, since other transition metals can displace copper. Records of lot number, reconstitution date and storage temperature help trace unexpected colour changes. Blue colour itself is not a reliable purity test, because partly degraded solutions can remain visibly coloured.
Identity and purity are normally checked by reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry. The peptide absorbs in the ultraviolet region, and the copper complex also shows a broad visible absorption band that can be followed spectroscopically. Copper content is measured separately, for example by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy, because the peptide assay alone does not confirm how much metal is bound. Purity figures therefore need a stated basis: peptide peak area, copper content, or both.
Aqueous GHK-Cu solutions are less stable than the dry powder. Light, dissolved oxygen and elevated temperature all accelerate loss of the intact complex, and the main observable changes are fading of the blue colour and the appearance of peptide fragments. Acidic conditions protonate the histidine imidazole and weaken copper binding, while strongly alkaline conditions promote hydrolysis of the peptide backbone. Because several degradation routes operate at once, a single shelf-life figure does not describe all storage conditions.
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.
msConvert: A command line tool converting to/from various mass spectrometry formats. A GUI is also available for Windows users. ReAdW: The Institute for Systems Biology command line converter for Thermo RAW files, part of the TransProteomicPipeline. The latest update of this tool was made in September 2009. Users are now redirected by the TPP development team to use the msConvert software (see above). FileConverter: A command line tool that converts to/from various mass spectrometry formats, part of TOPP Converters for proprietary formats:
Berries are a type of simple fleshy fruit that issue from a single ovary. (The ovary itself may be compound, with several carpels.) The botanical term true berry includes grapes, currants, cucumbers, eggplants (aubergines), tomatoes, chili peppers, and bananas, but excludes certain fruits that are called "-berry" by culinary custom or by common usage of the term – such as strawberries and raspberries. Berries may be formed from one or more carpels (i.e., from the simple or compound ovary) from the same, single flower. Seeds typically are embedded in the fleshy interior of the ovary. Examples include:
=== Anti-hypoxant === Bemethyl has been shown to preserve both physical and mental capacity in high-altitude, low-oxygen environments, particularly by its effect in helping control excess serum levels of cholesterol and bilirubin, which are known to have negative effects especially during adjustment to high-altitude environments.
== Ecology == A giant orchid weighing two tons was one of the highlights in the 1851 exhibition at the Crystal Palace in London. Because of its enormous size, it is rarely cultivated as this species is usually too large to be accommodated in most greenhouses. Cultivated specimens of this species are always grown as terrestrials, as the plants grow as both an epiphyte and terrestrial in habitat.
Placing a wedge in the felling cut can prevent a sitback from pinching the saw. Freeing: Working a badly fallen tree that may have become trapped in other trees. Working out maximum tension locations to decide the safest way to release tension, and a winch may be needed in complicated situations. To avoid cutting straight through a tree in tension, one or two cuts at the tension point of sufficient depth to reduce tension may be necessary. After tension releases, cuts are made outside the bend. Limbing: Cutting the branches off the log. The operator must be able to properly reach the cut to avoid kickback. Bucking: Cross-cutting the felled log into sections. Setup is made to avoid binding the chainsaw within the changing log tensions and compressions. Safe bucking is started at the log high-side and then sections worked offside, toward the butt end. The offside log falls and allows for gravity to help prevent binds. The log's kerf movement while cutting can help to indicate binds. Additional equipment (lifts, bars, wedges, and winches) and special cutting techniques can help prevent binds. Binds: This is when the chainsaw is at risk or is stuck in the log compression. A log bound chainsaw is unsafe and must be carefully removed to prevent equipment damage. Top bind – The tension area on log bottom, compression on top. Bottom bind – The tension area on log top, compression on bottom. Side bind – Sideways pressure exerted on the log. End bind – Weight compresses the log's entire cross-section.
Sources: en.wikipedia.org
==== Phase transitions ==== At a pressure of one atmosphere (atm), ice melts or water freezes (solidifies) at 0 °C (32 °F) and water boils or vapor condenses at 100 °C (212 °F). However, even below the boiling point, water can change to vapor at its surface by evaporation (vaporization throughout the liquid is known as boiling). Sublimation and deposition also occur on surfaces. For example, frost is deposited on cold surfaces while snowflakes form by deposition on an aerosol particle or ice nucleus. In the process of freeze-drying, a food is frozen and then stored at low pressure so the ice on its surface sublimates. The melting and boiling points depend on pressure. A good approximation for the rate of change of the melting temperature with pressure is given by the Clausius–Clapeyron relation:
== June 30, 1915 (Wednesday) == Shabin-Karahisar uprising — Out of ammunition, the remaining men of the Armenian militia in the Giresun Province of Turkey engaged Ottoman troops in hand-to-hand combat. Ottoman soldiers defeated the militia and entered the fort the resistance had holed up in to massacre Armenian women, children and elderly inside. British destroyer HMS Lightning struck a mine in the Thames Estuary of England. She broke in two, the bow section sinking with the loss of fifteen of her crew. The stern section was towed to Sheerness, Kent where it was later scrapped. French commander Henri Gouraud was wounded at Gallipoli and replaced by his divisional commander, Maurice Bailloud. German submarine SM UC-2 struck a mine and sank in the North Sea. The Hay Gaol prison closed in Hay, New South Wales, Australia due to its small inmate population (it had only three prisoners). Born: Harry Weese, American architect, designer of the Washington Metro; in Evanston, Illinois, United States (d. 1998) Died: Preston Watson, 35, Scottish aviator, designer of aircraft that could be airborne under their own power; killed in a plane crash (b. 1880)
Humans exhibit a variety of abilities. This includes an ability of emotional Hedonic Adaptation, an idea suggesting that beauty, fame and money do not generally have lasting effects on happiness (this effect has also been called the Hedonic treadmill). In this vein, some research has suggested that only recent events, meaning those that occurred within the last 3 months, affect happiness levels. The tendency to adapt, and therefore return to an earlier level of happiness, is illustrated by studies showing lottery winners are no happier in the years after they've won. Other studies have shown paraplegics are nearly as happy as control groups that are not paralyzed, after equally few years. Daniel Kahneman explains: "they are not paraplegic full time... It has to do with allocation of attention". Thus, contrary to our impact biases, lotteries and paraplegia do not change experiences to as great a degree as we would believe. However, in a newer study (2007), winning a medium-sized lottery prize had a lasting mental wellbeing effect of 1.4 GHQ points on Britons even two years after the event. Moreover, adaptation can be a very slow and incomplete process. Distracting life changes such as the death of a spouse or losing one's job can show measurable changes in happiness levels for several years. Even the "adapted" paraplegics mentioned above did ultimately report lower levels of pleasure (again, they were happier than one would expect, but not fully adapted).
3 H2N-CO-NH2 → [C(O)NH]3 + 3 NH3 CYA crystallizes from water as the dihydrate. Cyanuric acid can be produced by hydrolysis of crude or waste melamine followed by crystallization. Acid waste streams from plants producing these materials contain cyanuric acid and on occasion, dissolved amino-substituted triazines, namely, ammeline, ammelide, and melamine. In one method, an ammonium sulfate solution is heated to the "boil" and treated with a stoichiometric amount of melamine, by which means the cyanuric acid present precipitates as melamine-cyanuric acid complex. The various waste streams containing cyanuric acid and amino-substituted triazines may be combined for disposal, and during upset conditions undissolved cyanuric acid may be present in the waste streams.
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Sources: en.wikipedia.org
GHK is the free tripeptide, while GHK-Cu includes a bound copper(II) ion. The copper complex is the form most often studied for skin and wound-related activity. The two names are sometimes used interchangeably in product labeling, but they refer to distinct chemical species.
Yes, it is found in human plasma, saliva, and urine. Its concentration in plasma tends to decrease with age. This natural presence is one reason researchers have investigated its role in tissue maintenance.
No, GHK-Cu is not an approved drug in major markets. It is widely used as a cosmetic ingredient, where it is listed under names such as copper tripeptide-1. Any therapeutic claims would require separate regulatory review.
Lyophilized material is normally held at about minus twenty degrees Celsius in a sealed, desiccated vial. Dissolved samples are less durable and are prepared fresh. Repeated freeze-thaw cycles are avoided.