copper tripeptide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-02-22. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C | Sealed, desiccated, protected from light |
| Common analytical method | Reversed-phase HPLC with UV detection | Used for purity and identity screening |
| Mass spectrometric signal | About 402 m/z | Corresponds to the intact one-to-one complex |
| Visible absorption | Broad band near 525-630 nm | Arises from the copper coordination sphere |
| Preferred solvent | Water or dilute buffer | Strong chelators such as EDTA are avoided |
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.
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.
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.
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== External links == Histology image: 42_04 at the University of Oklahoma Health Sciences Center Histology image: 14302loa – Histology Learning System at Boston University Histology at KUMC endo-/endo10 Anatomy Atlases – Microscopic Anatomy, plate 15.287
In FFF the display of detector signals as a function of time is called fractogram, in contrast to the chromatogram of column chromatography techniques. The fractogram can be converted to a distribution plot of one or several physical properties of the analyte using FFF theory and/or detector signals. This can be size, molar mass, charge, etc. Often these substances are particles initially suspended in a small volume of a liquid buffer and pushed along the FFF channel by the buffer. The varying velocities of a particular species of particles may be due to its size, its mass, and/or its distance from the walls of a channel with non-uniform flow-velocity. The presence of different species in a sample can thus be identified through detection of a common property at some distance down the long channel, and by the resulting fractogram indicating the presence of the various species by peaks, due to the different times of arrival characteristic of each species and its physical and chemical properties.
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July 1971: The association "Choisir la cause des femmes" is created — with philosopher Simone de Beauvoir and lawyer Gisèle Halimi — to demand the repeal of the 1920 law criminalizing abortion. January 3, 1972: Law on parentage. It opens the right for the mother to challenge, under certain conditions, the presumption of the husband's paternity. January 3, 1972: Law on the stay-at-home mother's allowance. April 24, 1972: Decree applying Article 4 of Law 67-1176 of December 28, 1967, on birth control and repealing Articles L. 648 and L. 649 of the Public Health Code. July 13, 1972: Law establishing the general status of military personnel; access to military careers is not subject to sex-based discrimination. August 16, 1972: Decree on the specific status of the corps of national police inspectors, in which women are allowed to apply. December 22, 1972: Law affirming the principle of equal pay between genders. January 2, 1973: Law on the Labor Code, which updates it and includes provisions on women's work. January 9, 1973: Law amending and supplementing the French Nationality Code and concerning certain provisions related to French nationality; it notably authorizes the transmission of nationality by the mother to her child, whether the child is "legitimate or illegitimate." March 23, 1973: Decree establishing the special status of female military corps.
Sources: en.wikipedia.org
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.
Mass spectrometry provides the mass of the intact complex and any fragments. Reversed-phase chromatography supplies a purity figure. Visible spectroscopy shows the broad copper absorption band.
Yes, a peptide assay does not reveal the metal-to-peptide ratio. Elemental analysis such as inductively coupled plasma emission quantifies the copper. The value is checked against the expected one-to-one proportion.
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.