Everything below concerns reversed-phase HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, a short sequence of three amino acids. The peptide was first isolated from human plasma in 1973 during research on factors that influence tissue repair in liver. Its ability to bind copper ions became a central point of interest because the metal changes the peptide's chemistry and its behaviour in laboratory systems. Today the compound appears in cosmetic formulations, cell-culture studies, and biochemistry literature under several names.
The peptide sequence places a histidine in the middle, and this residue dominates metal binding. Copper(II) coordinates through the imidazole nitrogen of histidine and the terminal amino group, forming a stable chelate ring system. Loss of the copper ion leaves the free tripeptide, which has different solubility and reactivity. This structural detail matters because assays that measure only the peptide backbone can miss whether copper is still bound to it.
Several names circulate for the same material, which complicates literature searches. Cosmetic ingredient lists often use copper tripeptide-1, while older biochemistry papers use glycyl-L-histidyl-lysine or its abbreviation GHK. The copper complex is sometimes written as GHK-Cu(II) to make the oxidation state explicit. Terminology is not fully standardized, so matching a compound across sources requires attention to the exact sequence, the counterion, and the stated copper content. Reviews that compare studies must account for these naming differences before drawing conclusions.
Routine handling calls for minimizing freeze-thaw cycles and preparing solutions shortly before use. Glass or inert plastic containers reduce adsorption and metal leaching. Working stocks are often kept at 2–8 °C for short periods, while long-term reference material stays at −20 °C or below. Light protection is prudent because prolonged exposure may accelerate oxidation of the peptide. Documentation of lot number, concentration, and preparation date supports reproducibility in laboratory work.
Analytical verification typically combines reversed-phase high-performance liquid chromatography with ultraviolet-visible detection. The copper complex absorbs visible light near 600–630 nm, giving a characteristic blue signal. Mass spectrometry confirms molecular mass and can detect free peptide or mismatched copper stoichiometry. Copper content is often measured independently by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy. Purity, counterion identity, and residual solvents are additional quality-control parameters that methods may address.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Gly-His-Lys | Three amino acids, histidine in the middle |
| Complex formula | C14H22CuN6O4 | One copper(II) ion per peptide |
| Molar mass (complex) | approx. 402.9 g/mol | Depends on counterion and hydration state |
| Appearance | Blue to blue-violet solid | Colour arises from copper coordination |
| Common synonyms | Copper tripeptide-1, GHK-Cu | Naming varies between disciplines |
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.
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.
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.
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.
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.
=== Vorhand === Bei der Vorhand (engl. forehand) wird der Ball auf der Seite der Schlaghand (bei einem Rechtshänder also rechts, bei einem Linkshänder links) gespielt. In der Regel wird der Vorhandschlag mit einer Ausholbewegung eingeleitet und der Ball idealerweise etwa hüfthoch seitlich vor dem Körper getroffen. Früher war auch der sogenannte Westerngriff verbreitet, bei dem der Ball weit vor dem Körper getroffen wird. In der Regel wird die Vorhand einhändig gespielt und auch so gelehrt. Zu den wenigen Spielern, welche die Vorhand beidhändig spielen, gehörten Monica Seles und Fabrice Santoro. Von Carlos Moyá heißt es, er spielte die beste Vorhand im Herrentennis. Später trainierte er den Spieler mit der „zweitbesten“ Vorhand: Rafael Nadal.
=== Rückhand === Bei der Rückhand (engl. backhand) wird der Ball auf der der Schlaghand gegenüberliegenden Seite (bei einem Rechtshänder also links, Linkshänder rechts) geschlagen. Ein Rückhandschlag kann sowohl einhändig als auch beidhändig ausgeführt werden. Die beidhändige Rückhand ist erst in den 1970er Jahren bekannt geworden. Anfängern wird diese häufig empfohlen, da die Durchführung einfacher zu erlernen ist als die einhändige Rückhand. Mittlerweile ist die beidhändige Rückhand auch unter Profispielern vorherrschend. Ausnahme ist der Rückhand-Slice, der meist einhändig geschlagen wird. Die beste zweihändige Rückhand soll Novak Đoković spielen, die beste einhändige Rückhand Stan Wawrinka.
Der Aufschlag (engl. Service) leitet den Ballwechsel ein. Aus einer Position hinter der Grundlinie muss der Ball in das gegenüberliegende Aufschlagfeld geschlagen werden. Die Linien gehören zum Aufschlagfeld. Ein Überschreiten oder die Berührung der Grundlinie vor dem Treffen des Balls ist regelwidrig. Der Aufschlag beginnt mit einer Konzentrationsphase. Normalerweise lässt man den Tennisball ein paar Mal aufspringen, um ihn dann für den Aufschlag einzusetzen. Jeder Aufschläger hat zwei Versuche; nach erfolglosem zweiten Versuch gehört der Punkt dem Gegner. Nach einem Spiel wechselt das Aufschlagrecht. Der Aufschlag kann, wie bei einem Grundlinienschlag, je nach taktischer Auslegung mit unterschiedlicher Rotation gespielt werden. Man unterscheidet dabei zwischen einem flachen und schnellen Aufschlag mit nur geringem Vorwärtsdrall, einem Topspin- und einem Sliceaufschlag. Den günstigsten Schlagwinkel und dadurch höchste Ballgeschwindigkeiten erreicht man, wenn der Ball über Kopfhöhe geworfen und am höchstmöglichen Punkt getroffen wird. Im modernen Herrentennis werden mit dem ersten Aufschlag oft Geschwindigkeiten über 200 km/h erreicht. Aufschlaggeschwindigkeiten beim Tennis werden mittels Radargeräten gemessen. Der Weltrekord wird vom Australier Sam Groth gehalten und beträgt 263 km/h. John Isner schlug 14.470 Asse in insgesamt 772 Matches und hält damit den Rekord. Er profitierte dabei auch von seiner Körpergröße von 2,08 Meter.
Während des Schlages kann der Spieler die Eigenrotation des Balles beeinflussen, die wiederum die Flugkurve und das Absprungverhalten des Balles bestimmt. Man unterscheidet hierbei Drive (kaum Eigenrotation), Topspin (Rotation in Flugrichtung) und Slice (Rotation entgegen der Flugrichtung).
Sources: de.wikipedia.org
The peptide is glycyl-L-histidyl-L-lysine, a three-amino-acid sequence commonly abbreviated GHK. It binds a single copper(II) ion under typical laboratory conditions. The free peptide and the copper complex are separate chemical species with different properties.
The sequence was identified in human plasma in 1973. Early work examined its presence in blood and its proposed role in tissue repair. The copper-binding property was characterized afterward and became the focus of much later research.
The tripeptide has been measured in human plasma and other biological fluids. Whether it circulates mainly as the copper complex or as the free peptide remains an open question. Natural concentrations are low and difficult to measure reliably.
Dry powder is typically stored frozen at −20 °C or lower, protected from moisture and light. Short-term working amounts may be kept refrigerated. Avoiding repeated temperature changes helps preserve the material.