RP-HPLC 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.
Last reviewed on 2026-03-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
The tripeptide was first isolated from a human plasma filtrate in 1973 during studies of tissue repair factors. Later work detected the free peptide and its copper complex in saliva, urine, and wound fluid, suggesting a natural role in tissue remodeling. Plasma concentrations reported in early literature decline with age, a pattern often cited in discussions of skin aging. Whether these endogenous levels are directly functional or largely incidental remains an open question. The peptide sequence is conserved across mammalian species.
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.
Solid GHK-Cu appears as a blue to blue-violet powder, and the colour is a direct consequence of copper coordination. The complex dissolves readily in water and in many polar solvents, while the free peptide behaves differently. Solubility in nonpolar media is low, which limits its use in oil-based systems. Solutions are typically prepared fresh because the dissolved form is more exposed to hydrolysis and to loss of the metal ion than the dry powder. Working concentrations are usually low, and preparation notes often specify the solvent and the order of addition.
Dry material is typically held at low temperature, often around minus twenty degrees Celsius, and protected from moisture and light. Copper complexes can release their metal ion under acidic conditions or in the presence of competing chelators. Hydrolysis of the peptide backbone is a slower but real pathway, and the histidine residue is susceptible to oxidation over long periods. Stability statements therefore depend on formulation, pH, and container, and they should be read as conditional rather than absolute.
Identity and purity are usually assessed with reversed-phase high-performance liquid chromatography, often paired with mass spectrometry. Copper content is measured separately by techniques such as inductively coupled plasma mass spectrometry or atomic absorption. Amino acid analysis confirms the peptide sequence after hydrolysis. Because the metal and the peptide can be quantified independently, a complete certificate of analysis normally reports both values rather than a single purity figure. This separation of measurements is important when comparing suppliers.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H24N6O4 | Free tripeptide, without copper |
| Molecular weight | About 340 g/mol | Peptide portion only |
| Appearance | Blue to violet powder | Color from copper coordination |
| Solubility | Soluble in water | pH influences dissolution |
| Common synonyms | Copper tripeptide-1, Cu-GHK | Seen on ingredient labels |
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.
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.
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.
== Typen und Vorkommen == β-Glucane wurden erstmals in Flechten entdeckt und kurz darauf in Gerste. β-Glucane sind ein natürlicher Bestandteil der Zellwände von Bakterien, Pilzen und Pflanzen. In Protisten können β-Glucane ungebunden in der Form von Paramylonen vorkommen. Die verschiedenen Arten von β-Glucanen sind durch unterschiedliche Bindungen der Glucose-Moleküle charakterisiert, außerdem durch verschiedene Verzweigungsgrade und unterschiedliches Molekulargewicht, wodurch Löslichkeit und andere physiologische Eigenschaften wesentlich beeinflusst werden. Beta-glycosidische Bindungen können nicht unmittelbar von den meisten Tieren verstoffwechselt werden, da sie keine eigenen Verdauungsenzyme zur Spaltung der β-glycosidischen Bindung besitzen (allerdings besitzen sie dazu befähigte Enzyme außerhalb ihrer Verdauung, beispielsweise als Lysozym). Innerhalb ihrer Verdauung sind Mikroorganismen ihres Mikrobioms am Abbau von glyosidischen Bindungen engagiert. Wegen der geringen Abbaurate zählen β-Glucane zu den Ballaststoffen. β-Glucane aus Getreide bestehen aus β-1,3- und β-1,4-verknüpften D-Glucopyranose-Einheiten. Hefe-β-Glucane sind β-1,3- und β-1,6-glycosidisch verknüpft. Die β-Glucane in Gerste sind zu 27 % in den Wänden der Aleuronzellen und zu 73 % in den Zellwänden des Endosperms vorhanden, während sich die β-Glucane des Hafers in der Subaleuronschicht konzentrieren. Die Brotgetreide Weizen (0,8 %) und Roggen (2,3 %) enthalten nur geringe Mengen β-Glucan.
Andere Quellen sind einige Algenarten, Protisten wie Euglena gracilis sowie verschiedene Arten von Pilzen wie Reishi (Glänzender Lackporling, Ganoderma lucidum), Ganoderma applanatum, Shiitake, Chaga (Schiefer Schillerporling) und Maitake (Gemeiner Klapperschwamm). Für Nahrungsergänzungsmittel und Lebensmittel werden β-1,3-D-Glucane zum Beispiel aus der Zellwand der Backhefe Saccharomyces cerevisiae gewonnen oder sind natürlicher Bestandteil des Protisten Euglena gracilis. Die so gewonnenen β(1,3)D-Glucane sind oft unlöslich. β-1,3- und β-1,4-Glucane werden auch aus Haferkleie sowie aus dem Korninneren von Gerste extrahiert. Von β-Glucan-Gersten dienen die Körner auch in Form von Gersten-Flocken und Gerstenmehl für Brote und Backwaren als β-Glucan-Lieferant. Beim Brauen von Bier fallen β-Glucane als unerwünschte Nebenprodukte an, da sie ein Indikator für vermindertes Mälzen sind und die Viskosität der Bierwürze erhöhen.
== Eigenschaften == Je nach der Form des β-Glucan ergeben sich unterschiedliche Eigenschaften. 1,3-gebundene β-Glucane sind Ballaststoffe, welche nicht verdaut werden können, aber im Darm vom Körper als fremd erkannt werden. Beta-Glucane mit β-(1→3) und β-(1→6)-Verzweigung binden an die Rezeptoren Dectin-1, Komplementrezeptor 3 (CR3) und Toll-like Rezeptoren (TLR). Einige Studien lassen darauf schließen, dass Beta-Glucane hierdurch immunmodulatorische Eigenschaften haben. Eine tägliche Aufnahme von 3 g β-Glucan aus Gerste (1,3 u. 1,4) reduziert den LDL-Spiegel und kann das Risiko für Herz-Kreislauf-Erkrankungen senken. Der genaue Stoffwechselprozess für diesen Effekt ist noch nicht geklärt. Auch fördern β-Glucane das Wachstum gesunder Darmbakterien, wie dem Lactobazillus, in der Art eines Prebiotikums, also als „Futter“ für die Bakterien. Lösliche β-Glucane finden als Ballaststoffe in verschiedenen medizinisch verwendeten Nahrungsergänzungsmitteln, in kosmetischen Produkten Anwendung und als Texturierungsmittel in Lebensmitteln Verwendung.
Sources: de.wikipedia.org
=== Durchblutung === β-Glucane aus Hafer und Gerste erzeugen eine Vielzahl von physiologischen Wirkungen, die sich teilweise positiv auf die Gesundheit auswirken. β-Glucane aus Gerste und Hafer wurden bei Probanden mit Hypercholesterinämie im Hinblick auf ihre Auswirkungen auf die Senkung des Herzinfarkt-Risikos untersucht. β-1,3/1,4-Glucan senkt vermutlich einen erhöhten Cholesterinspiegel und vermindert damit einen wichtigen Risikofaktor für Gefäßerkrankungen, wie Arteriosklerose, Bluthochdruck, Herzinfarkt und Schlaganfall.
Sources: de.wikipedia.org
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.
The peptide and its copper form have been detected in human plasma, saliva, and urine. Early reports describe levels that fall with age. The functional meaning of these pools is still debated.
Chromatographic separation gives peptide purity, often reported as a percentage. Copper content is checked by a separate elemental method. Moisture and counter-ions may be reported as well.
The colour comes from electronic transitions in the coordinated copper(II) ion. Ligand field effects absorb part of the visible spectrum. A colourless or greenish sample may indicate degraded material.