Quick answer: GHK-Cu is a copper complex of the tripeptide Gly-His-Lys. Matrixyl 3000 is a trade-name blend of two palmitoylated peptides with no copper. They overlap in sequence but differ in metal content, lipid chain, solubility and evidence base. A certificate for GHK-Cu should confirm the copper complex, not just purity. All materials are for laboratory research use only.
Two names that look alike but are different materials
GHK-Cu and Matrixyl 3000 are often mentioned together in skin-biology and cell-culture discussions, because both are built around the same three amino acids. That overlap leads many readers to assume one is a branded version of the other. It is not. GHK-Cu is a copper complex of a naturally occurring tripeptide. Matrixyl 3000 is a trade name for a cosmetic-ingredient blend of two palmitoylated peptides, neither of which contains copper.
This guide compares them on chemistry, origin, how each is described in the literature, and what a buyer should check on a certificate. It is background for laboratory research use only. Nothing here describes an effect or a use in people or animals. For single-compound background, see the GHK-Cu research overview and the plain-language GHK-Cu explainer.
What GHK-Cu is
GHK is the tripeptide glycyl-L-histidyl-L-lysine. It was first isolated from human plasma in the early 1970s by Loren Pickart, who noticed that it forms a tight complex with copper(II). GHK-Cu is that complex: one copper ion held by the peptide through the histidine side chain, the N-terminal amine and backbone nitrogens. The free peptide without copper (GHK) is a separate species with different handling and a different appearance as a powder.
The GHK-Cu literature is broad. A 2018 review by Pickart and Margolina summarizes reported effects on gene expression in cell-based and gene-database work, and it is the usual starting point for anyone reading about the topic. As with any review written by the research group that studies a compound, readers should read its conclusions as one view and check the underlying primary papers. GHK-Cu is a small, hydrophilic molecule, and in aqueous solution it has a characteristic blue tint from the copper.
Side-by-side comparison
| Feature | GHK-Cu | Matrixyl 3000 |
|---|---|---|
| What it is | Copper(II) complex of one tripeptide | Trade-name blend of two palmitoylated peptides |
| Peptide sequence(s) | Gly-His-Lys | Palmitoyl-Gly-His-Lys and palmitoyl-Gly-Gln-Pro-Arg |
| Contains copper | Yes | No |
| Lipid group | None | Palmitic acid on each peptide |
| Typical solubility | Water-soluble | Poorly soluble in plain water |
| Single defined species | Yes | No, a mixture in a carrier |
| Main literature | Decades of cell and gene-expression papers | Smaller, mostly industry cosmetic-science work |
| Key identity check | Mass of the copper complex | Each component named and identified |
| Listed by V8 | Yes, for research use only | No |
What Matrixyl 3000 is
Matrixyl 3000 is a trade name, owned by the ingredient supplier that markets it, for a blend of two lipidated peptides. The first is palmitoyl tripeptide-1, which is the GHK sequence with a palmitic acid chain attached at the N-terminus. The second is palmitoyl tetrapeptide-7, a four-residue sequence (Gly-Gln-Pro-Arg) also carrying a palmitoyl group. In the marketed ingredient the two are supplied together in a carrier, and the name "3000" refers to the product generation, not to a concentration.
The palmitoyl group makes the peptides far more lipophilic than GHK-Cu. That is the whole point of the design: a fatty acid tail is intended to help a small peptide associate with lipid-rich membranes in skin-model experiments. The background on palmitoylated peptides in cosmetic science is laid out in the 2000 paper by Lintner and Peschard in the reference list. Note that this literature is largely from the ingredient industry, and much of it concerns finished formulations, not purified single peptides in cell-free assays.
One consequence is easy to overlook: Matrixyl 3000 is a mixture sold as a cosmetic raw material. It is not a single research peptide with a single sequence, and V8 does not list it. The comparison below is for researchers who encounter both names in the literature and want to read them correctly.
Side by side: chemistry and handling
The most important difference is copper. GHK-Cu carries a metal ion that is central to how it is described and measured. Matrixyl's two peptides carry no metal; they carry a fatty acid. That has practical results. GHK-Cu dissolves readily in water, while palmitoylated peptides are poorly soluble in plain aqueous buffers and are usually handled in a solvent system suited to lipids.
The second difference is composition. A vial of GHK-Cu should contain one defined species. A Matrixyl-type material contains at least two peptides and often a carrier, so a purity percentage for it means something different. A buyer reading a certificate for a blend should expect the report to name each component and its identity separately.
The third difference is the evidence base. GHK-Cu has decades of in vitro and gene-expression papers behind it. The palmitoylated peptides have a smaller literature, much of it from industry-sponsored cell culture and formulation studies. Neither has a body of evidence that supports claims about people, and this guide makes none.
Why a skin cell culture design might name both
Researchers working with fibroblast or keratinocyte cultures sometimes include a copper peptide and a palmitoylated peptide in the same panel to separate the contribution of the copper complex from that of a lipidated matrikine fragment. For that to work, each reagent must be what its label says. A palmitoylated peptide mislabeled as GHK, or a GHK sample that has lost its copper, will undermine the comparison without anything looking wrong on the bench.
A related question is how GHK-Cu compares with other copper-binding peptides, which is covered in GHK-Cu vs. other copper peptides. Sourcing and certificate expectations are in where to buy GHK-Cu.
What a certificate should show
For GHK-Cu, the purity percentage by HPLC is the starting point, but the copper is the thing most likely to be missing from the report. Ask whether the report states that the material is the copper complex and whether the copper content or the expected mass of the complex is shown. A GHK sample without copper and a GHK-Cu sample can look similar on a basic purity trace if the method does not account for the metal.
Also check the lot identifier, the test date and the compound name. Buyers working with cells should look for an endotoxin result and a sterility statement. General reading: understanding HPLC purity, how to read a COA and GHK-Cu purity testing.
V8 Peptides publishes certificates for only some products. Where one exists, it reports HPLC purity and identity, endotoxin and PCR sterility. This article describes general buyer practice and is not a statement about any particular lot. The V8 listing is at GHK-Cu copper peptide, for laboratory research use only.
Storage and record keeping
Keep sealed GHK-Cu powder cold, dry and away from light, and write down the date each vial is opened. Copper-containing solutions can shift over time, so record the preparation date for anything that is made up. This guide does not give volumes or concentrations, because those belong in a lab's own validated protocol.
For every vial in the notebook, record the exact compound name, lot, supplier, certificate date and storage conditions. If a design uses both a copper peptide and a palmitoylated peptide, label them clearly and keep their certificates together.
Frequently asked questions
Is Matrixyl 3000 a form of GHK-Cu?
No. It is a trade-name blend of palmitoylated peptides with no copper. One of them uses the GHK sequence, but it is a different molecule from the copper complex.
What is in Matrixyl 3000?
Per the supplier descriptions, palmitoyl tripeptide-1 and palmitoyl tetrapeptide-7 in a carrier. Check the primary documents, since compositions can vary by product.
What does the palmitoyl group do chemically?
It adds a fatty acid tail, which makes the peptide more lipophilic and less soluble in plain water.
Does GHK-Cu always contain copper?
The complex does. Plain GHK is the copper-free peptide, and the two should not be confused on a label.
Can HPLC purity confirm the copper is present?
Not by itself. The report should state that the material is the copper complex and show a mass or copper measurement.
Where does GHK come from?
It was isolated from human plasma in the early 1970s and found to bind copper(II).
Is the evidence for both the same size?
No. GHK-Cu has a much larger research literature than the palmitoylated peptides, and neither supports claims about people.
Does V8 sell Matrixyl 3000?
No. V8 lists GHK-Cu for laboratory research use only.
Does this article describe a use in people?
No. It summarizes chemistry and published laboratory work. Nothing sold here is for human or animal consumption.
What should I record for each vial?
The exact compound name, lot identifier, certificate date, supplier, storage conditions and the date the vial was opened.
References
- Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987.
- Lintner K, Peschard O. Biologically active peptides: from a laboratory bench curiosity to a functional skin care product. Int J Cosmet Sci. 2000;22(3):207-218.