GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, usually written Gly-His-Lys, and it is also sold as copper tripeptide-1. The standard complex holds one copper ion per peptide: C14H22CuN6O4, 401.91 g/mol, CAS 89030-95-5. That is a different substance from the free peptide GHK (CAS 49557-75-7), so the exact form named on the certificate matters. Available as 50 mg and 100 mg vials, for laboratory research use only.
Ask for the analytical documentation of any lot.
HPLC is the method used to measure purity
Ask for the report for a specific lot through the contact page
Supplied for laboratory research use only
Mass spectrometry is the method used to confirm identity
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine. The peptide is glycine, histidine and lysine in that order, which is where the initials come from. The standard complex holds one copper ion per peptide, and Veracue supplies it for laboratory research only.
Ingredient suppliers list the complex as Copper Tripeptide-1, and older records call it prezatide copper. All three names point at the same chemistry.
| Product name | GHK-Cu (copper tripeptide) |
| Other names | Copper Tripeptide-1; prezatide copper; glycyl-L-histidyl-L-lysine copper(II) |
| Peptide sequence | Gly-His-Lys (G-H-K), three amino acids |
| Metal | Copper(II), one ion per peptide in the standard 1:1 complex |
| Neutral 1:1 complex formula | C14H22CuN6O4 |
| Molecular weight (neutral 1:1 complex) | 401.91 g/mol |
| Copper complex CAS | 89030-95-5 |
| Free peptide (GHK) CAS | 49557-75-7 |
| Form | Lyophilized powder |
| Research designation | Research Use Only |
Physical appearance, purity, lot results, molecular form and storage conditions are reported on each lot’s documentation and can be requested through the contact page.
Copper binds through nitrogen donors from the glycine terminus and the histidine side chain, and the peptide gives up amide protons as the metal locks in. That is why the complex is written with fewer hydrogens than the free peptide.
No. GHK is the free tripeptide, C14H24N6O4, 340.38 g/mol, CAS 49557-75-7, a white peptide solid. GHK-Cu is the copper complex, roughly 402 g/mol depending on how the form is written, CAS 89030-95-5, and copper gives it colour.
Plenty of sources use the two names as if they were one compound. Some published laboratory work used the free peptide rather than the complex, so a finding reported for one does not automatically apply to the other. If a vendor labels a product GHK-Cu but the identity result matches 340 g/mol, the material is the free peptide and the copper is either absent or unaccounted for.
At least five different numbers circulate. Most describe genuinely different species, and the table sets each representation against its formula so a catalogue value or a COA entry can be matched to the species it describes.
| Representation | Formula | MW (g/mol) | Where you will see it |
|---|---|---|---|
| Free tripeptide, no copper (GHK) | C14H24N6O4 | 340.38 | PubChem CID 73587; CAS 49557-75-7 |
| Neutral 1:1 Cu(II) complex, two protons displaced | C14H22CuN6O4 | 401.91 | CAS 89030-95-5; the value most research suppliers quote |
| 1:1 Cu complex written as a cation | C14H23CuN6O4+ | 402.92 | PubChem CID 71587328, titled Prezatide copper |
| 2:1 peptide to copper adduct | C28H48CuN12O8 | 744.31 | PubChem CID 133697840, confusingly titled GHK-Cu |
| Prezatide copper acetate, 2:1 diacetate salt | C32H52CuN12O12 | 860.39 | CAS 130120-57-9; DrugBank DBSALT002420 |
Two corrections are worth making plainly, because both circulate widely. First, a number of pages pair the formula C14H22CuN6O4 with a weight near 403.9 g/mol. That formula sums to 401.91. The 402.92 figure belongs to the cationic form PubChem draws, which carries one more hydrogen.
Second, the acetate form is often listed around 462 to 467 g/mol, as though it were a 1:1 complex with one acetate attached. The registered substance behind CAS 130120-57-9 is not that. DrugBank records it as two peptide units, one copper and two acetates, averaging 860.39 g/mol. Some suppliers do sell a 1:1 mono-acetate, which is a different material again.
For a research powder the practical question is narrow. Which species was synthesised, and which species did the identity test match against? A COA that reports a mass without naming the form leaves that unanswered.
In 1980 Pickart and colleagues proposed in a Nature paper that the peptide works largely by shuttling copper into cells. That copper-transport framing is still where most mechanistic work starts. It is a laboratory-model proposal about copper handling, and it says nothing about any particular product.
Typical contexts are cell-culture work, copper coordination chemistry and analytical method development. The material is offered for in vitro and laboratory research only.
Both are copper(II) complexes of a tripeptide ending in histidine and lysine. The only structural difference is the first residue: glycine in GHK-Cu, alanine in AHK-Cu. That single change gives them separate CAS numbers and separate ingredient names, with GHK-Cu called Copper Tripeptide-1 and AHK-Cu called Copper Tripeptide-3. The two are often mixed up on supplier pages, and findings from one should not be attributed to the other.
It reports molecular reference information and general research context. It cannot establish what is in a particular vial, and it does not show that concentrations used in culture medium correspond to any other amount or route. A purity figure does not establish sterility or biological activity either. Veracue does not provide dosing, administration or usage guidance of any kind.
A purity percentage answers one question out of six. A useful GHK-Cu COA should let you confirm what the material is, which form it is, how pure it is by a named method, how much peptide is actually in the vial, whether copper is present in the expected ratio, and that the report belongs to the lot in your hand.
Copper complexes make the identity question sharper than it is for ordinary peptides. Because the free peptide, the neutral complex, the cationic form and the acetate salt all carry different masses, an identity result is only interpretable if the report states which species it was matched against.
| COA element | What it tells you | What it does not establish |
|---|---|---|
| Lot or batch number | Links the report to a specific production lot | Anything about quality unless it matches the vial label |
| HPLC purity (%) | Share of detected signal in the main peak under stated conditions | Identity, net peptide content, sterility or biological activity |
| LC-MS or mass spectrometry | Whether an observed mass is consistent with the expected species | Purity, or how much material is present |
| Stated molecular form | Which of the GHK-Cu species the result refers to | Identity on its own; it must be backed by analytical data |
| Copper content | Whether copper is present at the expected ratio to peptide | Purity of the peptide portion |
| Net peptide content | How much of the vial mass is peptide rather than salt or water | Chromatographic purity |
| Appearance and colour | A weak consistency check, since the complex is coloured and the free peptide is not | Anything quantitative |
| Laboratory name and test date | Who tested the lot and when | Independence, unless the relationship is disclosed |
These two methods get quoted together so often that they start to read like one test. They are not, and they fail in different directions.
HPLC separates what is in the sample and reports how much of the detected signal sits under the main peak. It is a purity measure. It cannot tell you that the main peak is the molecule you wanted, because a clean chromatogram of the wrong compound still looks clean.
Mass spectrometry answers the identity question by measuring mass. It tells you whether the species present matches an expected mass, which is exactly what a copper complex needs, since the metal changes the number. It does not tell you what fraction of the vial that species represents.
| Method | What it measures | What it cannot answer |
|---|---|---|
| HPLC | Chromatographic purity under stated conditions; presence of related substances | Whether the main peak is the intended molecule; how much peptide is in the vial |
| LC-MS / MS | Whether an observed mass matches the expected species, including the copper-bound form | Purity; quantity; sterility |
| Neither method | Not applicable | Endotoxin status or suitability for any use in a living system |
Storage conditions follow the lot’s own documentation and label. Handle the material as a laboratory chemical with appropriate personal protective equipment. The certificate page explains how to see lot documentation.
Ask the Veracue team for the documentation that belongs to a specific lot, or browse the certificate library.
GHK-Cu supplied by Veracue is intended solely for laboratory research, scientific investigation and analytical characterization. It is not a drug, cosmetic, dietary supplement or food, and it must not be given to humans or animals. This page contains no dosing, administration or usage guidance of any kind. See the Medical Disclaimer and the Terms and Conditions for sitewide policies.
RESEARCH PEPTIDE
Snap8 is an eight-residue peptide, Ac-EEMQRRAD-NH2 (CAS 868844-74-0), and not the same as Argireline. Sold in 10 and 20 mg vials for research use only.
RESEARCH PEPTIDE
AHK-Cu has a different molecular weight for each form, from 354.41 to 452.40 g/mol, so check the form on your COA. 50 and 100 mg, research use only.
