01 / Reference identity
GHK vs the copper complex.
GHK is the free tripeptide Gly–His–Lys. GHK-Cu is that tripeptide coordinated with copper(II), also called prezatide copper (CAS 89030-95-5). PubChem keeps one record for GHK and two for the copper complex.
The two copper records differ by one hydrogen and a charge: one draws the complex as a cation, the other as neutral. Neither describes the salt form of a supplied lot, which follows its own record.
| Record | Formula, weight | PubChem CID |
|---|---|---|
| GHK, the free tripeptide (prezatide) | C14H24N6O4, 340.38 g/mol | 73587 |
| Prezatide copper (GHK-Cu) | C14H23CuN6O4+, 402.92 g/mol | 71587328 |
| Cu-GHK | C14H24CuN6O4, 403.92 g/mol | 378611 |
02 / Molecular architecture
A closer look at the chain.
GHK is a tripeptide. Cu indicates the copper complex, not a fourth amino-acid residue. The diagram below shows the peptide sequence only; it does not map the metal’s coordination geometry.
- Gly–His–Lys
- Copper(II) coordination
- Peptide–metal complex
- 1Gly
- 2His
- 3Lys
Reference information: [1][2][3][4]. Actual lot identity must be verified separately.
A peptide backbone and a coordinated metal.
The GHK part names three linked amino acids. The Cu part identifies copper associated with that peptide as a coordination complex. Copper is not another residue added to the end of the chain. A backbone diagram therefore needs a separate explanation of the metal-containing reference.
What a cultured-cell finding measures.
The cited fibroblast study examined collagen synthesis in its cell-culture system. That experimental endpoint is different from measuring the amount of copper or identifying the peptide in a sample. Biological measurements and chemical characterization provide different kinds of information and should be labeled accordingly.
Structure and research references: [1]
03 / Read the evidence
Research & analytical context.
Maquart and colleagues investigated collagen synthesis in cultured fibroblasts exposed to GHK-Cu. Their reported response was not simply a consequence of more cells. The finding belongs to that cell-culture system.
Read the references: [1][2][3][4].
The distinction that matters
Free GHK, a copper salt and GHK-Cu are different test materials. A copper-colored appearance does not independently confirm identity, purity or copper content.
04 / From reference to record
Know the lot, too.
A publication describes its own test material. Your lot’s certificate describes what was tested on that lot. Keep the compound name, batch number and reported methods together when reviewing a result.
Identity & composition
Check sequence or chemical form, terminal modifications, counterion and—where relevant—each blend component.
Analytical results
Read purity, content, sterility and endotoxin results as separate measurements. Only call a test passed when the actual report supports it.
Handling & storage notes
Lyophilized material: Store at −20°C; protect from light and moisture.
Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.
How to store lyophilized peptides05 / Reference questions
A few details, explained.
Can the blue appearance verify GHK-Cu?
Appearance is not an independent identity or content measurement. The color does not establish which copper-containing species are present, the peptide amount or the analytical purity of a lot.
Does Cu mean a fourth amino acid?
No. Cu is the chemical symbol for copper. GHK remains the three-residue peptide backbone, with metal coordination described separately from residue order.
Read alongside the references: [1]
06 / Continue reading
Go to the source.
Each source is labeled by its type. External sources are not Pioneer batch certificates.
- Maquart et al. · GHK-Cu and cultured fibroblasts (1988)Published research · Read source (opens a new tab)
- PubChem · Prezatide copper (GHK-Cu) record, CID 71587328Public record · Read source (opens a new tab)
- PubChem · Cu-GHK record, CID 378611Public record · Read source (opens a new tab)
- PubChem · GHK, the free tripeptide, CID 73587Public record · Read source (opens a new tab)