If you plan to buy GHK-Cu as a research material, judge the supplier by a batch-specific certificate of analysis: HPLC purity, a mass-spectrometry result showing the copper complex near m/z 402.1, a copper-content or copper-to-peptide figure, and CAS 89030-95-5 matched to the lot. This guide covers what to check when sourcing GHK-Cu for in vitro work, where the metal and the peptide both have to be right.
What should a GHK-Cu certificate of analysis show?
| COA item | What to look for |
|---|---|
| Lot number and date | Matches the vial you receive, with a test date |
| HPLC purity | A chromatogram with one dominant peak and a stated percent purity |
| Mass spectrometry | Complex ion near m/z 402.11 with the copper partner near 404.11; free GHK would appear at 341.19 |
| Identifiers | GHK-Cu, CAS 89030-95-5, C14H23CuN6O4+, 402.92 g/mol, all belonging to the same species |
| Copper content | An elemental result (for example ICP-OES or ICP-MS) or a stated copper-to-peptide ratio near 1:1 |
| Appearance | Blue lyophilized powder |
| Net content and endotoxin | Net peptide content if reported, and an endotoxin result for cell-based work |
Why does copper content matter on a copper-peptide COA?
For a plain peptide, purity and identity are the core questions. For GHK-Cu, the metal is part of the compound, so a high peptide purity says nothing about whether copper is present at the expected ratio. The bare 1:1 cation is about 15.8% copper by mass (63.55 divided by 402.92); counter-ions and water in a lyophilized lot lower that figure, and a 2:1 peptide-to-copper species would sit near 8.6%. If your assay depends on the copper-to-peptide ratio, confirm that the certificate reports it, ask the supplier, or measure copper in-house. The difference between the metal-free and metal-bound forms is explained in GHK vs GHK-Cu.
How should the appearance and mass spectrum be read?
GHK-Cu is a deep blue lyophilized powder because of the copper(II) d-d absorption. A white powder suggests little or no copper, and an unusual green or brown tint suggests a different species or degradation. Color is a quick screen, not proof. Mass spectrometry carries the identity: the copper isotope doublet near 402.11 and 404.11 confirms the complex, whereas a peak only at 341.19 points to free peptide, although acidic conditions can strip copper in the source. For a line-by-line walkthrough of any certificate, see reading a certificate of analysis.
What are the red flags when you buy a copper peptide?
- A generic COA with no lot number or date.
- A purity figure with no chromatogram.
- Copper formula paired with the 340 g/mol free-peptide mass, or a CAS number that does not match.
- No mass-spectrometry data, or no way to tell complex from free peptide.
- A white powder sold as a copper complex.
- Marketing that implies human or animal use, which a genuine research-use-only supplier does not make.
Where can you source GHK-Cu as a research material?
Happy Peptides supplies GHK-Cu (CAS 89030-95-5, about 99% by HPLC) as a lyophilized research material in 50 mg and 100 mg vials, for in vitro use only. Batch reports listed on the product page cover identity, purity, net content and endotoxin. Before ordering, review the naming and identifiers in the GHK-Cu name-variants guide.
Find a COA: GHK-Cu batch reports are listed in our certificate of analysis library, searchable by batch number.
Related research guides
- AHK-Cu vs GHK-Cu: two copper-binding tripeptides compared
- Endotoxin testing for research peptides
- A researcher's guide to GHK-Cu
Research-use note
All materials discussed are supplied for in vitro laboratory research use only, and are not for human or animal use.
