GHK-Cu copper peptide: chemistry, identifiers and what to check
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GHK-Cu is a complex of the tripeptide glycyl-L-histidyl-L-lysine (Gly-His-Lys, or GHK) with a copper(II) ion. It is also known by the ingredient name copper tripeptide-1. This guide covers its identifiers, why the material is blue, how it differs from related compounds, and what to look for in the documentation.
GHK-Cu at a glance
| Compound | GHK-Cu (copper tripeptide-1) |
|---|---|
| Peptide | Glycyl-L-histidyl-L-lysine (Gly-His-Lys) |
| Metal ion | Copper(II) |
| CAS number (copper complex) | 89030-95-5 |
| CAS number (GHK peptide alone) | 49557-75-7 |
| GHK molecular formula | C14H24N6O4 |
| GHK molecular weight | Approximately 340.4 g/mol (the copper complex is heavier) |
| Supplied form | Lyophilised powder, 50mg and 100mg vials |
What is the difference between GHK and GHK-Cu?
GHK is the tripeptide on its own. GHK-Cu is that same tripeptide bound to a copper(II) ion. The peptide holds the copper through nitrogen atoms on its glycine and histidine residues, forming a stable coordination complex. GHK was first described in the scientific literature in 1973.
The two have different CAS numbers and different masses, so a listing and its documentation should state clearly which one is supplied. Ascend Research lists the copper complex.
Why is GHK-Cu blue?
Copper(II) complexes absorb light in the visible range, which gives GHK-Cu a characteristic blue colour as a powder and in solution. The free GHK peptide without copper is white. Colour is therefore a quick visual cue, though it is not a substitute for analytical documentation.
How does GHK-Cu differ from AHK-Cu?
AHK-Cu is a closely related copper tripeptide in which the first residue is alanine instead of glycine (Ala-His-Lys). It is a different compound with its own identity, and it is listed separately as AHK-Cu 100mg.
Which listings contain GHK-Cu?
| Listing | GHK-Cu quantity and format |
|---|---|
| GHK-Cu | 50mg or 100mg, single-compound vial |
| Glow Blend 70mg | 50mg, premixed with BPC-157 and TB-500 |
| Klow Blend 80mg | 50mg, premixed with BPC-157, TB-500 and KPV |
| [3V] KPV + BPC-157 + GHK-Cu Research Set | 50mg, in its own vial |
| [3V] GHK-Cu + AHK-Cu + Snap-8 Research Set | 100mg, in its own vial |
What should the documentation show?
- Which form was tested: the copper complex, not the free peptide.
- The batch number, matching the vial label.
- An HPLC purity figure and an identity result.
- The appearance of the material.
Batch documents are on the COAs page. See also how to read a peptide certificate of analysis.
Frequently asked questions
What does GHK-Cu stand for?
GHK is the one-letter code for the tripeptide glycine-histidine-lysine, and Cu is the chemical symbol for copper. GHK-Cu is the copper(II) complex of that tripeptide.
What is the CAS number for GHK-Cu?
The copper complex is listed under CAS 89030-95-5. The GHK peptide without copper has the separate CAS number 49557-75-7.
Why is GHK-Cu blue?
The copper(II) ion in the complex absorbs visible light, which gives the material a blue colour. GHK without copper is white.
Is copper tripeptide-1 the same as GHK-Cu?
Yes. Copper tripeptide-1 is an ingredient name for the GHK copper complex.
What is the difference between GHK-Cu and AHK-Cu?
They are different compounds. GHK-Cu is based on Gly-His-Lys, while AHK-Cu is based on Ala-His-Lys.
All Ascend Research products are sold strictly for laboratory research use only. They are not for human or animal use, and nothing in this article is medical advice.
The Ascend Research team
