GHK-Cu 50mg

What GHK-Cu is

GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (Gly-His-Lys). The metal is held by three nitrogens from the peptide: the free N-terminal amine of glycine, the deprotonated amide nitrogen between glycine and histidine, and a nitrogen of the histidine imidazole ring. The complex is sold under names such as copper tripeptide-1 and copper peptide, which are used loosely, so the CAS number is the field to match when comparing listings.

The free tripeptide, GHK, is a separate registry entry (CAS 49557-75-7, about 340.4 g/mol) and a different substance. The complex is blue because of d-d electronic transitions of the bound copper(II), while the free peptide is essentially colorless, which makes color a quick first-look signal that the complexed form is present. Copper accounts for roughly 16% of the complex by mass.

GHK-Cu 50mg specification

How GHK-Cu is analyzed

Small and very polar, GHK-Cu elutes early on a C18 column, so keeping it clear of the void region and of early-eluting impurities depends on a low starting organic fraction. The tripeptide has no tryptophan, tyrosine or phenylalanine, and histidine’s imidazole is no substitute for them, so purity is read in the low UV where the peptide bond absorbs. The acidic trifluoroacetic acid mobile phases standard in peptide HPLC can also dissociate copper coordination on the column, which means a trace may be reporting on free peptide, on complex or on both, depending on the method; free and incompletely complexed material can show up as separate peaks.

A purity percentage therefore does not prove the copper is fully bound, and copper stoichiometry is its own measurement, made by an elemental technique such as atomic absorption or ICP. On a mass spectrum the complex reads about one dalton lighter than peptide plus copper, reflecting the lost amide hydrogen. GHK-Cu 50mg has its independent HPLC record displayed here; the vial bears no lot code, so a copper-peptide vial is paired with that record by crimp and cap color alone.

Research contexts for GHK-Cu

• Copper(II) coordination chemistry and complex-stability measurements
• Metal-peptide speciation methods that combine HPLC with elemental analysis
• Gene-expression assays in fibroblast and keratinocyte cell cultures
• Comparative analytical work on free GHK versus the copper complex
• Visible-region spectroscopy of copper(II) d-d transitions

GHK-Cu 50mg is supplied for in-vitro laboratory and analytical research and is not intended for application to people or animals.

GHK-Cu questions

Are GHK and GHK-Cu interchangeable?

No. GHK is the free tripeptide and GHK-Cu is its copper(II) complex; they have different formulas, masses and CAS numbers and belong in a record as separate substances.

Why is the complex lighter than GHK plus one copper atom?

Binding copper strips a hydrogen from the backbone amide nitrogen between glycine and histidine, so the complex sits near 402.9 rather than 403.9 g/mol.

Why does GHK-Cu look blue?

The color comes from copper(II) d-d transitions in the peptide’s binding site, which absorb visible light. It indicates the complex is present but cannot show how much of the peptide is complexed.