GHK-Cu

A three-residue peptide and a copper(II) ion, held together as one species. The blue colour is not a dye and not a defect — it is the copper, and a GHK-Cu powder that is white is not GHK-Cu.

Class: Copper(II) complex of a synthetic tripeptide
Also written: Copper tripeptide-1; GHK-copper; Gly-His-Lys Cu(II)
Peptide formula: C₁₄H₂₄N₆O₄ (free GHK)
Peptide molecular weight: 340.38 g/mol (free GHK)
Complex: 1:1 GHK to Cu(II). Published molecular weights for the complex vary with the protonation state assumed, so no single figure is given here.
CAS number: 49557-75-7 (free GHK tripeptide)
Appearance: Blue lyophilised powder
Purity specification: 99%+ by HPLC
Vial size stocked: 100 mg

Sequence

G H K · Cu(II)

Gly-His-Lys, coordinated to a copper(II) ion. Coordination is through the N-terminal amine, the deprotonated backbone amide, and the imidazole nitrogen of the histidine — which is why the histidine is not interchangeable and why the sequence order matters as much as the composition.

Origin

GHK is a naturally occurring tripeptide first isolated from human plasma. The peptide sold here is made by synthesis and then complexed with copper; it is not extracted from plasma. Copper is a constituent of the molecule as supplied, not an additive — separating the two gives you a different substance with a different molecular weight and a different colour.

Solubility

Freely soluble in water. Solutions are blue, and the depth of that blue tracks concentration closely enough to be a rough visual check. Avoid chelating buffers such as EDTA, which will compete for the copper and take the complex apart.

Storage and handling

Lyophilised powder: store at −20 °C, protected from light and moisture.
Keep away from strong chelators and from reducing agents, either of which will disturb the copper coordination.
In solution: refrigerate and protect from light. Copper complexes are photosensitive.
A solution that has gone from blue to colourless has decomposed. Colour is the readout here.
Label every reconstituted vial with compound, lot, concentration and date.

How your lot is verified

An independent third-party laboratory tests the material first, then we test it again in-house when it arrives — purity by HPLC, identity by mass spectrometry — and only then does it ship. How we verify.

View GHK-Cu 100 mg

Supplied for laboratory research use only. Not for human or veterinary use. No statement on this page has been evaluated by the Food and Drug Administration, and nothing here is intended to diagnose, treat, cure, or prevent any disease. Alpha Aminos is a chemical supplier and does not provide guidance on the use of any compound.