GHK-Cu, the copper peptide: what it is and what it is for

What GHK-Cu is

GHK is a tripeptide (three amino acids: glycine, histidine and lysine) described in human plasma in studies from the 1970s and 1980s. It binds a copper(II) ion tightly; the resulting complex is GHK-Cu, known as the copper peptide.

In solution at neutral pH it forms mainly a 1:1 complex (one copper per peptide), held by nitrogens that include the histidine ring. A 2:1 form also exists, and copper exchanges quickly between GHK molecules. That is why PubChem keeps separate records for the free peptide and for each complex.

Its mass is about 402.9 g/mol (PubChem CID 71587328). Free GHK, without copper, is a different substance: 340.4 g/mol.

What GHK-Cu is used for

In cosmetics, GHK-Cu is used in topical skin and hair products under the INCI name copper tripeptide-1. That use as a cosmetic ingredient is legal and does not make it a medicine.

In the laboratory, its coordination chemistry (how it binds and releases copper) is studied, it is used as a copper "tag" to help crystallize proteins, and it is investigated in cell cultures and animal models. Results in cells or animals cannot be carried over to people.

As an injectable medicine, there is no FDA-approved GHK-Cu product. The agency lists it in its compounding bulk-substance categories, which is not an approval, and said it would consult its advisory committee about GHK-Cu before the end of February 2027. FDA considers human data limited.

Copper peptide in a cream vs in a vial

• Cosmetic cream or serum: a finished product at low concentration, regulated as a cosmetic and meant for skin.
• Research vial: blue lyophilized GHK-Cu powder sold as a laboratory reagent. It is not a cosmetic or a medicine.

If you want a skin product, look for a cosmetic. Our GHK-Cu in 50 and 100 mg vials is research material.

Blends with GHK-Cu

GHK-Cu also comes combined with other peptides in one vial: GLOW (GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg) and KLOW (the same plus 10 mg KPV). There are no published studies of these combinations, and whether the copper interacts with the other peptides in solution is unknown.

What to check on a GHK-Cu COA

• Identity by mass spectrometry, consistent with the GHK peptide and its copper complex.
• Peptide purity by HPLC. Because copper is released under acidic conditions, a strongly acidic HPLC run mainly measures the peptide, not the intact complex.
• Copper content measured separately (by ICP-MS or ICP-OES), with the copper-to-peptide ratio, since 1:1 and 2:1 forms exist.
• Appearance: the blue color of copper(II) should be recorded.

More in how to read a COA.

Storage

Store it as its COA and label state: cold, dry and away from light. GHK-Cu is stable under moderate redox conditions, but in a strongly reducing medium copper(II) can be reduced to copper(I) and released; mixing it with reducing agents in an experiment changes what is in solution.