The Molecule

What Is GHK-Cu?

Please note: This page covers chemistry and biology only. It gives no guidance on personal use.

GHK is one of the smallest peptides with a known biological role: just glycine, histidine and lysine joined in a chain. On its own it weighs about 340. Its defining feature is how strongly it binds copper.

How It Holds Copper

Studies in the early 1980s showed that at normal body pH, one GHK molecule binds one copper(II) ion. Nitrogen atoms, including one from the ring of histidine, grip the metal. The arrangement resembles the copper-carrying site on albumin, the main protein in blood plasma. This led scientists to suggest that GHK may help move copper into cells.

Where It Is Found

Body fluids: GHK has been measured in human plasma, saliva and urine.
Inside collagen: the same three-amino-acid sequence occurs in one of the chains of type I collagen. Researchers have proposed that it could be released when collagen is broken down at a wound.
Changes with age: reviews report that levels in the blood fall as people get older.

GHK or GHK-Cu?

	GHK / GHK-Cu
What it is	The bare peptide / The peptide bound to copper
Colour in solution	Colourless / Blue
In the body	Occurs naturally / Forms readily because GHK binds copper from its surroundings
In products	Rarely sold alone / Common in cosmetics as copper tripeptide-1

In many papers the two names are used almost interchangeably, because GHK picks up copper so easily from its surroundings.

Summary

GHK-Cu is a three-amino-acid peptide bound to one copper ion.
It occurs naturally in human body fluids, and its levels drop with age.
It may act partly by delivering copper to cells.
It is sold in cosmetics, but it is not a licensed medicine.