GHK-Cu
Copper tripeptide from human plasma
A naturally occurring tripeptide that binds copper(II) and whose plasma concentration declines with age. Studied in cell culture and animal models since the 1970s, particularly well documented in skin research.
Gly-His-Lys · Cu(II)
At a glance
- 01
A peptide that carries a metal
GHK binds copper(II) with high affinity and forms a blue-violet complex. It is therefore a model for how peptides can transport metal ions and deliver them to cells.
- 02
Concentration declines with age
In the plasma of young adults GHK is around 200 ng/ml, at age 60 around 80 ng/ml. This decline is one reason the peptide is studied in ageing research.
- 03
Gene expression at scale
In database analyses (Connectivity Map), GHK-Cu altered the expression of roughly a third of the human genes examined. Such broad effects are unusual for so small a molecule and the subject of ongoing research.
- 04
Well documented in skin research
GHK-Cu is one of the few research peptides for which controlled human studies exist, although in topical application in cosmetics. Those data do not transfer to other forms of use.
Fields of research
- Copper transport and metal binding
- Collagen and matrix biology
- Skin ageing and wound models
- Antioxidant enzymes
- Gene expression studies
What it is
GHK is one of the smallest peptides with a biology of its own: just three amino acids, glycine, histidine, lysine. The histidine residue binds copper(II) and forms the eponymous complex GHK-Cu. In the body the peptide arises, among other things, from the breakdown of collagen and other matrix proteins, so it is a signal that tissue is being remodelled.
What makes it special
Two things. First, the metal complex: GHK-Cu is one of the few research peptides that not only interacts with a receptor but itself carries and releases a metal ion. Copper is a cofactor of numerous enzymes, such as lysyl oxidase for collagen cross-linking or superoxide dismutase.
Second, the gene expression data. Pickart and Margolina compared GHK-Cu with the Broad Institute’s Connectivity Map dataset and found broad effects on genes related to tissue regeneration, DNA repair and antioxidant systems. Such database findings generate hypotheses, they are not proof of effect, but they explain the wide interest.
What the studies say
The review by Pickart and Margolina (2018) summarises five decades of research: in cell culture GHK-Cu promotes the synthesis of collagen, elastin and glycosaminoglycans, in animal models effects on wound healing are described. In humans, topical application in cosmetics has been studied, with effects on skin density and wrinkle depth. The authors are also the developers of the peptide, which should be borne in mind.
State of evidence
Preclinical: extensive. Clinical: limited, topical only. GHK-Cu is the longest-studied peptide in our range. The human data concern exclusively cosmetic skin applications and say nothing about other forms.
Research status
GHK-Cu is widespread as a cosmetic ingredient but not approved as a medicine. PURA LABS supplies GHK-Cu as a pure substance for research use only, not for human or animal use.