What Is GHK-Cu? (Copper Tripeptide-1, Defined)

GHK-Cu (Copper Tripeptide-1) is a naturally occurring complex of the tripeptide glycyl-histidyl-lysine with a copper(II) ion. It was identified in human plasma in 1973 by biochemist Dr. Loren Pickart, who spent five decades studying it. In skincare it appears on ingredient lists as Copper Tripeptide-1, and it is the molecule behind most "copper peptide" products, though not all of them actually use it.

The essentials

INCI name Copper Tripeptide-1
Structure Gly-His-Lys tripeptide complexed with Cu(II); the copper is bound, not covalently attached
Discovered 1973, Loren Pickart (human plasma studies)
Natural role Present in plasma, saliva, and urine; reported to decline with age
Studied for Collagen synthesis, wound biology, hair follicle biology, antioxidant and calming actions, gene expression
Evidence status Strong laboratory record since 1988; human clinical trials remain few and small. Full breakdown in our research library.
Typical use Leave-on serums; disclosed concentrations on the market range from 0.10% to 3%
Color The Cu(II) complex is naturally blue; a genuine GHK-Cu serum is usually blue-tinted

What GHK-Cu is not

Not every "copper peptide" is GHK-Cu. Copper PCA is a copper salt with no peptide. Copper Palmitoyl Heptapeptide-14 is a different peptide entirely. Some legacy formulas combine hydrolyzed proteins with copper chloride and describe the result as copper peptides. The published GHK-Cu research applies to GHK-Cu; check the INCI list, not the marketing.

Go deeper

The GHK-Cu Research Library (60 verified studies, plain English) · Concentration by brand · How to use copper peptides · Side effects · The copper uglies · Glow, our GHK-Cu serum (0.2% disclosed)

Maintained by MAXXING Editorial, reviewed by founder Habib A. Muflih. Educational reference, not medical advice. Last updated August 2026.

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