GHK-Cu: The Copper Peptide, Studied for Five Decades
Few cosmetic ingredients have as long a scientific record as GHK-Cu. The tripeptide glycyl-histidyl-lysine, complexed with a copper ion, was first isolated from human blood plasma in 1973. Half a century later, it remains one of the most researched peptides in the cosmetics field — and its distinctive blue color makes it instantly recognizable in formulations.
What GHK-Cu Is
GHK-Cu is a short peptide with the sequence glycine-histidine-lysine. By itself, the tripeptide GHK is unremarkable; its activity depends on forming a stable complex with a copper ion (Cu²⁺). The copper sits within the peptide’s structure, and this metal-peptide complex is what gives the molecule its characteristic properties — including the vivid blue color seen in high-purity material and in products containing it.
Where It Comes From
GHK was first identified in human plasma, where it occurs naturally as a fragment involved in tissue maintenance processes. Its copper-binding ability was recognized early on, and synthetic GHK-Cu has been produced since the 1970s using standard solid-phase peptide synthesis. The synthetic material is chemically identical to the naturally occurring complex.
How It Is Used in Skincare
In cosmetic formulations, GHK-Cu is included in serums, creams, and after-procedure products. Formulators value it for its well-documented history and its compatibility with a wide pH range compared with some other peptides. Its blue color must be accounted for in formulation — it can tint white creams, which is both a feature and a formulation consideration.
Stability and Formulation
GHK-Cu is more robust than many peptides, but it still requires sensible formulation practice: avoid extreme pH, protect against prolonged heat, and choose compatible preservatives. Suppliers provide stability data and recommended usage parameters with the ingredient.
Cosmetic Status, Not Drug Status
GHK-Cu in cosmetics is a cosmetic ingredient. It is used for cosmetic purposes in skincare products and is not a drug; any marketing must stay within cosmetic claim boundaries. Its decades of published research make it a well-documented choice for formulators seeking an ingredient with a substantial scientific history.
Original educational article. Sources: GHK-Cu — Wikipedia; The copper peptide GHK-Cu in skin biology (PMC review).