GHK-Cu is a small copper-binding peptide first isolated from human plasma in the 1970s. On an ingredient list you will see it as copper tripeptide-1: three amino acids (glycine, histidine, lysine) holding a single copper ion. That copper is the point — it is what turns an ordinary tripeptide into one of the most-studied “signal” peptides in cosmetic science (Pickart & Margolina, Int. J. Mol. Sci. 2018).
What GHK-Cu is
Peptides are short chains of amino acids. Skincare peptides are usually grouped into signal peptides, carrier peptides and enzyme-inhibiting peptides. GHK-Cu sits in the first two buckets: it acts as a messenger and it carries copper, a trace element skin uses in several structural processes. Because it is a naturally occurring fragment, it is one of the better-understood peptides in the literature rather than a purely marketing-led ingredient.
The cosmetic benefits studied
In laboratory and small human-use studies, GHK-Cu has been associated with the appearance of firmer, smoother, more even-toned skin and with support of the skin barrier (Pickart & Margolina, Int. J. Mol. Sci. 2018). Reviews of copper in skincare more broadly describe roles in the look of skin resilience and tone (Borkow, Curr. Chem. Biol. 2014). Framed honestly for a cosmetic product, that translates to: skin that looks better supported over weeks of use — not a medical treatment for any condition.
- Firmness & bounce. The most-cited reason people reach for copper peptides.
- Even tone. Frequently reported alongside general “radiance” claims.
- Barrier feel. Often paired with humectants for a comfortable finish.
How to use it
GHK-Cu is typically sold as a leave-on serum in the 1–3–or-higher “copper peptide” percentage range. A simple approach:
- Apply to clean skin before heavier creams.
- Start once daily and build to twice as tolerated.
- Follow with a moisturiser; layer sunscreen every morning.
A long-standing debate is whether GHK-Cu should share a routine with direct vitamin C (ascorbic acid) or high-strength exfoliating acids, since very low pH and strong chelators can theoretically disturb the copper complex. The pragmatic answer for most people: use them at different times of day rather than mixing them in the same layer.
Who it suits
Copper peptides are generally well tolerated and are a common “gentle actives” choice for people who find retinoids irritating. As with any new product, patch-test first.
References
Pickart & Margolina, Int. J. Mol. Sci. 2018. Borkow, Curr. Chem. Biol. 2014.