GHK-Cu is a small peptide made of three amino acids (glycine, histidine, lysine) bound to copper. It is one of the most discussed ingredients in cosmetic peptide skincare, so it is worth looking closely at the evidence.
What is known
GHK is a naturally occurring tripeptide found in human plasma, saliva and urine, and reviews report that its level declines with age. Review articles by Pickart and colleagues summarize laboratory and animal work suggesting that GHK-Cu takes part in wound repair and tissue remodeling, including effects on collagen and other structural proteins in cell studies. The same reviews describe controlled cosmetic studies on aged skin reporting improvements in firmness, elasticity and the look of fine lines.
What the limits are
- Conflicts of interest. Much of the published GHK-Cu literature comes from authors with commercial ties to GHK-based products. That does not make it wrong, but it is a reason to want independent replication.
- Reviews are not trials. The sources above are review articles. They collect earlier findings rather than testing a specific product.
- Dose and formula matter. Concentrations, copper ratios and the other ingredients in a formula change how the peptide behaves. Copper-binding also means some formulation choices, such as certain chelators, can interfere with it.
- Cosmetic scope. Cosmetic studies look at appearance, such as smoothness or firmness. They do not show that a product changes how skin works or addresses a medical condition.
How we think about it
At Ieso Skincare we use GHK-Cu as one ingredient in MATRIX and we say plainly that the research we cite is about the ingredient, not about MATRIX. We plan our own study in people so that, over time, we can point to data on the finished formula instead of borrowing it.
Questions to ask any GHK-Cu product
- What concentration does it contain?
- Is copper present as GHK-Cu, and is the formula designed around it?
- Is the evidence cited about the finished product or the ingredient alone?
This article is educational and is not medical advice.
Sources: Pickart et al., 2015; Pickart, 2008.
