GHK-Cu: skincare and laboratory research

The copper complex is part of the identity

GHK describes a particular amino acid sequence. Cu denotes the copper in the complex. GHK and GHK-Cu should therefore not be described as fully interchangeable substances. In 1988, Maquart and colleagues described GHK's affinity for copper ions and investigated the copper complex's effect on fibroblasts.

In a research report, the name must be read alongside the description of the experimental material. Details of the chemical form and certificate of analysis allow an assessment of whether the material matches what a study describes. A sample's colour or a familiar trade name is not sufficient identification.

What the cell experiments examined

Maquart and colleagues' 1988 study reported stimulation of collagen synthesis in fibroblast cultures. Fibroblasts are cells that produce connective tissue components, among other functions. The measurement describes the response in this experimental model, in which cells were examined under specific laboratory conditions.

In 1992, Wegrowski, Maquart and Borel investigated glycosaminoglycan synthesis in cultured human fibroblasts. They found changes in some of the components examined, but no effect on hyaluronic acid synthesis. The result also showed a concentration-dependent profile, so it cannot be described as a general increase in all parts of the skin's supporting structure.

A claim about visible skin changes requires a different experimental design. Increased synthesis in cultured cells does not reveal how much of a compound reaches relevant cells in intact skin, or whether people experience a measurable cosmetic improvement.

Skin transport must be measured in the relevant model

The study “Human skin penetration of a copper tripeptide in vitro as a function of skin layer” was published online in 2010 and in the journal issue in 2011. Researchers investigated the transport and retention of copper from a GHK-Cu solution in different skin layers. They used skin samples in a laboratory setup. This is a different type of evidence from a clinical trial of a finished skincare product.

A 2008 study also investigated the transport of copper complexes with peptides through a model of the stratum corneum. Such experiments can shed light on barriers and transport mechanisms. They must be interpreted in light of the model, vehicle and what the analytical method actually recorded.

When reading a transport study, it is particularly relevant to distinguish copper measurement from identification of an intact peptide complex. A signal from one element cannot by itself establish that the whole complex is present unchanged. This must be examined in the study's methods and interpretation.

A finished formulation has its own properties

A cream or serum contains ingredients other than the peptide. When such a product is tested, the result applies to the formulation as a whole. It can be difficult to attribute a change to one ingredient unless the experiment includes a suitable comparison with the same formulation without that ingredient.

The EU Cosmetics Regulation requires a safety assessment and safety report for the finished cosmetic product before it is placed on the market. The report covers composition, stability, microbiological quality and exposure, among other matters. A certificate of analysis for one raw material does not replace such a product assessment.

A reference to GHK-Cu in skincare literature therefore does not establish that a laboratory powder is suitable as a cosmetic product. This article does not provide recipes or instructions for making such formulations.

Keep the experimental model linked to the claim

When reviewing a GHK-Cu study, four details should be clear: which material was examined, which model was used, what the control was and which endpoint was measured. A publication about fibroblasts should be described as a cell study; a transport study as an investigation of transport.

For studies of finished cosmetic products, the formulation, participant group and duration must also be stated. Labels such as clinically investigated provide little information if the reader is not told which product was examined and what the experiment could establish.

ArcticAmino provides access to the batch's certificate of analysis on request before ordering. The document can be used to assess the analysed sample. It does not establish skincare efficacy, medical efficacy or that the raw material can be used in humans.