GHK-Cu and the skin barrier: how laboratories measure permeation

GHK-Cu, the copper complex of the tripeptide glycyl-L-histidyl-L-lysine, is one of the most studied small peptides in skin research. A recurring question in that research is a physical one: how much of it gets through the skin's outer layer at all?

Why it is a hard question

GHK-Cu is fairly hydrophilic, and the outermost layer of skin, the stratum corneum, is lipophilic. A 2025 review by Ogórek and colleagues describes this mismatch as the main limit on its permeation (Molecules, 2025).

Liposomes as carriers

One approach studied is to encapsulate GHK-Cu in liposomes, small lipid vesicles. The same review found that the transport of liposomes containing GHK-Cu "received little attention" in published work, and calls it a research gap.

How permeation is measured

The review summarises the methods used for compounds like GHK-Cu, free or encapsulated: diffusion-cell experiments on skin samples or membranes, followed by analytical measurement of the compound in each layer and in the receiving fluid. Our guides to HPLC and mass spectrometry explain the two analytical methods most often used.

Copper matters in the design

Free GHK, free copper and the GHK-Cu complex can behave differently in the same experiment, so a study should document which form was used and how it was prepared. See what is GHK-Cu.

Status in Canada

Health Canada names GHK-Cu in its April 2026 advisory on peptides bought online.

Ordering GHK-Cu for laboratory research

Peptune supplies GHK-Cu 50 mg as a lyophilized reference material for in vitro and analytical work, with the batch certificate on the product page. Orders ship across Canada by tracked mail: $20 or $25 depending on the province, free on orders of $150 or more. Payment is by Interac e-Transfer or crypto.

For laboratory research use only. Not for human or veterinary use. Nothing here is medical or cosmetic advice.