GHK-Cu: a gene-expression review is not a clinical trial

GHK (glycyl-L-histidyl-L-lysine) is a small copper-binding peptide with a long dermatologic literature. Pickart and Margolina’s 2018 review in the International Journal of Molecular Sciences is the document people cite when they want a single link for “gene data.” The authors argue that newer expression studies line up with older observations on remodeling, antioxidant defense, and tissue repair.

What a review of this kind can show

It can show that several laboratories, over many years, have reported transcriptional and cellular effects of the copper complex, and that those effects are biologically plausible for wound and skin models. Open-access reviews are useful precisely because a reader can see the citation list and notice how many items are cell culture, animal wounds, or cosmetic formulations rather than controlled medical trials.

What it cannot show

It cannot show that a 50 mg or 100 mg research vial, reconstituted at home, reproduces any figure in the paper. It cannot assign a systemic dose. Copper-peptide cosmetic studies, where they exist, use topical products with their own vehicles. Mixing those studies with injectable research material is a category error. The honest use of PMID 29986520 is as a map of mechanisms and as a reminder to open the underlying citations, not as a conclusion that the molecule is ready for use.