GHK-Cu
GHK-Cu is the 1:1 copper(II) complex of the plasma tripeptide glycyl-L-histidyl-L-lysine, studied in cell-culture and matrix experiments.
Pickart and coauthors reported shifts in gene-expression panels, antioxidant readouts, and extracellular-matrix markers in dermal and cell models. The tripeptide also appears in cosmetic-ingredient writing. That is a different regulatory category from a research vial, and different again from an approved drug. This note stays with the laboratory theme: a small copper-binding peptide used in matrix and cell assays.
The peptide is Gly-His-Lys, complexed with copper. Counter-ion and purity belong on the certificate of analysis. The lyophilized format on a listing describes the solid, not a way to use it. Nothing here is a claim about skin treatment or personal use.