GHK-Cu and collagen signalling: why the copper matters
The tripeptide GHK is small — three amino acids — but when bound to copper it becomes a potent modulator of skin and connective-tissue gene expression.
GHK is a tripeptide composed of glycine, histidine, and lysine. Alone, it exists naturally in human plasma at concentrations that decline sharply with age. Bound to a divalent copper ion, GHK forms GHK-Cu — a complex with a strikingly rich blue-purple colour and a distinctive biological profile.
The copper connection
Copper is essential to a family of enzymes called lysyl oxidases, which cross-link collagen and elastin fibres in the dermis. Without cross-linking, connective tissue loses tensile strength. GHK-Cu appears to shuttle copper directly to these enzymes, which is why its effects can't be replicated by GHK alone.
Gene-expression modulation
Genome-wide expression studies on human fibroblasts have shown that GHK-Cu up- or down-regulates thousands of genes, including those governing DNA repair, antioxidant defence, and extracellular-matrix remodelling. This wide reach is why GHK-Cu appears in signature blends alongside other tissue-support peptides.
Handling notes
GHK-Cu is unusually stable in lyophilized form. In solution, avoid prolonged exposure to strong reducing agents which can dissociate the copper.