What Is GHK-Cu? The Copper Tripeptide Explained

The peptide and the metal

GHK is glycyl-L-histidyl-L-lysine, an average mass of about 340.4 Da. It binds copper(II) through the histidine imidazole, the N-terminal amine and a backbone amide nitrogen, and the complex is what is called GHK-Cu. With copper counted, the listed mass is about 401.9 Da.

The complex gives solutions a blue color, which is a quick visual sign that copper is bound, though not a measure of purity.

Where it was found

The tripeptide was described in the 1970s as a factor in human plasma that co-isolated with copper. Later work measured its copper-binding constants and showed it can compete with albumin for copper(II) at neutral pH.

What cell studies examine

Published cell-culture work has examined collagen and glycosaminoglycan synthesis by fibroblasts exposed to very low concentrations of GHK-Cu, and gene-expression analyses in cell models. These are laboratory findings in cells; the GHK-Cu research overview lists the cited papers and their limits.

Handling notes for the lab

• pH matters: copper speciation changes with pH, so buffer choice affects what is actually in solution.
• Metal contamination: stray metal ions in water or glassware can compete for binding.
• Identity checks: mass spectrometry may show both the free peptide and copper adducts, which is expected.

Availability at Sealed Peptides

GHK-Cu is currently listed inside the Glow and Klow blends. A single-compound GHK-Cu vial is coming soon.