GHK-Cu Contains Copper as a Chelated Complex
GHK-Cu is not a copper receptor—it is the tripeptide GHK (glycyl-L-histidyl-L-lysine) that has already bound to a copper ion (Cu²⁺), forming a stable copper-peptide chelate complex. 1
Chemical Structure and Copper Binding
GHK is a naturally occurring tripeptide (glycine-histidine-lysine) found in human serum at concentrations averaging 200 ng/mL at age 20, declining to 80 ng/mL by age 60 1
The peptide has extremely high affinity for copper (Cu²⁺), with binding affinity similar to the copper transport site on albumin, and forms the stable chelate complex GHK-Cu 2
When you use "GHK-Cu," you are administering the peptide that already contains copper bound to it—the copper is an integral part of the molecular complex, not something it seeks out after administration 1
Copper-Free GHK vs. GHK-Cu
Both copper-free GHK and copper-bound GHK-Cu demonstrate biological activity, though they may work through different mechanisms 3
Copper-free GHK can increase stemness and proliferative potential of epidermal basal cells through increased integrin expression, showing similar effects to copper-GHK in skin models 3
GHK without copper can bind to and chelate free copper ions in biological systems, reducing copper redox activity and preventing copper-induced protein aggregation and cell death 4
Clinical Implications
If you purchase or use a product labeled "GHK-Cu," you are getting approximately 1 copper ion per peptide molecule in a pre-formed chelate complex 1, 2
The copper in GHK-Cu is tightly bound and bioavailable, contributing to the compound's anti-inflammatory, tissue remodeling, and antioxidant properties 2
GHK-Cu provides both the peptide signaling effects and copper delivery, whereas copper-free GHK provides peptide effects and can chelate excess free copper from the environment 4
Common Pitfall to Avoid
Do not confuse GHK-Cu with a "copper receptor" or transport protein—it is a small molecule chelate where copper is already chemically bound to the peptide. The distinction matters because copper-free GHK and copper-bound GHK-Cu have overlapping but distinct biological activities 3, 4.