GHK (glycyl-L-histidyl-L-lysine) forms a complex with copper in order to form GHK-Cu. GHK-Cu is a peptide that has been shown to play a role in skin repair and wound healing. By supplementing GHK-Cu, there is an increased synthesis of collagen, decorin, chondroitin sulfate, and dermatan sulfate. GHK-Cu was shown to attract immune system cells and endothelial cells to injury sites. Furthermore, a study conducted by Pickert et. Al found that GHK-Cu increases the rate of wound healing decreases rejection of transplanted skin grafts, and even has anti-inflammatory properties.