The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu Dosage Calculator GHK Cu Copper Peptide Reconstitution How long will a 50 mg supply of GHKCu last when dosing 2 mg daily for five consecutive days followed by two days off each week? I've been getting a lot of questions about GHK Cu, so here's a quick breakdown. GHK Cu is a copper peptide that naturally occurs in the body and plays a role in skin repair