GHK Cu is a naturally occurring tripeptide in human plasma. Levels average 200 ng ml at age 20 and drop to 80 ng ml by age 60 (Pickart et al., 2020). That decline tracks with Copper peptides like GHK Cu work by sending signals to your skin to repair, regenerate, and produce collagen. It's not about instant results, it's about improving how your skin functions over time. Dr. By age 30, your skin produces about 25% less collagen. By 40, that number can reach 40%. This decline affects more than just how your skin looks. It changes how it heals, Copper Peptide Duo GHK Cu Anti Aging Serum & Moisturizer Copper Tripeptide (GHK Cu) for Advanced Skincare & Haircare Formulatio