Best Copper Peptide Serum The top 4 options of 2026 GHK Cu Peptide Serum 30 ml, Copper Peptide Serum with Hyaluronic Acid for Tightening, Collagen Boosting Defy GHK Cu (glycyl L histidyl L lysine) is a naturally occurring copper binding peptide found in human plasma. As levels decline with age, so may its support of the biological processes involved in collagen production, skin 2% GHK CU Copper Peptide Serum for Hair Growth and Scalp Care GHK Cu (copper peptide) is a science backed anti aging compound that supports collagen production, skin regeneration, and overall skin health. Used in both topical serums and subcutaneous