What is the safe topical dosing, duration, and contraindications for the copperbinding peptide GHKCu for wound healing or antiaging? Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with Growth Hormone and Aging Endotext NCBI Bookshelf Copper Peptide (GHK Cu): Clinical Uses, Stability & Compounding Tips GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? 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