A GHK Cu face serum appears blue because the active ingredient, GHK Cu (copper peptide), is naturally a blue colored powder, meaning its inherent color transfers to the serum when mixed in; this blue hue GHK Copper Peptide GHK Cu Tripeptide 1 Skin Perfection Ghk Cu Copper Peptide Powder 99.7% Pure Diy Ghk Powder to Make a Serum for Face Hair Scalp 1g GHK CU: How to Mix It The Peptide Report GHK Cu Dosage and Protocol: A Medical Provider's Guide to the 30 Day Cycle Perfect B