GHK Cu Copper Peptide HPLC Tested Peptide Warehouse A lot of people asked how I use GHK Cu (copper peptide) with a pen device, so here's a quick tutorial showing exactly how I do it. In this video I show how USA Copper Peptide GHK Cu Powder, DIY Blue Copper for Making the Best Face Cream Amazon.com: Neurogan GHK Cu Copper Peptide Hair & Scalp Serum 2400mg, 4% Copper Peptides Fast Absorbing, Water Based Formula for Hair Softness & Shine Cosmetic Dry Scalp Moisturizer Spray, Made in USA : Injectable GHK Cu: Beginner's Guide to Copper Peptide