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 Copper Peptide (GHK CU) 1% Serum GHK Cu Copper Peptide: The Ultimate Peptide For Longevity Cellular Glow Copper Peptide GHK Cu Serum for Face Essential GHK Cu Serum: What It Is, How It Works, and Why It Matters f Bacteriostaticwater.com