GHK Cu Copper Peptide Collagen Boost & Skin Regeneration Calibrate Hydration 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 GHK CU 100mg 99%+ Purity, COA Verified Copper Peptides Serum for Face 2% GHK CU & 4% EGF Seraphime GHK Cu Peptide Therapy Brea, CA Orange County Skin Restoration: Prioritizing Safety Over Trends