After a year of using GHK Cu both topically and going deeper than topicals (under my doctor's care), the difference in my skin is not something I have to squint at in good 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 Advanced GHK Cu Face Cream 2400mg 4% Firmer Skin Neurogan Neurogan Health 7% GHK CU ACCELERANT Platinum Skin Care