Fraley What's the difference between GHK Cu (copper peptide) as a topical cream vs an injection? In this video I break down: What GHK Cu is and why it's used in anti aging skincare GHK Cu for Skin: SIGNAL's Guide to Rejuvenation GHK Cu is the compound your body made at 25 and quietly stopped making. Most people find it in overpriced serums. Few understand what it actually does, or what happens when you're not GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack?