Copper peptides explained what are the differences between copper peptides and GHK CU peptides? What they actually do for the skin in terms of repair and collagen, and what you can and cant mix GHK Cu Peptide The benefits, side effects, and more [2026] 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 Copper, Collagen, and Controversy: Inside the GHK Cu Buzz