What is GHK Cu and Why is Everyone Talking About It? GHK Cu (Copper Peptide) is a powerful, naturally occurring compound in the body that plays a key role in skin health GHK Cu Peptide Before and After Results 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 uglies = temporary. When you start GHK Cu, you can get a spike in free copper breakouts, texture, irritation. It's not the peptide failing. It's your body adjusting. Happens fast