ION BLUE's Video on X Breaking: more people are starting to explore copper peptides over retinol Not because retinol is bad but because people are beginning to understand how different ingredients actually work. GHK Cu is something your Why You Shouldnt Mix GHK Cu with AHA, BHA, or Retinol If youre using a GHK Cu (Copper Peptide) in your skincare routine, layering it with strong actives like AHA, BHA, or retinol may actually reduce GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective?