Can I use Retinoids with Vitali GHK Cu Copper Peptides? How do I get t Vitali Skincare Copper Peptides vs. Retinol & Vitamin C: What to Choose? by DrBeautiology Medium Copper Peptides for Skin: What GHK Cu Does and How It Compares to Retinol 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.,