Selected Biomarkers Revealed Potential Skin Toxicity Caused by Certain Copper Compounds Scientific Reports If your GHK Cu or MOTS C injection leaves welts and burns like a hornet, it's usually not the peptide it's the technique. A few small tweaks can turn a sting into almost GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy PSA] Albeit rare Copper peptide "uglies" are real and scary. Case report and looking for advices : r SkincareAddiction