Full article: Enzymatic cross linking of collagens in organ fibrosis resolution and assessment JCI 11 Hydroxysteroid dehydrogenase blockade prevents age induced skin structure and function defects Introduction GHK Cu is a copper peptide complex formed from the tripeptide glycyl L histidyl L lysine bound to copper. This compound has garnered significant attention in both laboratory and formulation research due to its critical role GHK Cu G Lab Peptides The challenge of determining lysyl oxidase activity: Old methods and novel approaches ScienceDirect Glycation of type I collagen selectively targets the same helical domain lysine sites as lysyl oxidasemediated cross linking Journal of Biological Chemistry