This Gentle Ingredient Is Research Proven To Build Collagen And Smooth Wrinkles. Here's How To Use It. Copper Peptide Serum Anti Aging Face Oil for Glowing Skin The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline People are turning themselves into lab rats': the injectable peptides craze sweeping the US Well actually The Guardian Uses and Benefits #ghk GHK Cu is a naturally occurring peptide in human plasma that declines with age. When used in injections (usually subcutaneous), it can offer various benefits: Skin Rejuvenation and Anti Aging: What Is Peptide Therapy and Is It Safe?