Viral claim says GHK Cu reset nearly 4,000 genes to a younger state and increased collagen production in a preclinical study. This refers to research on GHK Cu, a naturally occurring copper binding peptide that Sublingual GHK Cu TruHealth Physical Therapy GHK Cu: The Regenerative Peptide for Skin, Hair, and Healing Pulse & Remedy GHK Cu is a naturally occurring tripeptide in human plasma. Levels average 200 ng ml at age 20 and drop to 80 ng ml by age 60 (Pickart et al., 2020). That decline tracks with GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Protective Functions of Alanyl L Histidine and Glycyl L Histidyl L Lysine Glycoconjugates and Copper in Concert