Plasma Concentrations (ng mL) and Ingested Dose (mg) by Cannabis Download Scientific Diagram PDF) Regenerative and Protective Actions of the GHK Cu Peptide in the Light of the New Gene Data Expression and Purification of Recombinant GHK Tripeptides Are Able to Protect against Acute Cardiotoxicity from Exposure to Waterborne Copper in Zebrafish 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 The tripeptide GHKCu complex ameliorates lipopolysaccharideinduced acute lung injury in mice Oncotarget