melatonin l glutathione as a master regulator of cell death and inflammation: molecular mechanisms and clinical implications for newborn care Comparative effects of melatonin, glutathione

The peptide is endogenously present in human plasma at low nanomolar concentrations in young adults, with the concentration declining with age (a finding from the original GHK research literature that is frequently cited in discussions of the compound)

If you want to stay healthy and live to a ripe old age, definitely supplement with Vitamin C

It's also used to treat Crohn's disease (a disorder in which the immune system assaults the digestive tract lining, resulting in discomfort, diarrhoea, weight loss, and fever) and other immune disorders (conditions that develop when the immune system attacks healthy cells in the body by mistake)

Cellular methylation pathway investigation