preclinical studies.

What do GHK gene-expression studies reveal about nervous-system research, and what remains unproven?

GHK (glycyl-L-histidyl-L-lysine) gene-expression studies suggest this peptide modulates numerous genes relevant to nervous system health, including those involved in nerve outgrowth, antioxidant defense, DNA repair, and protein clearance. However, most evidence comes from in vitro, animal, and computational models, not controlled human trials. The translation of these findings to clinical outcomes remains unproven, and substantial limitations exist.