glutathione paula's choice 25% Vitamin C Serum with & Antioxidants, Face Serum Improves Discoloration, Uneven Tone & Firms, All Skin Types, Fragrance-Free, 1oz : Beauty & Personal Care elasticity and firmness without irritation Paula's Choice 25% Vitamin C

It participates in the modulation of the activity and localization of numerous enzymes and receptors [147, 160, 161], takes part in the regulation of many physiological processes in the brain [147, 162], including synaptic plasticity [163, 164], axonal elongation, and neuronal survival [147, 165]

Smith RG, Van der Ploeg LH, Howard AD, et al

A widely cited microarray screen reported that GHK exposure of human fibroblast cultures altered expression of more than 4,000 genes, with pathway analysis identifying TGF-, integrin, and ubiquitin-proteasome signaling as enriched among GHK-responsive transcripts

This might help with better energy production in your cells, stronger immune function, and protection from age-related wear and tear