glutathione biosynthesis pathway The System: A Journey from Cyanobacteria to Higher Eukaryotes REGULATION OF GLUTATHIONE SYNTHESIS -

Notably, research has shown that higher glutathione levels (GSH) in the nucleus accumbens are linked with better and more consistent performance in effortful tasks in both preclinical models and humans

it's an evolving field of discovery

An enzyme called tyrosinase is needed to create melanin (the pigment that causes the brown spots) and while several other skin lightening agents work to inhibit the synthesis of tyrosinase itself (like vitamin C or licorice), arbutin lets tyrosinase be and rather hinders the melanin-forming activity of the enzyme

There arent severe side effects associated with nootropics in peptides