does glutathione reduce oxidative stress Therapeutic potential of glutathione-enhancers in stress-related psychopathologies Glutathione: Master Antioxidant, Reducing Oxidative

in 2014 (ref

W., Freinkman, E., Wang, T., Birsoy, K

And more importantly, you're not necessarily doing anything wrong

Silico docking (Schrodinger Inc., Small-Molecule Drug Discovery Suite, 2016-1) revealed that benserazide binds to the active site of CBS (PDB ID: 1JBQ) and reacts with the PLP cofactor to form a reversible but kinetically stable Schiff base, and its trihydroxybenzyl ring can form hydrogen bonds with polar residues located in the peripheral cavity (such as His203, Tyr223, and Tyr308), resulting in strong inhibition

A Summary Davins viewpoint on glutathione for melasma, pigmentation & skin lightening

However, it requires consistent sessions and proper aftercare