glutathione peroxidase enzyme Reaction mechanism of (GPX) Glutathione Peroxidases in Plants: Innumerable
Description
J Inherit Metab Dis (2014) 37(4):55363

and L.F.)

Biomedicines 10 (5), 1071

GGT5 is capable of hydrolyzing glutathione but not -glutamyl-p-nitroanilide, which is an ordinary substrate for enzyme-activity assay

You do not need to take a massive dose once a week
