In red blood cells the lack of glutathione leads to extensive peroxide attack on the plasma membrane, producing fragile red blood cells that readily undergo hemolysis.
It pairs well with Vitamin C, B-Complex, and hydration formulas for enhanced detoxification and skin health benefits
(PubMed) Peplow D, Edmonds R
Glutathione has many functions within the body including, supporting immune function, forming sperm cells, fighting free radicals, helping with certain enzyme functions, and making DNA
From there, it layers in brightening with 3-O-ethyl ascorbic acid and ascorbyl tetraisopalmitatetwo more stable, gentler vitamin C derivatives that help even tone over time without the sting you might get from L-ascorbic acid
However, with those results, I would certainly not be surprised to find SIBO