glutathion oxidation Glutathione/Glutaredoxin in Cellular Redox Homeostasis and Signaling Glutathione has also been identified as the thiol buffer that keeps sulfohydryl groups in the reduced form of many proteins Glutathione - Wikipedia

The concept of "normal" is based on the middle 95% of results, fitting within a typical bell-shaped curve

Its primary function is to serve as a powerful chain-breaking antioxidant, effectively preventing ROS formation during free radical reactions and the oxidation of fats

Gonzalez, P

Replenishing the nutritional status of the host by increasing vital amino acids such as cysteine to enhance GSH levels and selenium to improve selenium deficiency and facilitate selenoprotein (GSH peroxidases, thioredoxin reductases) expression can inhibit oxidative stress, modulating inflammation, suppressing endothelial dysfunction, and protecting vascular cells against apoptosis and calcification (He et al., 2017

You need to query it and get it re-tested