Glutathione is the body's primary internal antioxidant, made using the amino acid cysteine, and it helps protect cells from oxidative stress. Beyond detoxification, research shows glutathione is involved in thyroid hormone metabolism, How to Increase Glutathione to Protect Against Hashimoto's Arsenic Trioxide and Reduced Glutathione Act Synergistically to Augment Inhibition of Thyroid Peroxidase Activity In Vitro Biological Trace Element Research Springer Nature Link Glutathione peroxidase 4 inhibition induces ferroptosis and mTOR pathway suppression in thyroid cancer Scientific Reports