Cellular Defense
The body's most abundant endogenous antioxidant — depleted ~10–15% per decade after age 20.
Glutathione is the master intracellular redox buffer, made from glycine, cysteine, and glutamate. Restoring it (by supplying the rate-limiting precursors, as in GlyNAC) is foundational because so many downstream defenses depend on adequate GSH.