Glutathione in Health and Disease Glutathione (GSH) and NAD are both critical for cellular health, energy, and repair. Yet, they function very differently in the body. The question I'm often asked is, "Which one do I need Glutathione synthesis. Semantic Scholar Glutamylcysteine SynthetaseGlutathione Synthetase: Domain Structure and Identification of Residues Important in Substrate and Glutathione Binding Biochemistry GSH Science & Research AgelessRx