Glutathione

The body's main in-cell antioxidant. Feed it through its building blocks.

Mechanisms, studies and evidence grades for each claim above.

Functions

• Neutralizes reactive oxygen species
• Substrate for glutathione peroxidase reactions
• Participates in phase II detoxification via glutathione-S-transferase (GST)

Synthesis

Built from glycine + cysteine + glutamate, with cysteine usually the rate-limiting substrate of the three. See Glycine / Collagen and Cysteine for the upstream detail.¹

Mechanism

Redox cycling between reduced (GSH) and oxidized (GSSG) forms, driven by NADPH-dependent glutathione reductase — which is why B2 (riboflavin, via FAD) and adequate NADPH-generating capacity both matter for keeping the system running.¹

Intake / dosing

No established optimal oral dose — studies vary widely by formulation (liposomal, reduced GSH, precursor-based) and endpoint, and oral bioavailability of glutathione itself is limited, which is why precursors (glycine, cysteine/NAC) are often emphasized instead of glutathione directly.

Deficiency effects

Low glutathione status shows up in oxidative stress states rather than as a classic dietary deficiency.

Top foods

• Beef
• Salmon
• Turkey
• Onion
• Broccoli
• Cheese

References