Glutathione

Glutathione (GSH) is a tripeptide consisting of glutamate, cysteine, and glycine that serves as the body's master antioxidant and primary defense against oxidative stress. Present in virtually all cells, glutathione protects against reactive oxygen species, supports detoxification of xenobiotics and metabolic byproducts, maintains other antioxidants (vitamins C and E) in their active forms, and plays essential roles in immune function and DNA synthesis. Research demonstrates glutathione levels decline with age and in numerous disease states including neurodegenerative conditions, liver disease, HIV/AIDS, and cancer. The reduced form (GSH) neutralizes free radicals and is regenerated by glutathione reductase using NADPH. Supplementation strategies include oral glutathione (with variable bioavailability), liposomal glutathione, intravenous glutathione, and precursor support (N-acetyl cysteine, glycine, glutamine). Research indicates benefits for liver protection, skin lightening, immune support, and athletic recovery. Optimal glutathione status is considered fundamental to cellular health and longevity.

Human evidence for therapeutic glutathione use is thin: most trials are small, open-label or adjunctive, and results are mixed. Oral absorption is negligible, IV formulations are not FDA approved for the marketed wellness indications, and long-term safety data for repeated IV administration are lacking.

Glutathione is a ubiquitous intracellular tripeptide (gamma-Glu-Cys-Gly) and the body's main endogenous antioxidant. As a supplement it is given orally (very poorly absorbed), intravenously, or by inhalation in various unapproved protocols; the IV route bypasses the low oral bioavailability demonstrated in pharmacokinetic studies.