Glutathione

In simple words

Glutathione is a short peptide made of three amino acids and the cell's main defender against oxidative damage. It is being studied as an antioxidant involved in neutralizing toxins and in immune function.

What this molecule is

Tripeptide: γ-Glu-Cys-Gly. The main intracellular antioxidant. ~307 Da. Forms: reduced GSH, S-acetyl-GSH, liposomal, GlyNAC (precursors).

Why it is studied

The cell's main redox buffer. RCTs: oral 250–1000 mg/day → ↑blood GSH, ↓oxidative stress. Liposomal: 6× higher bioavailability vs regular. GlyNAC (glycine + NAC) — correction of deficiency in older adults.

How it works

Electron donor for peroxidases → neutralization of H₂O₂ and peroxides. Conjugates toxins (phase II detoxification). Regenerates vitamins C and E. ↑NK cells and lymphocytes (immune function).

Doses used in studies

Studies used 250–1000 mg/day orally; the liposomal form — 250–500 mg/day (↑bioavailability); IV or IM — 600–1200 mg (clinics); GlyNAC — glycine 2.4 g + NAC 1.8 g/day.

Combined with in studies

• NAD+/NMN — redox synergy
• Vitamin C — regenerates GSH
• ALA — alpha-lipoic acid
• SS-31 — mitochondrial antioxidant

Level of evidence

Level A Human clinical trials. There are randomized controlled trials (RCTs), or the compound has been approved by a regulatory agency. The most reliable level. 5 RCTs. Well studied.

Important to know

Honest caveat: Oral GSH is rapidly broken down in the GI tract — liposomal or GlyNAC is preferable. The IV form is indicated for severe deficiencies. The skin-"whitening" effect at high doses is a separate topic.

Studies in PubMed

1. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. (Eur J Nutr, 2015)
2. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. (Eur J Clin Nutr, 2018)
3. Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial. (J Gerontol A Biol Sci Med Sci, 2023)
4. A Randomized Controlled Clinical Trial in Healthy Older Adults to Determine Efficacy of Glycine and N-Acetylcysteine Supplementation on Glutathione Redox Status and Oxidative Damage. (Front Aging, 2022)
5. Liposomal glutathione outperforms plain glutathione in uptake, cell regeneration and systemic availability: evidence from cellular and human models. (Br J Nutr, 2026)