Glutathione
The body's master antioxidant — a tripeptide of cysteine, glycine, and glutamate that every cell makes for itself. Levels fall with age, but the honest question is not whether glutathione matters; it is whether swallowing it does anything that supplying its precursors doesn't do better and cheaper.
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BiohackingHub Research TeamEditorial Research Team · Last updated: July 31, 2026
Medical Disclaimer: The information on this page is for educational and research purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.
What Is Glutathione?
Glutathione is a tripeptide — cysteine, glycine, glutamate — synthesised inside virtually every cell. It is the dominant intracellular antioxidant and the workhorse of phase II detoxification, the conjugation step where the liver tags fat-soluble toxins for excretion. Concentrations are highest in the liver, which is exactly where you would expect the body's chemical processing plant to keep its reagents.
Levels decline with age, and low glutathione tracks with oxidative stress and mitochondrial dysfunction across a large body of gerontology literature. That association is solid. What follows from it is where supplements get interesting.
Does Oral Glutathione Work?
The old objection was that glutathione is digested to its constituent amino acids before absorption, making supplementation pointless. That objection turned out to be too strong. A six-month randomised controlled trial found that oral glutathione raised body stores in blood, erythrocytes, and buccal cells at 250 and 1000 mg/day — a genuine, measured increase rather than a marketing claim.
So it works. The harder question is whether it works better than the alternative. The trials that produced the most impressive downstream outcomes — oxidative stress, mitochondrial function, inflammation, physical function in older adults — used precursors (glycine plus NAC), not intact glutathione. Precursor loading is also substantially cheaper.
Forms
| Form | Notes |
|---|---|
| Reduced (GSH) | The form used in the positive RCT; standard and inexpensive |
| Liposomal | Phospholipid encapsulation aims to protect the molecule through digestion; promising uptake data, thinner outcome data |
| S-acetyl | Acetylated for stability; mechanistically sensible, human evidence limited |
| Nebulised/IV | Clinical settings only — not a home intervention |
Dosage
| Parameter | Recommendation |
|---|---|
| Low | 250 mg/day |
| Typical | 500 mg/day |
| High | 1000 mg/day |
| Timing | Once daily; liposomal forms away from food |
| Alternative | NAC 1200 mg + glycine — better evidence per dollar |
Safety
Glutathione is what your cells already run on, and supplemental doses are well tolerated. There are no meaningful contraindications at these amounts; the caution worth flagging is for nebulised forms, which can provoke bronchospasm in asthmatics. Long-term high-dose data in healthy adults are still limited, which argues for staying near the studied range rather than escalating.
Related Research
Stacking Interactions
How Glutathione interacts with other compounds
Vitamin C regenerates oxidised glutathione back to the reduced form — the classic redox recycling pair
Glutathione peroxidases are selenoenzymes; without selenium, glutathione has fewer working enzymes to serve
Safety Profile — Tier A
Well-tolerated — strong human evidence
Contraindications
- ●No absolute contraindications at supplemental doses
- ●Asthma — caution with inhaled/nebulised forms, which can trigger bronchospasm
Side Effects
- ●Well tolerated orally; occasional bloating or loose stools
- ●Sulphurous taste or odour with some forms
- ●Long-term high-dose data in healthy adults remain limited