Glutathione
The body's master antioxidant. Most oral forms barely absorb — the trick is in the delivery (liposomal, S-acetyl, IV, or build it from precursors).
Strong evidence in fatty liver disease, oxidative stress reduction, and (for IV form) Parkinson's symptoms. GlyNAC trials show reversal of multiple biological-aging markers. Bad-delivery oral glutathione has yielded mixed results — when the form actually delivers, the effects are real. Effects: 4–8 weeks for oxidative markers; 16+ weeks for longevity markers.
Glutathione (GSH) is a tripeptide of glycine, cysteine, and glutamate that every cell makes and uses as its primary intracellular antioxidant. It neutralises free radicals, regenerates vitamins C and E, drives Phase II liver detoxification (conjugating toxins for excretion), and modulates immune function. Levels drop with age, illness, oxidative stress, and certain medications. Direct oral glutathione absorbs poorly (digestive enzymes break it apart), so most clinically-useful supplementation either uses advanced delivery forms (liposomal, S-acetyl) or supplies precursors (NAC, glycine) that let the body build its own.
- Form
- Liposomal glutathione — the most practical oral form; phospholipid encapsulation protects it through digestion. S-acetyl glutathione — also absorbs well, stable. NAC + glycine (GlyNAC) — the precursor approach, often more cost-effective. Sublingual / nebulised for specific use cases. IV glutathione for therapeutic doses. Plain reduced-GSH capsules are largely a waste.
- Dose
- Liposomal: 250–500 mg/day. S-acetyl: 100–300 mg/day. GlyNAC (precursor approach): 100 mg/kg/day each of glycine and NAC.
- Timing
- Empty stomach for liposomal (away from food for 20–30 min before/after). AM typical.
- Schedule
- Daily.
- Side effects
- Generally well-tolerated. Sulfur smell. Some report rash, asthma exacerbation (with inhaled form), or paradoxical fatigue.
- Interactions
- Chemotherapy (debated — may reduce efficacy of some agents). Generally clean.
- Contraindications
- Active asthma (caution with inhaled form). Pregnancy / lactation — limited data, default to caution.
- Lab markers
- Whole-blood glutathione (research-grade). GSH:GSSG ratio (reduced vs oxidised — better marker of redox status). 8-OHdG, F2-isoprostanes (oxidative stress markers).
- Food sources
- Asparagus, avocado, spinach, okra contain glutathione directly. Whey protein, eggs, garlic, onions, brassicas (broccoli, kale, Brussels sprouts) provide cysteine precursor. Cooking destroys most food glutathione.
Pairs with
NAC and glycine (precursors). Vitamin C and alpha-lipoic acid (regenerate oxidised glutathione). Selenium (cofactor for glutathione peroxidase, the enzyme that uses GSH). Milk thistle (additional liver support).
within Polyphenols & antioxidants