glutathione is the only antioxidant your body produces that every other antioxidant depends on to function. let that sink in. vitamin C, vitamin E, alpha lipoic acid, CoQ10. every single one of them requires glutathione to recycle them back to their active form after they've neutralized a free radical. without glutathione they're single use. with glutathione they're infinite use. the one antioxidant nobody supplements is the one that makes all the others work your body produces glutathione from 3 amino acids: cysteine, glycine, and glutamate. the production declines by approximately 10% per decade after age 20. by age 60, you have roughly 60% of the glutathione you had at 20. every system that depends on antioxidant defense is operating at 60% capacity. the decline correlates precisely with the onset of every age related disease: cardiovascular disease, neurodegeneration, cancer, and metabolic dysfunction. the master antioxidant declines. the diseases follow the mechanism: glutathione is a tripeptide that donates electrons to reactive oxygen species (free radicals), neutralizing them before they damage DNA, mitochondria, and cell membranes. after donating its electron, glutathione is "spent" (oxidized form, GSSG). the body recycles GSSG back to active GSH using the enzyme glutathione reductase. the recycling is what makes it the "master": it regenerates itself AND regenerates every other antioxidant that becomes spent. remove glutathione and the entire antioxidant system collapses. that's it. one molecule. everything else depends on it - declines by approximately 10% per decade after age 20. the decline is the single best predictor of biological aging across all biomarkers studied - regenerates vitamin C, vitamin E, alpha lipoic acid, and CoQ10 after each neutralizes a free radical. without glutathione these antioxidants are one time use molecules. with it they recycle indefinitely - the liver depends on glutathione for phase 2 detoxification (the process that converts toxins into water soluble compounds for excretion). glutathione depletion means the liver cannot clear toxins efficiently. the "detox" industry sells cleanses. the body's actual detox system runs on glutathione - protects mitochondrial DNA from oxidative damage. mitochondrial DNA has no protective histone coating (unlike nuclear DNA). glutathione is the primary defense. when glutathione is low, mitochondrial DNA damage accelerates and the mitochondria produce less energy and more free radicals. a downward spiral - immune function depends critically on glutathione for T cell activation and proliferation. glutathione depleted individuals show reduced immune response across every metric measured. the difference between fighting off an infection in 2 days versus 7 days may be the glutathione level at the time of exposure - the brain has the second highest glutathione concentration of any organ (after the liver). glutathione depletion in the brain is now recognized as a hallmark of Parkinson's disease, Alzheimer's disease, and ALS. the neurodegeneration begins where the protection ends the supplement industry sells glutathione capsules that are mostly destroyed in the stomach (oral bioavailability of standard glutathione is under 5%). the industry knows this. the capsules are cheap to produce and the consumer doesn't know the absorption is negligible. the effective forms are: liposomal glutathione (encapsulated in lipid spheres that survive digestion, $30 to $50/month), or NAC (N acetyl cysteine, $10/month, which provides the rate limiting amino acid cysteine so your body can produce its own glutathione) take 600 to 1,200mg of NAC daily (the body converts it to glutathione internally, bypassing the absorption problem). or take 250 to 500mg of liposomal glutathione (Setria brand is the most studied). take on an empty stomach. combine with 1,000mg vitamin C and 200mg alpha lipoic acid to support the glutathione recycling system. effects on energy and recovery within 2 to 4 weeks. NOW Foods NAC: $10 for a 2 month supply every antioxidant you take depends on one molecule you've never supplemented. the molecule declines 10% per decade. at 60 you're running on 60%. the "anti aging" industry sells individual antioxidants that are single use without the master molecule that recycles them. $0.16 per day for NAC (which your body converts to glutathione) or $1 per day for liposomal glutathione delivered directly. the master antioxidant that every other antioxidant reports to costs less than a cup of coffee and is the one bottle missing from every supplement shelf.