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Antioxidant

L-Glutathione Reduced

Also known as: Reduced Glutathione, GSH, L-γ-Glutamyl-L-cysteinyl-glycine, Glutathione (reduced form)

C
Evidence

L-Glutathione is a tripeptide antioxidant naturally produced in cells that helps neutralize free radicals and support detoxification processes. Oral bioavailability is limited due to rapid degradation in the digestive tract, though some studies suggest reduced forms may be better absorbed than oxidized forms.

Primary uses

  • Antioxidant support
  • Cellular detoxification
  • Immune function support
  • Liver health
  • Detoxification support
  • Cellular health
  • Oxidative stress reduction

How it works

  • Direct antioxidant activity via conjugation with free radicals and oxidative species
  • Cofactor for glutathione peroxidase and glutathione S-transferase enzymes
  • Regeneration of other antioxidants (vitamins C and E)
  • Protein synthesis and DNA repair support

Dosage

Typical range
250–1000 mg daily
Timing
Any time of day; with or without food
With food
No strong preference; some sources suggest taking with vitamin C to enhance absorption
Duration
Safety data supports continuous use; optimal duration for therapeutic benefit unclear
Special populations
Pregnant/nursing women should consult practitioners; limited safety data in pediatric populations

Forms

  • Powder· 70/100
  • Capsule· 70/100
  • Tablet· 70/100
  • Liposomal· 70/100
  • S-Acetyl Glutathione· 70/100
  • Sublingual· 70/100

Safety

Common side effects

  • Generally well tolerated at typical doses
  • Rare: mild gastrointestinal upset
  • Rare: headache or skin reactions

Contraindications

  • Avoid in individuals taking cisplatin or other chemotherapies (may reduce efficacy)
  • Caution in patients with cystinuria or homocystinuria
  • Limited data in pregnancy—consult healthcare provider

Evidence notes

Oral glutathione has limited bioavailability; most human studies show modest systemic absorption. Some evidence supports IV forms in clinical settings, but oral supplementation evidence is preliminary. Well-established physiological importance does not translate to strong oral supplement efficacy data.

Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.

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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider.