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Antioxidant

Glutathione (Reduced Form)

Also known as: L-glutathione, GSH, reduced glutathione, gamma-glutamylcysteinylglycine

C
Evidence

Reduced glutathione is a tripeptide antioxidant produced endogenously that plays a critical role in cellular detoxification and redox balance. Oral bioavailability is very limited due to degradation in the gastrointestinal tract, making supplementation efficacy questionable for systemic glutathione status.

Primary uses

  • Antioxidant support
  • Cellular detoxification
  • Immune function support
  • Oxidative stress reduction

How it works

  • Acts as a direct free radical scavenger and reduces oxidative stress
  • Cofactor for glutathione peroxidase and glutathione S-transferase enzymes
  • Supports cellular redox homeostasis
  • May enhance detoxification pathways

Dosage

Typical range
250-1500 mg daily
Timing
Morning on empty stomach may improve absorption slightly
With food
With food may reduce absorption; optimal timing unclear due to low bioavailability
Duration
Ongoing use is typical for those seeking antioxidant support; no established maximum duration
Special populations
Pregnant/nursing women should consult healthcare provider; those with severe liver disease should use cautiously

Forms

  • Powder· 70/100
  • Capsule· 70/100
  • Liposomal· 70/100
  • Sublingual· 70/100

Safety

Common side effects

  • Generally well-tolerated at typical doses
  • Mild nausea or abdominal discomfort (rare)
  • Headache (rare)

Contraindications

  • High doses may theoretically interact with chemotherapy or radiation therapy
  • Caution in individuals with cystinuria

Evidence notes

While glutathione's biological role is well-established, oral supplementation has limited evidence for systemic bioavailability and clinical efficacy. Most studies using glutathione were IV or inhaled; oral studies show minimal absorption. Grade C reflects preliminary evidence for oral form specifically.

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.