Antioxidant
Glutathione (Reduced Form)
Also known as: L-glutathione, GSH, reduced glutathione, gamma-glutamylcysteinylglycine
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
Products containing Glutathione (Reduced Form)
Top-scoring supplements in our catalog that list Glutathione (Reduced Form) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
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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