Glutathione
Also known as: GSH, Reduced glutathione
Randomized trials in healthy and clinical populations indicate that oral glutathione (commonly 250–1,000 mg/day) can increase circulating and cellular glutathione measures and lower some oxidative stress markers; clinical outcome data are limited and mixed across conditions.
Last reviewed: 2026-10-14 · 5 indexed studies
Set your location for accurate regulatory status
Saved on this device — no sign-in needed.
Overview
Glutathione (reduced form, GSH) is the body’s principal intracellular antioxidant and is sold as an oral supplement. Human trials show that daily oral GSH can raise blood and tissue glutathione measures over weeks to months, with some reported effects on oxidative markers, immunity and the gut microbiome.
Mechanism & Function
Mechanism of Action
Directly supplies reduced glutathione to body compartments or supports circulating glutathione pools, which can lower oxidant:antioxidant ratios and potentially modulate immune and inflammatory signalling.
Physiological Role
Primary intracellular antioxidant; participates in redox buffering, detoxification reactions, and maintenance of thiol status in proteins and cells.
Primary Pathways
Performance / Health Relevance
By increasing cellular glutathione and lowering oxidant markers, oral GSH could plausibly support recovery from oxidative stress and influence immune or metabolic parameters, but direct performance effects are not established in the provided trials.
Evidence Review
Practical Use & Dosage
- Minimum Effective Dose
- 250 mg/day (reported increases in some compartments)
- Optimal Range
- 500–1,000 mg/day (commonly used in trials showing larger effects)
- Upper / Caution Level
- Not established
- Timing
- Once daily in the trials provided
- Best Format
- Oral reduced glutathione (capsule/tablet) as used in trials
- Bioavailability
- Human trials report increases in blood and tissue glutathione with oral dosing, but bioavailability may be dose- and time-dependent.
- Absorption Considerations
- Increases were dose- and time-dependent in trials and reversed after washout; specific absorption enhancers were not described in the provided abstracts.
Safety & Interactions
Side Effects
- •No adverse reactions reported in the provided trials; comprehensive safety data limited in abstracts
Contraindications
- Not established from provided trials
Drug Interactions
- •Not established from provided trials
Who Should Avoid
- •Insufficient data in pregnancy and breastfeeding; caution advised in these groups
Monitoring
If used long term, monitoring of clinical response and routine safety as per healthcare professional guidance is prudent; trials measured glutathione and oxidative markers.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Glutathione typically used or indicated?
Glutathione is most commonly used for: Antioxidant support, Support for glutathione body stores, Adjunctive metabolic support (research). Primary intracellular antioxidant; participates in redox buffering, detoxification reactions, and maintenance of thiol status in proteins and cells.
How does Glutathione work?
Directly supplies reduced glutathione to body compartments or supports circulating glutathione pools, which can lower oxidant:antioxidant ratios and potentially modulate immune and inflammatory signalling.
What is the recommended dose of Glutathione?
The optimal range is 500–1,000 mg/day (commonly used in trials showing larger effects). with a minimum effective dose of 250 mg/day (reported increases in some compartments). Best taken: Once daily in the trials provided. Upper / caution level: Not established.
What are the side effects of Glutathione?
Reported side effects include: No adverse reactions reported in the provided trials; comprehensive safety data limited in abstracts. Monitoring: If used long term, monitoring of clinical response and routine safety as per healthcare professional guidance is prudent; trials measured glutathione and oxidative markers.
Does Glutathione interact with medications?
Known or theoretical interactions: Not established from provided trials. Always check with a clinician before combining with prescription medication.
Who should avoid Glutathione?
Glutathione is generally not recommended for: Insufficient data in pregnancy and breastfeeding; caution advised in these groups; and Not established from provided trials.
How strong is the evidence for Glutathione?
Evidence level: Moderate (overall score 59/100), based on 5 indexed studies on SuppIndex.
Research & References (5)
Randomized controlled trial of oral glutathione supplementation on body stores of glutathione.
6-month randomized, double-blind, placebo-controlled trial in 54 healthy non-smoking adults comparing oral glutathione 250 mg/day and 1,000 mg/day versus placebo, with measures in blood, erythrocytes, plasma, lymphocytes and buccal cells.
Effect of long-term oral glutathione supplementation on gut microbiome of type 2 diabetic individuals.
Randomized clinical trial in individuals with type 2 diabetes given 500 mg oral GSH once daily for 6 months; gut microbiome analysed by 16S rRNA sequencing and prior work from the trial reported increased body glutathione and stabilised HbA1c.
A clinical trial of glutathione supplementation in autism spectrum disorders.
Eight-week, open-label trial in children with autism spectrum disorder comparing oral lipoceutical glutathione and transdermal glutathione; the oral group showed changes in plasma metabolites.
Antioxidant supplementation for lung disease in cystic fibrosis.
Cochrane review of antioxidants in cystic fibrosis including studies of oral and inhaled supplements; among included trials was an oral glutathione study but overall evidence across antioxidants was heterogeneous.
Effectiveness of oral glutathione in reducing nitric oxide and IL-1α concentrations for clinical improvement in mild to moderate acne vulgaris: a randomized controlled trial.
Randomized controlled trial in 40 subjects with mild to moderate acne given 500 mg oral glutathione or placebo once daily for 4 weeks, measuring serum nitric oxide, IL-1α and clinical severity.
Related Ingredients
Other top-rated ingredients in Amino Acids.
L-Leucine
82/100Essential BCAA that activates mTORC1 via Sestrin2 sensing, driving phosphorylation of S6K1 and 4E-BP1, initiating cap-dependent translation and muscle protein synthesis.
Beta-Alanine
78/100A rate-limiting precursor to carnosine (β-alanyl-L-histidine) synthesis, enhancing intramuscular pH buffering capacity during high-intensity anaerobic exercise.
EAA Blend
78/100Free-form blend of 9 EAAs (Leu, Ile, Val, Lys, Met, Phe, Thr, Trp, His) at evidence-based ratios; bypasses gastric digestion for rapid plasma aminoacidaemia.
Research Overview
Moderate EvidenceCite this ingredient
One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.
Stable URL
https://thesuppindex.com/ingredients/glutathione
SuppIndex. (2026). Glutathione: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/glutathione
Based on 5 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
No direct interaction data provided; glutathione may be combined with other antioxidant nutrients in research settings.