Is 10,000 milligrams (mg) of glutathione per day an excessive dose?

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Last updated: October 16, 2025View editorial policy

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10,000 mg of Glutathione is Excessive and Potentially Unsafe

A daily dose of 10,000 mg (10 grams) of glutathione is excessive and not recommended based on available evidence. The safety and efficacy data for glutathione supplementation does not support such high dosages.

Safe and Effective Dosing of Glutathione

  • Clinical studies have shown that much lower doses of glutathione are effective for increasing body stores of glutathione. Research demonstrates that 250-1,000 mg/day is sufficient to increase glutathione levels in blood, erythrocytes, plasma, and lymphocytes 1.

  • At 1,000 mg/day (the higher dose in clinical trials), glutathione levels increased 30-35% in erythrocytes, plasma, and lymphocytes after 6 months of supplementation 1.

  • Even at these much lower doses (250-1,000 mg/day), the increases in glutathione levels were dose and time dependent, suggesting that higher doses may not be necessary 1.

Safety Concerns with High-Dose Glutathione

  • Safety assessments for S-Acetyl Glutathione (a bioavailable form of glutathione) established a No Observed Adverse Effect Level (NOAEL) of 1,500 mg/kg/day in animal studies, but this doesn't support using 10,000 mg in humans 2.

  • There are no clinical studies supporting the safety of 10,000 mg daily glutathione supplementation in humans.

  • For comparison, vitamin D supplementation guidelines suggest that even doses up to 10,000 IU per day over several months are considered safe 3, but this principle cannot be extrapolated to glutathione which has a different safety profile.

Clinical Applications of Glutathione at Lower Doses

  • For skin-lightening effects, studies have used oral glutathione at much lower doses of 250 mg once daily, 250 mg twice daily, or 500 mg once daily 4.

  • In studies examining glutathione's effects on insulin sensitivity in obese subjects with and without type 2 diabetes, 1,000 mg/day was used successfully 5.

  • For neurological conditions like Parkinson's disease, intravenous glutathione has been studied at doses of 1,400 mg administered three times weekly, not daily 6.

Potential Risks of Excessive Glutathione

  • There are no guidelines supporting the use of glutathione therapy at 10,000 mg daily for any condition 3.

  • High doses of supplements can potentially disrupt the body's natural regulatory mechanisms and may lead to unexpected adverse effects.

  • While glutathione is an important endogenous antioxidant, excessive supplementation could potentially disrupt the body's redox balance.

Recommendation

  • If glutathione supplementation is desired, start with evidence-based doses of 250-1,000 mg/day, which have been shown to effectively increase body stores of glutathione 1.

  • Monitor for any adverse effects, even at these lower doses, as individual responses may vary.

  • Consider the specific health condition being addressed, as different conditions may require different approaches to antioxidant therapy.

References

Research

Safety assessment of S-Acetyl Glutathione for use in foods and dietary supplements.

Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial.

Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme, 2021

Research

Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease.

Movement disorders : official journal of the Movement Disorder Society, 2009

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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