What are the indications and dosing recommendations for glutathione (Glutathione) supplementation?

Glutathione Supplementation: Indications and Dosing Recommendations

There is insufficient consistent clinical evidence to recommend glutathione supplementation for most clinical conditions, with limited specific indications supported by current guidelines.

Established Clinical Indications

• Currently, there are no strong clinical guideline recommendations supporting routine glutathione supplementation for most medical conditions 1
• In patients undergoing hematopoietic stem cell transplantation (HSCT), parenteral glutamine supplementation may be beneficial at a dose of approximately 0.6 g/kg/day 1
• For patients with cystic fibrosis, guidelines specifically state there are no data supporting the use of glutathione therapy 1

Potential Applications Based on Limited Evidence

• Oral glutathione supplementation has shown promise in:
  • Increasing body stores of glutathione by 30-35% in erythrocytes, plasma, and lymphocytes at doses of 1000 mg/day over 6 months 2
  • Improving insulin sensitivity in obese individuals with and without type 2 diabetes at doses of 1000 mg/day for 3 weeks 3
  • Enhancing immune function markers, including Natural Killer cell cytotoxicity (up to 400% increase) and lymphocyte proliferation (up to 60% increase) at doses of 500-1000 mg/day 4

Parenteral Glutamine Supplementation

• For surgical patients who cannot be fed adequately enterally and require exclusive parenteral nutrition (PN), parenteral glutamine supplementation may be considered, though evidence is not strong 1
• Standard dosage for parenteral glutamine in surgical patients has been studied at 0.35 g/kg body weight 1
• In HSCT patients, glutamine administration has been reported to:
  • Minimize intestinal mucosal atrophy associated with exclusive PN 1
  • Reduce liver damage caused by chemotherapy or radiotherapy 1
  • Potentially improve nitrogen balance, immune system function, and reduce infection risk 1

Important Cautions and Contraindications

• High-dose glutamine supplementation has been associated with increased mortality in critically ill patients with multi-organ failure 5
• In patients with acute kidney injury or chronic kidney disease with kidney failure, high-dose parenteral glutamine should not be administered 1
• Patients with severe liver or kidney disease should use glutamine with caution due to its role in ammonia metabolism 5

Dosing Considerations

• For parenteral administration in surgical or HSCT patients: 0.35-0.6 g/kg/day 1
• For oral supplementation in non-critically ill patients: 500-1000 mg/day has been studied with measurable effects on glutathione levels 4, 2
• Liposomal glutathione formulations may provide better bioavailability than standard oral formulations 4

Monitoring Recommendations

• No specific monitoring parameters are required for glutathione supplementation in most patients 5
• Standard clinical follow-up to assess symptom changes and potential side effects is prudent 5
• Patients should be advised to report any unusual symptoms 5

Limitations of Current Evidence

• Most studies on oral glutathione supplementation have small sample sizes 4, 2, 3
• Long-term safety and efficacy data are limited 6
• The relationship between glutathione supplementation and clinical outcomes in chronic diseases requires further investigation in larger trials 6