Glutathione Oral Overdose Management
Glutathione oral overdose does not require specific treatment because oral glutathione has negligible systemic bioavailability and is not absorbed intact from the gastrointestinal tract. 1
Why No Treatment is Necessary
Oral glutathione is essentially non-toxic due to poor absorption:
- A clinical study in healthy volunteers demonstrated that even after administration of 3 grams of oral glutathione (0.15 mmol/kg), plasma glutathione concentrations did not increase significantly over 270 minutes 1
- The systemic availability of oral glutathione is negligible in humans because intestinal and hepatic gamma-glutamyltransferase rapidly hydrolyze glutathione before it reaches systemic circulation 1
- Dietary glutathione is not a major determinant of circulating glutathione levels, making it impossible to increase circulating glutathione to clinically significant levels through oral administration 1
Supportive Care Only
If a patient presents after ingesting large amounts of oral glutathione, provide only supportive care:
- Monitor for gastrointestinal symptoms (nausea, vomiting, abdominal discomfort) which would be the only expected effects from large oral doses 1
- No specific antidote or decontamination procedures are indicated 1
- Reassure the patient that systemic toxicity is not expected due to the lack of absorption 1
Important Distinction from Intravenous Glutathione
This guidance applies only to oral overdose - intravenous glutathione has different pharmacokinetics:
- Intravenous glutathione bypasses first-pass metabolism and achieves therapeutic blood levels 2
- Clinical trials using intravenous glutathione at doses of 1,500-5,000 mg have been conducted safely in cancer patients receiving chemotherapy 3
- However, these studies involved controlled medical administration, not overdose scenarios 3
Clinical Context
Glutathione's poor oral bioavailability is well-established: