glutathione side effects FAQ

Common side effects of Glutathione include:

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

Glutathione is an herbal supplement which can be used for treatment in male infertility (intramuscular use), plaque deposits in the arteries (atherosclerosis [intravenous, oral use]), cancers, chemotherapy adjunct (intramuscular, intravenous use), immunostimulant, liver diseases, lung diseases (inhaled use), memory loss, and Parkinson's disease (intravenous, oral use).

Schedule a comprehensive metabolic panel including ALT, AST, GGT, and bilirubin immediately. Elevated liver enzymes are asymptomatic in early stages. You won't feel hepatotoxicity until it's advanced. If ALT or AST are >1.5× upper limit of normal, reduce glutathione dose by 50% and retest in 4 weeks. Most glutathione-related enzyme elevations reverse within 8–12 weeks of dose reduction or cessation, but continued high-dose use in the presence of elevated markers increases the risk of hepatic fibrosis over time.

Taper dose by 25% every 2 weeks over a minimum 6-week period, and add 600mg N-acetylcysteine (NAC) daily during the taper to support endogenous glutathione synthesis. NAC provides cysteine. The rate-limiting amino acid for glutathione production. Without supplying preformed glutathione, allowing your gamma-glutamylcysteine synthetase expression to recover gradually. Monitor oxidative stress markers (urinary 8-OHdG or plasma MDA) at baseline, 4 weeks post-taper, and 12 weeks post-taper to confirm recovery trajectory.

Consider NK cell functional testing (available through specialty labs like LabCorp's ImmuKnow panel or Genova Diagnostics) if you've been on glutathione ≥18 months and have noticed increased infection frequency or slower recovery. NK suppression is dose- and duration-dependent. Cycling off glutathione for 8–12 weeks allows immune cell function to recover while maintaining most of the cumulative antioxidant benefits. Alternatively, switch to pulsed dosing: 1,000mg daily for 5 days, then 5 days off, which maintains intracellular glutathione elevation without chronic redox suppression.