Glutathione
Master Antioxidant | Tripeptide | GSH
Glutathione (GSH) is a tripeptide composed of glutamate, cysteine, and glycine, often called the body's 'master antioxidant.' Found in virtually every cell, it plays critical roles in neutralizing free radicals, detoxifying harmful substances, recycling other antioxidants (vitamins C and E), and supporting immune function. Glutathione levels decline with age and are depleted by stress, toxins, and certain diseases. Injectable forms bypass poor oral bioavailability to deliver glutathione directly to tissues.
Daily dose
200-600 mg (injectable)
Frequency
1-3x per week
Cycle length
4-8 weeks
Storage
Refrigerated (2-8°C)
Key benefits
Master antioxidant neutralizing free radicals. Essential for liver detoxification (Phase II conjugation). Supports immune function and T-cell activity. Recycles vitamins C and E.
How it works
Glutathione's sulfhydryl group donates electrons to neutralize reactive oxygen species. Conjugates toxins via glutathione S-transferase for excretion. Essential for lymphocyte proliferation and optimal immune response. The unique gamma peptide bond resists degradation by peptidases.
Dosage protocols
Goal
General support
Dose
200-400 mg · 1-2x weekly
Route
IM or IV
Goal
Detoxification
Dose
400-600 mg · 2-3x weekly
Route
IV
Goal
Neurological (research)
Dose
1400 mg · 3x weekly
Route
IV infusion
Research indications
antioxidant Support
detoxification
immune Function
neurological Health
Administration
Safety notes
Generally well-tolerated
Injection site stinging/pain common if pH not properly buffered (should be pH 6.0-7.0)
IV carries anaphylaxis risk - clinical supervision recommended
Avoid during chemotherapy without oncologist approval
May worsen asthma symptoms
Avoid in pregnancy/breastfeeding - safety not established
Long-term high-dose use may deplete zinc
Research studies
High-dose IV Glutathione Pharmacokinetics - Aebi et al.
Human | 2g/m² IV infusion | Rapid clearance | t½ ~14 minutes
Classic pharmacokinetic study demonstrating that IV glutathione significantly increases plasma levels but has a short half-life (~14 minutes), with rapid conversion to cysteine and other metabolites.
View study →Glutathione in Parkinson's Disease - Substantia Nigra Depletion
Human | Post-mortem | 40% reduction in substantia nigra
Landmark study showing GSH levels were reduced by 40% in the substantia nigra of Parkinson's patients compared to controls, establishing the oxidative stress connection in PD pathogenesis.
View study →Intranasal Glutathione Phase IIb Trial - Mischley et al.
Human | 45 PD patients | 3 months | Intranasal GSH
Double-blind, placebo-controlled trial found intranasal glutathione increased brain GSH levels and showed mild motor improvement in Parkinson's patients, though placebo group also improved.
View study →Glutathione for Skin Lightening - Systematic Review (2025)
Review | Multiple RCTs | Oral, IV, topical forms
Comprehensive review found limited evidence supporting glutathione for skin lightening. Oral and topical forms showed modest effects in some trials, while IV carries safety concerns including hepatotoxicity.
View study →Glutathione and Immune Function - Droge & Breitkreutz
Review | Lymphocyte function | GSH depletion effects
Demonstrated that even moderate changes in intracellular glutathione have profound effects on lymphocyte function, including T-cell proliferation and NK cell activity.
View study →GSH in Liver Detoxification - Phase II Conjugation
Review | Hepatic metabolism | Xenobiotic detoxification
Established glutathione's central role in Phase II liver detoxification, conjugating toxins and drugs to water-soluble forms for excretion via bile and urine.
View study →