Quantitative determination of reduced glutathione (GSH) and oxidised glutathione (GSSG) with calculated redox ratio. Performed by LC-MS/MS from DBS or EDTA whole blood.
2 analytes + ratio
3–5 working days
This method assesses the cellular redox state by measuring both reduced and oxidised forms of glutathione, the body's most abundant intracellular antioxidant.
Clinical indications include:
| Analyte / Group | Components | Clinical Significance |
|---|---|---|
| GSH | Reduced glutathione | Active antioxidant form; neutralises reactive oxygen species and supports detoxification |
| GSSG | Glutathione disulfide (oxidised) | Formed when GSH neutralises free radicals; elevated levels indicate oxidative stress |
| GSH:GSSG ratio | Redox ratio | Primary indicator of cellular redox state; a lower ratio indicates greater oxidative stress |
Glutathione is a tripeptide (glutamate-cysteine-glycine) and the most abundant intracellular antioxidant in the human body. It plays a central role in protecting cells from oxidative damage, detoxifying xenobiotics, and maintaining the redox state of other antioxidants including vitamins C and E.
The body's master antioxidant and detoxification molecule
Ratio reflects real-time cellular oxidative stress
Composed of glutamate, cysteine, and glycine
The ratio of reduced to oxidised glutathione (GSH:GSSG) is one of the most reliable indicators of cellular oxidative stress. Under normal conditions, more than 90% of total glutathione exists in the reduced (GSH) form. A shift toward the oxidised form (GSSG) indicates that the cell's antioxidant capacity is being overwhelmed by reactive oxygen species.
Glutathione depletion has been implicated in a wide range of conditions including neurodegenerative diseases (Parkinson's, Alzheimer's), liver disease, chronic fatigue, autoimmune disorders, and accelerated ageing. It also plays a critical role in phase II hepatic detoxification, conjugating with toxins and drugs to facilitate their excretion.
The test employs isotope-dilution LC-MS/MS with rapid derivatisation to stabilise the labile thiol groups and prevent ex vivo oxidation. This ensures accurate measurement of the true in vivo GSH:GSSG ratio, which is critical for meaningful clinical interpretation.
Available from DBS or EDTA whole blood. Immediate sample stabilisation during collection is essential to prevent artefactual oxidation of GSH to GSSG, which would falsely elevate the oxidative stress reading.
From enquiry to results in a few simple steps — no clinic visit required.
This test is available to healthcare professionals, wellness brands, clinics, and research institutions worldwide. We currently serve partners in:
Whether you need testing services for your patients, white-label kits for your brand, or method transfer to your own laboratory — get in touch to discuss how we can work together.
The glutathione index measures the ratio of reduced glutathione (GSH) to oxidised glutathione (GSSG) in your blood. GSH is your body's most abundant intracellular antioxidant — it protects cells from oxidative damage, supports detoxification, and recycles other antioxidants like vitamins C and E. The GSH:GSSG ratio is one of the most reliable indicators of how well your cells are handling oxidative stress.
Glutathione levels decline naturally with age and can be depleted by chronic illness, medications (particularly paracetamol and chemotherapy), alcohol, environmental toxins, and poor diet. Low glutathione has been linked to neurodegenerative diseases, liver dysfunction, chronic fatigue, and accelerated ageing. Testing gives you an objective measurement rather than guessing — and it allows you to track whether interventions like NAC supplementation are actually working.
The test uses a simple finger-prick to collect a few drops of blood onto a dried blood spot (DBS) card. You can do this at home or in a clinic — no venous blood draw is needed. The DBS card is stable at room temperature and can be posted to our laboratory by regular mail from anywhere in the world.
Results are typically delivered within 3 to 5 working days from the time your sample arrives at our laboratory. The analysis is performed by LC-MS/MS (liquid chromatography-tandem mass spectrometry), which provides highly accurate and specific quantification of both GSH and GSSG.
A low GSH:GSSG ratio indicates that your cells are under significant oxidative stress — more glutathione is being oxidised than your body can regenerate. This can be caused by chronic inflammation, infection, toxin exposure, nutrient deficiencies (particularly cysteine, glycine, and selenium), or high metabolic demand. Your healthcare provider can use this result alongside clinical context to guide interventions such as NAC supplementation, dietary changes, or further investigation.
Masdiag's glutathione index test is available worldwide through our partner network. We currently serve healthcare professionals, wellness brands, and clinics in Europe, the United Kingdom, Asia, Australia, New Zealand, and the United States. Contact us to discuss testing services, white-label kits, or method transfer to your laboratory.
Whether you need testing services, method transfer, or white-label kit development — we'd love to hear from you.