Glutathione in clinical assessment
Glutathione (GSH) is the most abundant intracellular antioxidant in the human body and plays a central role in detoxification, immune regulation, and cellular redox balance. For clinicians, measuring glutathione status provides a direct window into a patient's oxidative stress burden — an underlying factor in conditions ranging from chronic fatigue and neurodegeneration to liver disease and accelerated ageing.
Unlike indirect oxidative stress markers, glutathione measurement quantifies the body's actual antioxidant reserve capacity. The ratio of reduced glutathione (GSH) to oxidised glutathione (GSSG) is particularly informative, as a shift toward GSSG indicates that antioxidant defences are being overwhelmed.
Clinical populations where testing adds value
Glutathione testing is particularly informative in patients with chronic liver disease (glutathione is synthesised primarily in the liver and is essential for hepatic detoxification), neurodegenerative conditions such as Parkinson's disease (where substantia nigra glutathione depletion is a consistent finding), HIV/AIDS (where glutathione deficiency correlates with disease progression), chronic obstructive pulmonary disease, patients undergoing chemotherapy, and individuals with high environmental toxin exposure.
In integrative and functional medicine settings, glutathione testing helps guide decisions about N-acetylcysteine (NAC) supplementation, liposomal glutathione, or IV glutathione therapy — providing objective pre- and post-treatment measurements rather than empirical dosing.
Interpreting the Glutathione Index
Masdiag's Glutathione Index measures both GSH and GSSG from a dried blood spot using LC-MS/MS, and reports the GSH:GSSG ratio alongside absolute values. A declining ratio (more oxidised relative to reduced glutathione) is an early indicator of oxidative stress that may precede clinical symptoms. Serial monitoring is valuable in tracking treatment response and disease progression in at-risk patients.
Glutathione and ageing
Age-related decline in glutathione levels is well documented and is thought to contribute to the increased oxidative damage, mitochondrial dysfunction, and immune senescence observed in older adults. Some researchers consider glutathione status a potential biomarker of biological (as opposed to chronological) age. For longevity-focused clinicians, glutathione monitoring provides an objective marker to track the efficacy of antioxidant-support interventions over time.
Frequently asked questions
What causes low glutathione levels?
Glutathione depletion can result from chronic illness, ageing, poor nutrition (particularly low intake of cysteine, glycine, and glutamic acid), excessive alcohol consumption, environmental toxin exposure, and certain medications. Chronic oxidative stress from any cause will deplete glutathione reserves over time.
Can you raise glutathione levels through diet or supplements?
Yes. N-acetylcysteine (NAC) is the most evidence-based oral supplement for boosting glutathione synthesis. Liposomal glutathione and IV glutathione are also used clinically. Dietary sources rich in sulfur-containing amino acids (whey protein, cruciferous vegetables, garlic) support endogenous production. Testing before and after intervention confirms efficacy.
Explore This Test
View method details, sample requirements, and reporting for our Glutathione Index.
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