Glutathione: benefits, dosage, contraindications
Other name(s)
GSH
Scientific name(s)
L-Glutathione
Family or group:
Pseudovitamin(s)
Indications
Scoring methodology
EFSA approval.
Chemotherapy ✪✪✪✪✪
Glutathione protects cells against the toxicity of chemotherapy. A dose of 1.5 to 3 g/m² was administered by slow intravenous infusion over 15 to 20 minutes, immediately before chemotherapy. rnrn
Posologie
Oral
1.5 - 3 g/m²
A pilot clinical trial of postoperative intensive weekly chemotherapy using cisplatin, epi-doxorubicin, 5-fluorouracil, 6S-leucovorin, glutathione and filgrastim in patients with resected gastric cancer.
A phase II study of combination chemotherapy in advanced ovarian carcinoma with cisplatin and cyclophosphamide plus reduced glutathione as potential protective agent against cisplatin toxicity.
High-dose cisplatin and cyclophosphamide with glutathione in the treatment of advanced ovarian cancer.
A randomised double-blind placebo controlled clinical trial assessing the tolerability and efficacy of glutathione as an adjuvant to escalating doses of cisplatin in the treatment of advanced ovarian cancer.
Phase I trial of cisplatin in combination with glutathione.
Intensive weekly chemotherapy is not effective in advanced pancreatic cancer patients: a report from the Italian Group for the Study of Digestive Tract Cancer (GISCAD).
Influence of glutathione administration on the disposition of free and total platinum in patients after administration of cisplatin.
Intensive weekly chemotherapy for advanced gastric cancer using fluorouracil, cisplatin, epi-doxorubicin, 6S-leucovorin, glutathione, and filgrastim: a report from the Italian Group for the Study of Digestive Tract Cancer.
Glutathione reduces the toxicity and improves quality of life of women diagnosed with ovarian cancer treated with cisplatin: results of a double-blind, randomized trial.
Neuroprotective effect of reduced glutathione on cisplatin-based chemotherapy in advanced gastric cancer: a randomized double-blind placebo-controlled trial.
Skin lightening ✪✪✪✪✪
Clinical studies show that daily intake of 500 mg of glutathione in combination with selenium, vitamin C, vitamin D3, vitamin E, and grape seed extract has a skin-lightening effect in women with brown or dark brown skin, compared with their initial skin color.rnrn
Posologie
Oral
600 - 1200 mg
Synergies
An open-label, single-arm trial of the safety and efficacy of a novel preparation of glutathione as a skin-lightening agent in Filipino women.
The Clinical Effect of Glutathione on Skin Color and Other Related Skin Conditions: A Systematic Review
Oxidative stress ✪✪✪✪✪
Glutathione (GSH) is the main endogenous intracellular antioxidant. It has many functions, including protecting cells against oxidative stress, detoxifying toxins and carcinogens, and maintaining immune function. rnrnAlmost all body tissues synthesize GSH by the sequential addition of the precursor amino acids cysteine, glutamic acid, and glycine, through enzymatic catalysis by two ATP-dependent enzymes, glutamate–cysteine ligase (GCL) and GSH synthetase (GS). Maintaining tissue GSH levels is essential for preserving health, preventing disease, and resisting age-related biological insults. Low GSH levels are associated with an increased risk of many diseases, including cancer, cardiovascular disease, arthritis, and diabetes.rnrnGSH levels depend on the availability of its precursor amino acids—cysteine, glutamic acid, and glycine—with cysteine most often considered the limiting factor. Oral GSH supplementation is one strategy to increase GSH levels in tissues. There are few data on GSH bioavailability in humans, although GSH has been observed to be absorbed and transported in human intestinal epithelial cells in vitro and in oral mucosal cells in vivo. A randomized, double-blind clinical study conducted in healthy subjects showed that GSH supplementation increases GSH stores in the human body.rnrn
Posologie
Oral administration
250 - 1000 mg
Sports performance ✪✪✪✪✪
A small clinical study shows that taking 200 mg of glutathione in combination with 2 grams of L-citrulline per day for 4 weeks increased lean mass after 4 weeks of resistance training and was positively associated with muscle strength. However, after 8 weeks of resistance training, there were no significant differences in any of the measured variables.rnrn
Posologie
Oral
200 mg
Synergies
Liver disorders ✪✪✪✪✪
Preliminary clinical research shows that taking 300 mg of glutathione per day for 4 months reduces alanine aminotransferase (ALT) levels by about 13% and triglyceride levels by about 16% but has no impact on aspartate aminotransferase (AST) levels or liver stiffness, compared with baseline values in patients with NAFLD. The validity of these results is limited by the absence of a comparison group.rnrn
Posologie
Oral
300 mg
Immune support ✪✪✪✪✪
Glutathione contributes to strengthening the body's defenses by stimulating the production of lymphocytes or interleukins of the immune system.rnrn
Posologie
Oral
300 mg
Lymphocyte glutathione levels in children with cystic fibrosis
In vitro glutathione supplementation enhances interleukin-2 production and mitogenic response of peripheral blood mononuclear cells from young and old subjects
Glutathione deficiency is associated with impaired survival in HIV disease
Properties
Antioxidant
Glutathione is a tripeptide known as the most important non-enzymatic antioxidant in the human body. Indeed, glutathione is present both in a reduced form known as reduced glutathione (GSH) before exerting antioxidant effects and in an oxidized form (GSSG) after exerting antioxidant effects. GSH and GSSG form a ratio known as the GSH/GSSG ratio, changes in which indicate shifts in cellular oxidative balance. Glutathione is used as a substrate by antioxidant enzymes known as glutathione S-transferases (GSTs). On the other hand, another group of enzymes called glutathione peroxidases (GPx) use glutathione tripeptides to reduce lipid peroxidation and convert hydrogen peroxide into water.
Usages associés
Neurological
Glutathione is synthesized by neurons and glial cells. In vitro, it has been suggested that glutathione protects against toxins by acting as an antioxidant. In addition, there is evidence linking decreased glutathione to Parkinson's disease. However, it is not known whether reduced glutathione levels result from increased oxidative stress, which is associated with the pathogenesis of Parkinson's disease, or whether glutathione depletion itself actually contributes to the pathogenesis of Parkinson's disease. Other evidence shows that glutathione deficiency may potentiate inflammation associated with Parkinson's disease by increasing the production and activity of inflammatory cytokines. Therefore, theoretically, glutathione supplementation may attenuate inflammation associated with Parkinson's disease.
Dermatologic effect
Glutathione supplements are commonly used with the aim of lightening the complexion for aesthetic purposes. There are various proposed mechanisms explaining this effect, mainly revolving around glutathione's interactions with tyrosinase, an enzyme involved in melanin synthesis. These proposed mechanisms include interference with the cellular transfer of tyrosinase to melanosomes (an intracellular organelle within which melanins are produced), causing increased synthesis of pheomelanin and decreased synthesis of eumelanin (these are two components of biological melanin; pheomelanin is lighter in color than eumelanin, yellow to red, its UV absorption capacity is lower than that of eumelanin and therefore it offers less protection from UV-induced damage). Another proposed mechanism is the removal of peroxides generated by ultraviolet radiation, which induce tyrosinase activity.
Usages associés
Anticancer
Preliminary data suggest that glutathione intake from fruits and vegetables may be associated with a reduced risk of pharyngeal cancer. rnrn
Antiviral
Glutathione can inhibit the activity of enzymes that help the influenza virus colonize the cells that line the mouth and throat. Mice infected with influenza and given drinking water enriched with glutathione have lower tissue viral levels than untreated mice. Human studies are needed to determine the effects of glutathione on influenza infection.rnrn
Safe dosage
Adult: 200 mg
Afssa considers that the body of available publications does not provide a sufficient basis to justify glutathione supplementation for a healthy person consuming a varied, balanced diet with a caloric intake sufficient to meet their needs. However, Afssa considers that there is no scientific evidence opposing an additional intake (including dietary supplements and fortification) of glutathione at the dosernrnof 50 mg/day proposed by the DGCCRF (Directorate General for Competition, Consumer Affairs, and Fraud Control).rnrn
Precautions
Pregnant women: avoid
Avoid use due to lack of reliable and sufficient information.rnrn
Asthma: use with caution
Inhaled glutathione can cause bronchospasm in people with asthma.rnrn
Breastfeeding women: avoid
Avoid use due to lack of reliable and sufficient information.rnrn
