Glutathione is an antioxidant that maintains the homeostasis of oxidation-reduction (redox) in cells. Reduced glutathione (GSH) is found in almost every standard cell at high concentrations.
Glutathione is essential against reactive oxygen species (ROS). It is important to keep redox balances of the cells, cell cycle regulation, apoptosis, immunological defense, and pathological abnormalities (1, 2). As we can see, glutathione participates in a wide range of biological and biochemical processes, and its deficiency can increase oxidative stress.
Stress conditions caused by glutathione deficiency can lead to various diseases, such as:
- Inflammation,
- Virus infection,
- Sickle cell anemia,
- Cancer,
- Diabetes,
- Heart attack,
- Stroke,
- Liver disease,
- Cystic fibrosis,
- Alzheimer’s,
- and Parkinson’s disease (2).
In this article, we’ll look at the best way to take glutathione and key considerations for its safe and effective use.
Glutathione - Dosage
Although the daily intake of glutathione is not officially established, it is most common in supplements at doses between 50 and 500 mg. Clinical research shows significant health-promoting effects at a daily intake of 250 to 1000 mg.
The studies demonstrated that long-term supplementation is responsible for an increase in blood glutathione levels (3). Read more about glutathione supplementation in our article: "How much glutathione should I take?".
Glutathione supplementation is well-tolerated, but long-term high doses should be monitored to prevent potential side effects, such as lower zinc levels. Prolonged high doses may reduce zinc levels, as glutathione influences metal ion balance in the body.
Glutathione: How to use it correctly?
For maximum absorption when using glutathione, it is important to take your oral dose on an empty stomach. Which means at least 30 minutes before a meal or 2 hours after.
Therefore, glutathione is best taken in the morning or between meals, as food (especially protein) can interfere with its absorption.
Water is the most recommended option for consumption, as it does not contain compounds that might hinder its effectiveness. Follow medical guidance for different recommendations.
Common mistakes to avoid when taking glutathione supplements
- Caffeine: it is important to avoid coffee for a few hours before and after taking glutathione, as caffeine can change how your body metabolizes it. Caffeine and tannins can interfere with glutathione absorption, including reducing the effectiveness. Besides that, caffeine can affect liver metabolism and potentially diminish the availability of glutathione (4).
- Alcohol: avoiding alcohol when taking glutathione is recommended because both are processed by the liver. Therefore, alcohol consumption can compromise glutathione metabolism. Besides that, alcohol is known for its production of free radicals that can cause cell and tissue damage and may affect glutathione effectiveness.
- Dairy foods: while there is no strong evidence requiring the avoidance of dairy when taking glutathione, some sources suggest it might interfere with absorption due to its proteins, minerals like calcium, or effects on stomach pH. Additionally, lactose intolerance or casein sensitivity in some individuals could cause digestive discomfort, potentially affecting supplement processing.
Special populations
While glutathione is safe for most individuals, certain populations require additional caution due to unique physiological or medical conditions. Pregnant and breastfeeding individuals should avoid glutathione supplements unless specifically recommended by a healthcare provider due to insufficient safety data.
Additionally, individuals with asthma, cancer, autoimmune diseases, and renal diseases should only use glutathione under medical supervision.
Practical tips to enhance glutathione levels
Glutathione levels in humans can be enhanced by consuming fruits and vegetables that either contain glutathione or provide amino acids that support its synthesis. To preserve glutathione, it is recommended to eat green foods such as asparagus, avocado, cucumber, green beans, and spinach, either raw or lightly steamed (5).
Participating in regular physical exercise boosts antioxidant protection and supports the natural production of glutathione. Incorporating stress-reducing practices such as meditation and exercises is important to enhance glutathione levels and support its effectiveness.
Supplements that can enhance glutathione activity
- Quercetin: a flavonoid found in foods like onions, apples, and berries, helps neutralize free radicals and reduces inflammation. It also boosts the activity of glutathione by regenerating its oxidized form, ensuring its availability for cellular detoxification.
- N-acetylcysteine (NAC): It plays a crucial role in supporting various physiological functions, primarily through its ability to boost glutathione levels, a powerful antioxidant vital for cellular detoxification and oxidative stress reduction.
- Vitamin C: Vitamin C and glutathione work together to enhance antioxidant defense, with vitamin C recycling oxidized glutathione back into its active form, ensuring its availability for neutralizing free radicals and supporting detoxification.
- Selenium: Selenium supports glutathione peroxidase, an enzyme that uses glutathione to combat oxidative stress and protect cells. Together, selenium and glutathione strengthen antioxidant defenses, boost immunity, and promote overall health and cellular function.
Find quercetin in our shop:
Conclusion
Glutathione is a vital antioxidant that regulates cellular redox balance and combats oxidative stress. Deficiency can lead to conditions like inflammation, cancer, diabetes, and neurodegenerative diseases. While daily intake varies, clinical studies suggest that 250-1000 mg boosts blood glutathione levels.
For optimal absorption, take glutathione on an empty stomach with water, avoiding caffeine, alcohol, and dairy food. Pregnant individuals and those with asthma, cancer, or renal disease should consult a doctor before use.
To enhance levels naturally, consume foods like spinach, avocado, and asparagus, engage in exercise, and reduce stress. Supplements such as N-acetylcysteine, quercetin, selenium, and vitamin C also support glutathione activity.
You can read more about supplements that enhance glutathione activity in one of our previous articles:
Literature sources:
- Ferreira MJ, Rodrigues TA, Pedrosa AG, Silva AR, Vilarinho BG, Francisco T, Azevedo JE. Glutathione and peroxisome redox homeostasis. Redox Biol. 2023 Nov;67:102917. doi: 10.1016/j.redox.2023.102917.
- Vašková J, Kočan L, Vaško L, Perjési P. Glutathione-Related Enzymes and Proteins: A Review. Molecules. 2023 Feb 2;28(3):1447. doi: 10.3390/molecules28031447.
Lee E, Park HY, Kim SW, Kim J, Lim K. Vitamin C and glutathione supplementation: a review of their additive effects on exercise performance. Phys Act Nutr. 2023 Sep;27(3):36-43. doi: 10.20463/pan.2023.0027. - D'Alessandro A, Fu X, Reisz JA, Kanias T, Page GP, Stone M, Kleinman S, Zimring JC, Busch M; Recipient Epidemiology and Donor Evaluation Study-III (REDS III). Stored RBC metabolism as a function of caffeine levels. Transfusion. 2020 Jun;60(6):1197-1211. doi: 10.1111/trf.15813.
- Al-Temimi AA, Al-Mossawi AE, Al-Hilifi SA, Korma SA, Esatbeyoglu T, Rocha JM, Agarwal V. Glutathione for Food and Health Applications with Emphasis on Extraction, Identification, and Quantification Methods: A Review. Metabolites. 2023 Mar 24;13(4):465. doi: 10.3390/metabo13040465.
