Glutathione Side Effects
Glutathione (GSH) is an antioxidant produced in the body and found in foods and glutathione supplements. As an antioxidant, glutathione protects your cells against oxidative stress and against age-related declines.
Medical conditions, environmental factors, poor nutrition, and stress are associated with low glutathione levels, leading many people to take glutathione supplements to support their overall and cognitive health.
All medications and supplements have potential risks and benefits, which means they may not be suitable for everyone. Discuss the risks and benefits of glutathione with your healthcare provider to learn whether this important antioxidant can improve your health.
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Glutathione comprises three amino acids: cysteine, glycine, and glutamate. People commonly take supplements to fill a nutritional gap. Low glutathione levels are more common with age and in people exposed to environmental stressors.
Supplements are not intended to treat, cure, or prevent disease. For this and many other reasons, there is little research on the benefits, recommended dosage, or side effects of many supplements.
Glutathione has the following potential benefits:1,2,3
- Reducing inflammation
- Supporting the immune system
- Detoxifying the liver
- Improving skin health
- Lightening skin color
- Improving insulin resistance
- Recycling other antioxidants
- Supporting sperm production
Glutathione can also protect your cells from threats such as:4
- Chronic diseases
- Chronic stress
- Dietary deficiencies
- Environmental toxins, pollution, and radiation
- Excessive alcohol consumption
- Excessive or prolonged physical activity
- Sleep deprivation
- Unhealthy dietary choices
Side Effects of Oral Glutathione Supplements
Glutathione is generally recognized as a safe supplement.5 The Food and Drug Administration (FDA) does not regulate dietary supplements. The side effects associated with oral glutathione or other supplements are often not necessarily from the supplement but, instead, reactions to the binders or fillers used when making the product. Choose a supplement tested by USP, ConsumerLab, or NSF whenever possible.
Potential side effects associated with oral glutathione include:
- Abdominal cramping
- Skin rashes
- Excess gas
- Loose stools
Tips for Dealing With Oral Glutathione Supplement Side Effects
Since oral glutathione products may vary in ingredients, switching to another supplement may improve your symptoms. Other strategies to reduce gastrointestinal and other symptoms include:
- Stop taking the supplement until your symptoms resolve, and then restart it.
- Gradually increase your dose to the recommended dose over several weeks.
- Try taking the supplement with food or milk.
- Drink plenty of water before and after taking the supplement.
- Since increased glutathione may cause low zinc levels, ask your doctor whether a zinc supplement may help.
Side Effects of Glutathione Supplement Injections
Many people choose glutathione injections over oral supplements because they bypass the gastrointestinal system and deliver glutathione more directly to the body cells.
Glutathione side effects are rare. The most common side effects associated with glutathione injections include:
- Allergic reactions: Glutathione injections may cause allergic reactions in some people, including skin rashes, hives, and difficulty breathing.
- Blood clotting problems: Glutathione injections may interfere with blood clotting, which could increase the risk of bleeding and bruising. However, a long-term phase 4 study has not found an increased bleeding risk after using glutathione.
- Kidney and liver problems: Taking large doses of glutathione may cause kidney or liver dysfunction.
- Nausea and vomiting: Some people may experience nausea and vomiting after receiving a glutathione injection.
- Rash or irritation at the injection site: The injection site may become red, swollen, or painful after receiving a glutathione injection.
Tips for Dealing With Glutathione Supplement Injection Side Effects
If you have side effects from a glutathione injection, stop taking the injection and contact your healthcare provider for guidance.
Seek emergency care if you experience an allergic reaction involving facial, mouth, or tongue swelling.
For nausea and vomiting, drink plenty of fluids and consume a mild diet for a few days until your symptoms resolve. Don’t restart your injections until you have discussed your side effects with your healthcare provider.
There is some debate on the effectiveness of oral glutathione, as digestive enzymes in the stomach may break it down.5 However, researchers found that when participants in a clinical trial took either 250 or 1000mg of glutathione by mouth daily, they had significant increases in their body stores of glutathione. They also found that the glutathione increase was proportional to the dose.6
The recommended dosage for glutathione is unclear. Some studies have indicated that even doses up to 5 grams per day, either oral or intravenous, were not associated with toxicity.7
Natural Ways To Get More Glutathione
In addition to supplements, high-quality sleep, exercise, and a nutritious diet are essential to maintain or boost glutathione levels.
Implement a Nutritious Diet
Glutathione can also be obtained by consuming foods naturally rich in glutathione.
Foods that can boost your glutathione levels naturally include:
- Green beans
- Green tea
- Pomegranate juice
Choose a well-balanced, nutritious diet focusing on minimally processed whole foods to boost your glutathione levels naturally.
Be Mindful of Sleeping Habits
Sleep is an active process during which your body processes waste, repairs cells, and removes toxins. It is essential to have high levels of antioxidants to support these processes, but to get the best results, ensure you get 7 to 9 hours of restful sleep each night.
Sleep deprivation is associated with decreased glutathione levels and increased oxidative stress.8
- Avoid heavy meals before bedtime, especially if you are prone to gastroesophageal reflux and indigestion.
- Establish a bedtime routine that tells your brain and body that it is time for sleep.
- Help your brain set your circadian rhythm by spending a few minutes outside each morning, especially when the sun is out. If the season or weather is not cooperating, a light box can also help. Lightboxes are sometimes equipped with an alarm to make it easier to adjust your light exposure for optimum health.
- Limit caffeine intake after noon and alcohol intake within three hours of bedtime.
- Set a sleep schedule and stick to it. Whether you need 7 hours of sleep a night or 10, set a schedule seven days a week. While it is tempting to sleep in on weekends to “catch up” on your sleep, it doesn’t work very well.
- Sleep in a room that is cool, dark, and without distraction. Use blackout curtains and white noise to reduce stimuli that may keep your brain active.
- Try to get plenty of exercise throughout the day to relieve stress and improve your sleep quality.
- Turn off screens about an hour before bedtime. Electronic screens emit blue light that makes your brain think it is still daytime.
Regular exercise is another excellent way to boost your glutathione levels, and it has many other benefits as well! As your body adapts to increased exercise, it stores more glutathione to deal with the increased oxidative stress associated with exercise. While all exercise is important, aerobic exercise boosts glutathione levels the best.9 After exercising, ensure your body has plenty of time to rest and recover.
- Pizzorno J. Glutathione! Integr Med (Encinitas). 2014 Feb;13(1):8-12. PMID: 26770075; PMCID: PMC4684116.
- Mak TW, Grusdat M, Duncan GS, Dostert C, Nonnenmacher Y, Cox M, Binsfeld C, Hao Z, Brüstle A, Itsumi M, Jäger C, Chen Y, Pinkenburg O, Camara B, Ollert M, Bindslev-Jensen C, Vasiliou V, Gorrini C, Lang PA, Lohoff M, Harris IS, Hiller K, Brenner D. Glutathione Primes T Cell Metabolism for Inflammation. Immunity. 2017 Apr 18;46(4):675-689. doi: 10.1016/j.immuni.2017.03.019. Erratum in: Immunity. 2017 Jun 20;46(6):1089-1090. PMID: 28423341.
- Kumar, P, Liu, C, Hsu, JW, et al. Glycine and N-acetylcysteine (GlyNAC) supplementation in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, insulin resistance, endothelial dysfunction, genotoxicity, muscle strength, and cognition: Results of a pilot clinical trial. Clin Transl Med. 2021; 11:e372.
- Weschawalit S, Thongthip S, Phutrakool P, Asawanonda P. Glutathione and its antiaging and antimelanogenic effects. Clin Cosmet Investig Dermatol. 2017 Apr 27;10:147-153. doi: 10.2147/CCID.S128339. PMID: 28490897; PMCID: PMC5413479.
- Richie J.P., Jr., Nichenametla S., Neidig W., Calcagnotto A., Haley J.S., Schell T.D., Muscat J.E. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur. J. Nutr. 2015;54:251–263. doi: 10.1007/s00394-014-0706-z.
- Wang HL, Zhang J, Li YP, Dong L, Chen YZ. Potential use of glutathione as a treatment for Parkinson’s disease. Exp Ther Med. 2021 Feb;21(2):125. doi: 10.3892/etm.2020.9557. Epub 2020 Dec 4. PMID: 33376507; PMCID: PMC7751460.
- D’Almeida V, Lobo LL, Hipólide DC, de Oliveira AC, Nobrega JN, Tufik S. Sleep deprivation induces brain region-specific decreases in glutathione levels. Neuroreport. 1998 Aug 24;9(12):2853-6. doi: 10.1097/00001756-199808240-00031. PMID: 9760133.