What Is Glutathione?

What Research Has to Say About Glutathione Supplements

Glutathione is an antioxidant found naturally in your body. Also known as GSH, it is produced by the liver and nerve cells in the central nervous system and is made from three amino acids: glycine, L-cysteine, and L-glutamate. Glutathione can help metabolize toxins, break down free radicals, support immune function, and more.

This article discusses the antioxidant glutathione along with its uses and purported benefits. It also provides examples of how to get more glutathione in your diet.

Dietary supplements are not regulated the way drugs are in the United States. This means the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement tested by a trusted third party, such as USP, ConsumerLabs, or NSF. 
However, even if supplements are third-party tested, that doesn’t mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.

Supplement Facts

  • Active ingredient(s): Glutathione
  • Alternate name(s): GSH
  • Suggested dose: Insufficient data to support a recommended dose
  • Safety considerations: To be avoided if pregnant or breastfeeding

Verywell / Alexandra Gordon

Purported Uses of Glutathione

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.

Glutathione depletion is thought to be associated with certain health conditions, such as neurodegenerative disorders (e.g., Parkinson's disease), cystic fibrosis, and age-related diseases, as well as the aging process. Still, this does not mean that glutathione supplementation can necessarily be helpful for these conditions.

Glutathione has been studied for a wide range of uses, including but not limited to:

  • Cystic fibrosis
  • Chemotherapy-related toxicity
  • Parkinson's disease

However, there is limited scientific evidence to support the use of glutathione to prevent or manage any health condition.

Cystic Fibrosis

Studies have suggested that inhaled or oral glutathione may help improve lung function and nutritional status in people with cystic fibrosis.

Chemotherapy Side Effects

A systematic review evaluated studies looking at antioxidants' effects on chemotherapy-related toxicities. Eleven of the studies analyzed included glutathione supplementation.

Intravenous (IV) glutathione may be used in conjunction with chemotherapy to lessen the toxic effects of chemotherapy. In some cases, it may make it more likely that the chemotherapy regimen can be completed. More research is still needed.

Parkinson's Disease

In one study, IV glutathione (600 milligrams twice daily for 30 days) significantly improved symptoms associated with previously untreated Parkinson's disease. However, the study was small, only consisting of nine patients.


Click Play to Learn About Glutathione’s Side Effects on Skin

This video has been medically reviewed by Meredith Bull, ND.

Glutathione Deficiency

Glutathione is not considered an essential nutrient since it is produced from other amino acids in the body.

Low levels of glutathione in the body can occur with poor nutrition, environmental toxins, stress, and increased age. Low glutathione levels have been associated with an increased risk of cancer, diabetes, hepatitis, and Parkinson's disease. However, this doesn't necessarily mean supplementing with glutathione decreases your risk.

Since glutathione levels in the body aren't usually measured, there is not much information on what happens to people with low glutathione levels.

What Are the Side Effects of Glutathione?

Due to a lack of research, little is known about the side effects of using glutathione supplements. No side effects have been reported with a high glutathione intake from diet alone.

However, there's some concern that using glutathione supplements may cause cramping and bloating or allergic reactions, with symptoms like a rash. In addition, inhaled glutathione has caused breathing problems in some people with mild asthma. If any of these side effects occur, stop taking the supplement and discuss it with your healthcare provider.

Long-term use of glutathione supplements may lower zinc levels.


Glutathione supplements are generally recognized as safe.

There is not enough data to show that it is safe for pregnant or nursing individuals. Therefore, glutathione supplementation is not recommended for use if you are pregnant or breastfeeding. Always talk to a healthcare provider before starting any supplement.

Dosage: How Much Glutathione Should I Take?

There is not enough scientific evidence to determine the proper dose of glutathione.

Various doses have been studied in research investigating specific medical conditions. The proper dose for you may depend on several factors, including your age, sex, and medical history.

In studies, glutathione doses given ranged from 250 to 1,000 milligrams daily. One study found that a minimum of 500 milligrams daily for at least two weeks was needed to increase glutathione levels.

In some cases, healthcare professionals administer glutathione through the use of an IV.

For some conditions, glutathione can also be inhaled and given through a nebulizer.

What Happens If I Take Too Much Glutathione?

There is not enough information yet to determine whether glutathione toxicity can occur.


There is insufficient data to know how glutathione interacts with certain medications and other supplements.

How to Store Glutathione

Be sure to follow manufacturer directions for how to store supplements. It may vary depending on the form of the supplement.

Always keep medication and supplements out of reach of children.

Similar Supplements

Glutathione may come as a single supplement or combined with other ingredients.

Additionally, supplementing with other nutrients may help increase glutathione production in the body. These can include:

Frequently Asked Questions

  • Does glutathione help to lighten your skin?

    Glutathione may help reduce melanin, but there is not enough good research data to say that glutathione supplementation helps to lighten your skin.

    A study done in Indonesia found that glutathione did not result in any significant skin-lightening or beneficial skin changes.

    Another systematic review reported inconclusive findings regarding glutathione's skin-whitening effect.

    IV glutathione is marketed for skin lightening because oral supplements have low bioavailability, but there is also little to no research to support this therapy. Additionally, research done in the Philippines found several severe adverse effects of IV glutathione, including:

    • Stevens-Johnson Syndrome (rare but serious disorder of the skin and mucous membranes)
    • Severe abdominal pain
    • Thyroid dysfunction
    • Kidney dysfunction
    • Air embolism (an air bubble in the blood vessels)
    • Sepsis (life-threatening response by the body to an infection)

    However, some of these complications may have been related to improper IV techniques or counterfeit glutathione, according to the researchers.

  • Can glutathione be used to treat Parkinson's disease?

    No dietary supplement should be intended to treat a disease. There is limited research on glutathione for Parkinson's disease.

    In one study, IV glutathione did improve symptoms in early Parkinson's disease. However, the study was small and only consisted of nine patients.

    Another randomized clinical trial also found improvements in people with Parkinson's who took intranasal glutathione. However, it did no better than the placebo.

Sources of Glutathione & What to Look For

Glutathione is readily found in certain foods, such as fruits and vegetables. A study published in Nutrition and Cancer found that dairy products, cereals, and bread are generally low in glutathione, whereas fruits and vegetables have moderate to high amounts of glutathione. Freshly prepared meats are relatively high in glutathione.

It can also be obtained in dietary supplements, such as in capsules, liquids, or topical forms. It can also be given intravenously.

Food Sources of Glutathione

Good food sources of glutathione include:

  • Broccoli
  • Cauliflower
  • cabbage
  • Brussel sprouts
  • Broccoli
  • Onion and garlic
  • Asparagus
  • Potatoes
  • Peppers
  • Carrots
  • Avocado
  • Squash
  • Spinach
  • Melon

Glutathione Supplements

Glutathione dietary supplements and personal care products are available online and in many natural-food stores, drugstores, and vitamin shops. Glutathione supplements are available as a capsule, liquid, inhalant, topical, or can be given intravenously.

Be sure to look for supplements that are third-party tested. This means that the supplement has been vetted and has the amount of glutathione that the label claims, and it is free of contaminants. Supplements with labels from the USP, NSF, or ConsumerLabs have been tested.


Glutathione has several roles in the body, including its antioxidant effects. Low levels of glutathione in the body are associated with many chronic conditions and diseases. However, there is not enough research to know if supplementing glutathione reduces the risk of those conditions or provides any health benefit.

Glutathione is made in the body from other amino acids. It is also found in the food we eat. Be sure to talk with your healthcare provider about the benefits and risks of supplementing before starting any dietary supplements.

19 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Jennifer Lefton, MS, RD/N, CNSC, FAND
Jennifer Lefton, MS, RD/N-AP, CNSC, FAND is a Registered Dietitian/Nutritionist and writer with over 20 years of experience in clinical nutrition. Her experience ranges from counseling cardiac rehabilitation clients to managing the nutrition needs of complex surgical patients.

Originally written by Cathy Wong
Cathy Wong

Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health.

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