Health Benefiits, Side Effects and Dosage Info

Antioxidants serve an invaluable part in looking, feeling and being healthy by preventing unstable molecules, know as free radicals, from inflicting damage to the bodies cells. In some cases diet alone is insufficient to produce and maintain enough antioxidant levels in the body, especially as we age or are under the weather, and supplements may offer a reliable compliment.

One of the most powerful of these antioxidants is glutathione, also referred to as “the master antioxidant.” Your body produces it naturally, and it can also be obtained through diet and supplements. It is one of the most abundant antioxidants in your body, and it is located in all of your cells. It is constantly being produced, used and then replenished. Glutathione can become easily depleted as it works to destroy free radicals and help to prevent the damage that they can cause to your cells which can lead to illnesses and premature aging.

It may have the potential to perform many additional functions in the body although currently, research is limited. Read on to learn more about this mighty antioxidant and if supplementation is right for you.

What is glutathione?

Glutathione is made up of three amino acids, a.k.a. the building blocks of protein. These include cysteine, glutamine and glycine. Your body naturally contains more glycine and glutamine, but cysteine can be in short supply. The good news is that cysteine is found in many foods and you can help boost your supply through diet. Additionally, there are many other vitamins and minerals that can help to increase overall levels of glutathione in your body.

As you age, the glutathione levels in your body begin to decrease. Additionally, chronic colds, illnesses, toxin exposure (i.e. air pollution, cigarette smoke) and inflammatory conditions such as pulmonary and cardiovascular diseases, alcoholism, etc. can cause glutathione to be used at an excessive rate, leading to depletion. Luckily, glutathione is available in supplement forms, and it is found in foods such as fruit and vegetables, so making changes to improve your diet and lifestyle may work to boost your overall levels.

Glutathione health benefits:

While there is no question it is a powerful antioxidant, in many of the studies we looked at, more research is needed to identify appropriate dosages and forms of glutathione. However, here are a few areas where it can be beneficial for the body.

• May slow the rate of oxidative stress: High levels of oxidative stress can lead to inflammatory conditions (diabetes, cardiovascular disease and autoimmune disease) and illnesses such as cancer. Studies have shown that glutathione can help prevent cell damage from oxidative stress, reducing inflammation and slowing down the process of oxidative stress.
  
• May help with COVID-19 symptoms: One study found that low levels of glutathione (GSH) could be associated with causing the excessive inflammatory response linked to severe cases of COVID-19. The study indicated that increasing levels of GSH in the body could potentially reduce the number of patients that were symptomatic, although more research is needed. And it’s important to note glutathione cannot prevent or treat COVID-19.
• May help with type II diabetes: A study showed that patients with type 2 diabetes had lower levels of glutathione in their blood when compared with a non-diabetic control group. The study indicates this may not be because the patients aren’t producing enough glutathione, it may be because glutathione is being used at a higher rate in patients with type II diabetes. More studies are needed to determine if improving blood sugar levels will in fact increase levels of glutathione in the blood or if oral supplementation could help or maybe, the combination of both.
• May help with cystic fibrosis: Glutathione has been associated with being helpful in the management of cystic fibrosis, a genetic lung disease. Studies have shown that people with this disease have lower levels of glutathione in their airways. Supplementation has also be thought to reduce inflammation and improve nutritional status in these patients, although a recent study found no significant difference in participants that supplemented orally with glutathione. More studies looking at different ways of administering glutathione, such as intravenously, are needed to determine if it could be helpful.
• May help with Parkinson’s disease: Clinical studies show that glutathione has the ability to improve motor function in patients with Parkinson’s disease. It has not been shown to improve mood, behavior or the ability to perform daily activities. While supplementation may provide symptomatic benefits, an appropriate dosage has yet to be determined.
• May help with rheumatoid arthritis: Studies show that supplementing with glutathione may help to control immune cells by preventing them from attacking normal body cells. Glutathione may be effective in preventing destruction of joint tissues and muscles in rheumatoid arthritis patients by neutralizing the free radicals that would otherwise destroy these cells.

What food sources contain glutathione?

Many fruits and vegetables contain glutathione or substances that can help to produce more glutathione in your body including sulfur rich foods because they contain a sulfur amino acid, cysteine (one of the amino acids that makes glutathione). These foods include cruciferous vegetables such as: broccoli, cabbage, cauliflower, kale, arugula, etc. The best method of preparing them is raw or lightly steamed because heat can damage the amount of sulfur compounds available. Beef, fish, eggs and poultry are also sulfur-rich proteins.

Other foods that are high in glutathione include:

• Avocado
• Watermelon
• Asparagus
• Grapefruit
• Strawberries
• Okra
• Tomato
• Peach
• Zucchini
• Spinach

Additionally because glutathione is formed from amino acids, consuming dietary forms of protein may help your body to produce more glutathione. According to research, a good potential source of protein that could increase levels is whey protein because it is also higher in the amino acid cysteine.

Does glutathione have any side effects?

Side effects of glutathione are not well known. A review of the research literature has failed to show any serious side effects, although there have been reports of gastric cramping nausea, abdominal bloating and allergic reactions. There are many ways of administering glutathione, such as intra-nasally and intravenously that could require medical supervision. We recommend discussing options first with your healthcare provider before adding new supplements to your diet. Additionally, you can always work to boost levels through a healthy and well-balanced diet.

Is it safe to take glutathione supplements?

The U.S. Food and Drug Administration (FDA) does not approve supplements for safety and effectiveness, so we recommend choosing brands that have been tested by a credible third-party for purity, potency and safety. Select brands that are verified by USP or NSF and carry their individual seals, or ones that are granted by an independent, third party organization that asserts quality control via purity tests and ingredient fact-checking.

Glutathione supplements are generally considered to be safe as an oral supplement. No serious side effects were observed in many clinical trials. Glutathione supplements should be avoided during pregnancy and breastfeeding, and they should always be discussed with your healthcare provider before adding them to your regimen.

Here are some of our top glutathione supplement picks:

NOW Glutathione with Milk Thistle Extract & Alpha Lipoic Acid

Quicksilver Scientific Lemon Mint Liposomal Glutathione

Thorne Research Glutathione-SR Capsules

Toniiq Glutathione Capsules

There are also other vitamins, minerals antioxidants and substances that work to increase overall levels of glutathione in the body including:

• N-Acetyl Cysteine (NAC): This form of cysteine may be easier for your body to absorb over other types and it may help to increase overall levels of glutathione. It is also naturally found in garlic and onions.
• Alpha-Lipoic Acid: Also a very powerful antioxidant that works to recycle glutathione.
• Selenium: This mineral is a cofactor to glutathione which means it is needed in the body to produce more glutathione.
• Omega-3 fatty acids: May help to decrease inflammation and improve glutathione levels.
• Vitamin C & E : These vitamins work together to produce glutathione.
• B Vitamins: These vitamins work as a necessary coenzyme in your body to produce glutathione. Deficiency in vitamin B12 is associated with lowered levels of glutathione.
• Milk Thistle (a.k.a. silymarin): May help to boost overall levels of glutathione.

What happens if I take glutathione every day?

Data on providing oral glutathione are mixed and inconclusive. Research indicates that intravenous, liposomal and sublingual (applied under the tongue) methods of supplementation may be better choices over oral supplementation because they are not broken down during digestion which can prevent adequate absorption. Some studies have shown that when glutathione was given in doses of up to 5g per day, both orally and intravenously, no toxicity was observed. Take note, these doses were administered in controlled settings, we recommend speaking with your healthcare provider before adding any new supplements to your diet.

The bottom line:

The goal is to maximize the amount of antioxidants in your diet. First efforts should be through food, and then supplementation, which offers a reliable path to fill in the gaps. Glutathione is depleted during stress, illness and aging. Focusing on improving your diet, lifestyle and overall wellness can help to maintain and/or boost your overall levels of this super-powered antioxidant.

For more supplements to boost your overall health, checkout our guide to multi-vitamins, probiotics and magnesium. If you need some added wellness motivation, our 8-week healthy habit guide that can set you on the right path.

Contributing Writer

Amy (she/her) is a registered dietitian with the Nutrition Lab at the Good Housekeeping Institute, covering nutrition- and health-related content and product testing. She holds a bachelor’s degree in journalism from Miami University of Ohio and a master’s degree in clinical nutrition from NYU. Prior to Good Housekeeping, she worked at one of the largest teaching hospitals in New York City as a cardiac transplant dietitian. She has authored numerous chapters in clinical nutrition textbooks and has also worked in PR and marketing for food company start-ups.