Antioxidants, like the increasingly popular glutathione, are crucial for protecting your healthy cells from damage. How? They fight back against free radicals, which are unstable molecules created when your body processes oxygen. You end up with too many free radicals when you’re exposed to things like pollution, cigarette smoke and UV light.
Antioxidants have been shown to help prevent certain chronic diseases often linked to that free radical damage.
[SEE: Top Habits and Trends for Healthy Aging: 2025 U.S. News & World Report Healthy Aging Survey]
What Is Glutathione?
Glutathione is one of the antioxidants that your body, especially the liver, produces from a combination of three amino acids:
— Cysteine
— Glutamic acid
— Glycine
Other antioxidants, such as vitamin C and vitamin E, come from the food you eat. Both the antioxidants produced by your body and the antioxidants you get from food protect healthy cells from free radicals.
Glutathione Benefits
The antioxidant glutathione provides a broad array of health benefits, says Dr. Jacob Teitelbaum, a board-certified internal medicine physician and author of the book “From Fatigued to Fantastic: A Manual for Moving Beyond Chronic Fatigue & Fibromyalgia.”
Health benefits provided by glutathione produced by the body include:
— Breaking down certain free radicals
— Reducing excess inflammation
— Delaying cell damage
— Helping the liver detoxify different chemicals
— Producing and repairing DNA
— Supporting the immune system
— Transporting mercury out of the brain
In addition, glutathione in the body helps protect against a variety of health problems, Teitelbaum says. Glutathione, which is also known as GSH, “is critical in almost every system of the body in protecting us from the inflammatory stresses of modern life.”
These health problems can include:
— Brain inflammation
— Cancer
— Chronic fatigue syndrome
— COVID-19-related inflammation/long COVID
Glutathione also naturally decreases with age.
“When glutathione is depleted, there’s an association with many chronic disorders,” says Amy Kimberlain, a registered dietitian nutritionist and certified diabetes care and education specialist based in Miami. She is also a spokesperson for the Academy of Nutrition and Dietetics. “This is where supplementation has come into discussion. If the levels of glutathione are replaced or supplemented, does this then make an impact and ultimately improve one’s health?”
[Read: How Aging Affects Your Immunity]
Do Glutathione Supplements Work?
Taking glutathione supplements isn’t an evidence-backed way to improve your health. While there’s no question that glutathione produced by the body has a number of health benefits, the benefits of glutathione supplements are not established.
“There’s not enough research to conclude the supplement is effective,” says Dr. Rahul Dixit, an internal medicine physician, gastroenterologist and hepatologist with Digestive Health Associates in Santa Monica, California. “Consumers need to know that more robust clinical trials are needed for glutathione supplements.”
There’s scant research to suggest that taking glutathione supplements provides health benefits, agrees Dr. Sameer Murali, associate professor of surgery with McGovern Medical School at UTHealth Houston and obesity medicine specialist at Memorial Hermann, the largest not-for-profit health system in southeast Texas.
“A more important question might be (to) consider whether the prevalence and/or severity of pro-inflammatory conditions have a deeper common origin, and in fact, they do,” Murali says. “Over and over, researchers have found that lifestyle behaviors like inadequate sleep, physical activity, social connectedness and vegetable intake are linked to the leading causes of death in the United States, such as cancer and heart disease.”
[READ: 17 Best Anti-Inflammatory Foods]
Additional glutathione supplement research
A couple of studies, however, suggest GSH supplements could have potential.
Research published in the journal Antioxidants in 2020 suggests that “the use of liposomal GSH (a glutathione supplement) could be beneficial in COVID-19 patients.”
In a very small study published in 2018 in the European Journal of Clinical Nutrition, researchers wrote that increases of GSH levels in 12 adults who were provided glutathione supplements over a period of one, two and four weeks experienced reductions in oxidative stress and enhancements in immune function.
While many experts say more research is needed to determine the efficacy of glutathione supplements, Teitelbaum says such supplements, particularly slow-release capsules, can be effective. Many glutathione capsules that aren’t slow-release are digested before they can be absorbed, losing much of their potency. There’s also some evidence that glutathione will be broken down by enzymes in the stomach and thus will not be absorbed as glutathione.
It’s important to keep in mind that supplements are not regulated like drugs and other medications. Instead, they’re regulated by the Food and Drug Administration as food.
In fact, it’s important to be aware of misleading claims by some firms that market such products. For instance, in 2019 the FDA sent 12 warning letters and five advisory letters to companies for misleading claims about roughly 60 products, many of them supplement companies. One of these letters was sent to a company claiming that its glutathione supplements were the key to preventing heart disease and dementia and necessary for treating Alzheimer’s disease and other conditions.
How to Take Glutathione and Glutathione Supplements
Glutathione can be used in a few different ways:
— Taking the supplement orally (in capsule or liquid form) is the most common way.
— Injecting glutathione, which is less common, may be used in those with Parkinson’s disease or to counteract side effects from certain chemotherapy drugs for cancer. It’s also been used by some as a skin lightener at beauty salons and spas. However, using it in this form could have negative effects on the liver, kidneys and nervous system.
— It is occasionally used in an inhaled form for respiratory conditions. However, it’s possible for the inhaled form to worsen asthma.
— Topically, it is used to reduce dark spots.
Let your health provider know about glutathione or any supplements you’re using to make sure they don’t interact with your other medications.
Teitelbaum recommends using a reduced form of glutathione, which is an active form of it. You also may consider a form called liposomal glutathione, which may be absorbed by the body more effectively. It’s also pricier than the reduced form of glutathione.
[SEE: NAD+ Therapy: The Secret to Anti-Aging? Benefits, Side Effects and Safety]
Glutathione Side Effects
Although glutathione is considered safe, supplements may cause side effects in some people, including abdominal pain or bloating. The topical form could cause a rash or itching if you’re allergic to it.
What to avoid when taking glutathione
Some things to avoid when taking a supplemental form of glutathione include:
— Alcohol, as it can lower your glutathione levels
— Acetaminophen (the generic name for Tylenol), as this also can lower your glutathione levels
— Smoking, which creates free radicals in the body
Getting Glutathione From Food
While many experts believe more research needs to be conducted to determine whether glutathione supplements are effective, you can consume a number of foods that are rich in glutathione.
These foods include:
— Asparagus
— Avocado
— Beef
— Broccoli
— Brussels sprouts
— Cauliflower
— Fish
— Garlic
— Kale
— Mustard greens
— Okra
— Poultry
— Watercress
[See: 10 Superfoods for Older Adults.]
Glutathione for Cancer Patients
Glutathione supplements may not be an option for cancer patients undergoing chemotherapy or radiation therapy, Teitelbaum says. These therapies work by creating oxidative stress to kill cancer cells, so some oncologists request their patients avoid antioxidant supplements, like glutathione, during their treatment. You should always speak with your health care provider before consuming supplements, especially when undergoing cancer treatment.
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What Is Glutathione? originally appeared on usnews.com
Update 01/21/26: This story was previously published at an earlier date and has been updated with new information.