If you encounter glutathione (GSH) in the aisle of your favorite nutritional supplements store, you may see it marketed as a detoxifier, immune system booster, or “master antioxidant.” You may have also heard through the grapevine that some people use it before they party to reduce the impact of drinking alcohol. But you may not have heard that the U.S. Food and Drug Administration (FDA) has issued warnings about a specific use of glutathione supplementation practiced by people around the world in the name of beauty.
Read on to learn about the health benefits, limitations, and possibly negative side effects of taking glutathione supplements.
What Is Glutathione, and What Does It Do?
Glutathione (gloo-tah-thy-ohn) is an amino acid compound that is naturally present in cells throughout the body. (1) Cysteine, glutamic acid, and glycine are the three amino acids that comprise it. Glutathione acts as an antioxidant, preventing and delaying cell damage, as well as detoxifying chemicals within the liver. (1) It is also important to immune system health and the regulation of cell growth and death. (2) Furthermore, the amino acid compound has the ability to bind itself to drugs, making them easier for the body to excrete. (3) But levels of glutathione in the body appear to decrease with age, experts say.
What Are the Possible Health Benefits of Glutathione?
Next, let’s take a look at all the possible health benefits of glutathione.
Glutathione Is an Antioxidant That May Help Fight Oxidative Damage
Without a doubt, the biggest health benefits of glutathione are the result of its antioxidant properties. Oxidative stress, which occurs when the balance of free radicals and antioxidants skews in favor of free radicals, can result in cell damage. (4) Research shows this process is linked to cancer, autoimmune disorders, cataracts, rheumatoid arthritis, cardiovascular and neurodegenerative diseases, and accelerated aging itself. (5)
The presence of glutathione helps guard against oxidative stress, and depletion of the amino acid compound is also associated with those disorders. (6) Research into the benefits of glutathione supplementation often looks at whether replenishing it in the body will help relieve oxidative stress, and therefore improve health and guard against the effects of aging.
For instance, glutathione levels are depleted in people with Parkinson’s disease, a neurodegenerative disorder that affects movement. That knowledge has spurred research into whether supplements can help with the symptoms of the illness. (7) Results of one study, in which people with Parkinson’s disease were given intranasal glutathione three times daily over three months, saw participants’ symptoms improve during the trial, but no more than the improvements demonstrated in the placebo group.
Results of another study of people with Parkinson’s disease who were given glutathione intravenously showed “the possibility of a mild symptomatic effect.” (8)
Yet the belief that glutathione has a beneficial effect on brain functioning motivates a number of clients that Miller sees to take oral supplements (which she recommends and takes herself). “Probably 50 percent of our clients take it because they feel some sort of improved brain function from it, or improved cognition,” she says. Nonetheless, most registered dietitians recommend getting nutrients from whole foods rather than supplements whenever possible.
Glutathione Appears to Have a Detoxifying Effect
As mentioned, glutathione is also a detoxifier. “It is responsible for binding to and conjugating a lot of toxins in our liver,” says Danielle Citrolo, PharmD, vice president, scientific and regulatory affairs for Kyowa Hakko USA, which sells an oral glutathione supplement under the brand name Setria.
Research indicates that conjugation is a process in the liver in which enzymes, such as glutathione, help make foreign substances, such as drugs, more soluble and easily excreted by the kidneys. (9) Dr. Citrolo cites the conjugation of acetaminophen (Tylenol), which can cause liver damage in high doses, as an example of glutathione protective benefits. (10)
Do People Use Glutathione to Help With the Effects of Drinking Alcohol?
Glutathione also has a role in metabolizing alcohol. (11) When ethanol (alcohol) is processed in the body, a carcinogenic byproduct, acetaldehyde, forms. Glutathione contains the amino acid L-cysteine, which breaks down acetaldehyde into water and carbon dioxide, which are then eliminated in urine. “When we drink excessively, our glutathione levels are lowered,” says Citrolo.
Miller says many of her clients who take glutathione supplements do it believing it can counteract the effects of taking Tylenol or drinking alcohol. “They may take it every time that they have a drink. Or if they go out and drink a little more heavily, they will take glutathione before bedtime to hopefully counteract that a little bit. Also for every time they need to take Tylenol.”
Despite the beliefs of those who take them, oral supplements may not necessarily confer all of the health benefits that you receive from the glutathione that is naturally produced by your body. “It has a very low oral bioavailabilty, which means that when you take a capsule of glutathione, and it reaches your gastrointestinal tract, a large majority of it gets degraded before it’s absorbed into the bloodstream,” says Seemal Desai, MD, an assistant professor of dermatology at the University of Texas Southwestern Medical Center.
Miller says that to get around that problem, she recommends a liposomal form of oral glutathione, which employs a drug nanodelivery system that encapsulates the amino acid compound in a membrane of lipids (organic compounds that are insoluble in water).
Still, research into the effectiveness of liposomal glutathione is early. For example, a one-month pilot study found that daily liposomal glutathione helped increase glutathione supply in 12 subjects, thereby boosting their immune system and lowering oxidative stress. (12)
Another type of glutathione supplementation — intravenous — is used around the world for a controversial purpose: to lighten the skin.
How Effective and Safe Is Glutathione as a Skin Lightener?
As described in an article in the The New York Times, injectable glutathione is attracting growing interest, both in countries around the world and increasingly in the United States, among people (particularly women of color) who wish to lighten their skin tone or fade dark spots. (13)
Some do it to conform to cultural pressures that favor lighter complexions over darker ones, especially in women. It’s true that naturally occurring glutathione can convert melanin to a lighter color and deactivate the enzyme tyrosinase, which helps produce the pigment. Still, the FDA warns that intravenous treatments “are potentially unsafe and ineffective and might contain unknown harmful ingredients or contaminants. The FDA has not approved any injectable drugs for skin whitening or lightening.” (14)
The risk of contaminants or infection from injections is a serious concern, says Oma Agbai, MD, director of multicultural dermatology and hair disorders at UC Davis Health in Sacramento, California. “It’s so unregulated that when someone goes to a med spa or some kind of clinic to get this kind of treatment, you don’t really know what you’re injecting.” If staff are poorly trained in injection techniques, “There is a risk for infection, such as fatal sepsis [blood poisoning],” she adds.
In fact, the Food and Drug Administration of the Philippines warned that repeated injections of glutathione could lead to kidney failure, blood poisoning, and toxic epidermal necrolysis, a life-threatening infection that causes skin to peel off. (15)
Furthermore, there have not been any long-term, large clinical trials to confirm the skin lightening effects of glutathione supplements in any form, though a review article reported that a handful of small, randomized, controlled trials have shown oral and topical supplements to be safe and temporarily effective in lightening skin. (16)
Further research is needed before dermatologists like Dr. Desai will recommend them for evening out hyperpigmentation [areas of skin that become darker than the surrounding area]. “We haven’t found a form that really works for skin issues,” he says.
In fact, glutathione is not approved at all by the FDA for dermatological use, Desai continues. If someone comes to his office requesting it, he says he would steer them toward other options — “other skin-lightening agents, in-office procedures, some special sunscreens, things like that.”
Meanwhile, those who are more concerned with inner health than outer appearance can rest assured that even if they never go near a glutathione supplement, the amino acid compound is nevertheless hard at work performing vital functions throughout their bodies, 24 hours a day, seven days a week.
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