all what you need to know about Glutathione

 Glutathione, often referred to as the "king of antioxidants," is one of the most comprehensive health molecules on the dietary supplement market. Glutathione is known to improve the health of the heart, skin, liver, brain and strengthen the immune system. But are its benefits scientifically proven? Have the tests of this molecule against Covid-19 been conclusive?

In this article, we study the real virtues of glutathione and answer your questions, scientific studies in support. You will discover how to naturally boost the synthesis of this remarkable antioxidant thanks to a diet rich in glutathione. We will also tell you where to find a quality product.

At the end of the article we answer frequently asked questions, including about graphene, weight gain and the pope's famous prescription for Parkinson's disease.

Glutathione the king of antioxidants


Glutathione (GSH) is the most powerful antioxidant in the human body [1]. It has a huge ability to fight oxidative stress and neutralize harmful free radicals. Chemically speaking, glutathione is a tripeptide composed of 3 amino acids: cysteine, glutamic acid and glycine.

When these three amino acids are combined into glutathione, they acquire the ability to detoxify dangerous free radicals, toxic drugs, and heavy metals. This mechanism protects the body against dysfunction and disease [2, 3].

In fact, to be healthy, the body must make glutathione. Scientists even indicate that glutathione level is an excellent predictor of lifespan [4, 5]. Moreover, glutathione deficiency increases sensitivity to oxidative stress, which can be the underlying cause of many diseases such as cancer, heart disease, Parkinson's disease and Alzheimer's disease [6].

Finally, it has been proven that glutathione levels are also associated with age. According to various studies, this rate begins to drop drastically from the age of 49, hence the appearance of various diseases or signs of aging [7].


Glutathione is therefore an antioxidant necessary for the health of the human body. But what are its real benefits? Many newspapers talk about glutathione to treat Covid-19, are these words justified?

In this section, we will first list the virtues of glutathione. Then, we will detail its advantages, scientific studies in support.


Fights oxidative stress

  • Eliminates free radicals.
  • Recharge of other antioxidants (vitamin C and E).
  • Prevents chronic diseases.

Fights infections

  • Reduces the incidence of bacterial infections.
  • Restores the capacity of immune cells.
  • Kills certain bacteria (tuberculosis).
  • Destroys microbes.

Fighting Covid-19

Avoids the severe effects of Covid-19.

Reduces inflammation

  • Blocks the production of most inflammatory cytokines.
  • Blocks NF-κ, the main controller of inflammation.

Has an anti-aging effect

  • Slows down the cellular aging process.
  • Strengthens bones.
  • Prevents age-related cognitive decline.

Promotes mental health

  • Fight against anxiety, depression and stress.
  • Protects against OCD and schizophrenia.
  • Beneficial against bipolar disorder.
  • Helps stabilize mood.

Autism and ADHD

  • Low levels of glutathione have been linked to autism and ADHD.

Protects the brain

  • Stimulates memory.
  • Reduces plaque buildup.
  • Improves the general symptoms of Alzheimer's.
  • One drug prevented Parkinson's disease by increasing glutathione levels.

Promotes gut health

  • Protects the intestinal mucosa against intestinal permeability.

Strengthens heart health

  • Prevents heart attacks.
  • Prevents strokes.

Contributes to the health of the lungs and airways

  • Fights asthma.
  • Reduces the risk of chronic obstructive pulmonary disease (COPD).
  • Reduces the risk of chronic obstructive pulmonary disease (COPD).

Protects the liver

  • Keeps the liver healthy.
  • Important role in the detoxification of the liver.
  • Prevents liver damage.

Fight against diabetes

  • Decreases the risks associated with diabetes (brain damage, heart damage, etc.)

Contributes to kidney health

  • Improves kidney function.
  • Reverses anemia.
  • Prevents kidney disease caused by aspartame.

Sleep apnea

  • Improves the quality of sleep.

Skin Health

  • Reduces acne by neutralizing oxidative stress.
  • Promotes skin regeneration.
  • Lightens women's skin.
  • Evens out the appearance of dark spots (aging).

Fights addictions

  • Helps overcome addictive behaviors (eating disorders, alcohol and drug abuse).
  • Protects the brain.
  • Helps to detoxify harmful substances from the body.
  • Improves liver function.

Eye health

  • Protects the eyes (glaucoma and cataracts).

Fights infertility

  • Plays an important role in germ cells.
  • Is involved in the process of fertilization and early development of the embryo.


Fights oxidative stress
Glutathione has excellent antioxidant potential. It eliminates free radicals throughout the body and recharges other antioxidants, thus preventing chronic diseases.

This is because glutathione reduces reactive oxygen species (ROS) and oxidative stress that damage cells and DNA. Oxidative stress is associated with cancer, inflammation, brain damage and other health problems [8, 9].

Glutathione is also important for the regeneration of other antioxidants, such as vitamin C and vitamin E. It thus supports our overall antioxidant defense [10].

Fights infections

Viral infections flood the body with oxidative stress due to inflammation by using more glutathione [11]. Thus, in many chronic diseases, low immunity and an increased rate of infections are linked to low levels of glutathione (GSH) [12].

In addition, once glutathione is depleted, immune cells lose their ability to fight infections. N-Acetylcysteine (NAC), which stimulates glutathione in the body, helps restore the ability of immune cells and kill certain bacteria including those responsible for tuberculosis, among others [13].

In another study, maintaining cysteine levels helped control glutathione. In turn, immune cells then regained the power to destroy microbes [14].

Finally, elderly AIDS patients produce less GSH, which weakens their already fragile immune systems and decreases insulin sensitivity. Increasing glutathione levels may help improve symptoms and reduce the incidence of bacterial infections [15-17].

What about the use of glutathione against Covid-19?

Scientific research has proven the link between glutathione deficiency and severe manifestations (including deaths) caused by Covid-19 [18-20].

According to a study conducted in May 2020 among several Covid-19 patients, it has been shown that:

"Glutathione deficiency appears to be a crucial factor responsible for SARS-CoV-2-induced oxidative damage to the lung and, therefore, leads to serious manifestations, such as acute respiratory distress syndrome, multi-organ failure and death in COVID-19 patients. [...] This finding suggests that the virus cannot actively replicate at higher levels of cellular glutathione and, as a result, milder clinical symptoms are observed with lower viral loads.

 Since the antiviral effect of glutathione is not specific, there is reason to believe that glutathione is also active against SARS-CoV-2. Therefore, restoring glutathione levels in COVID-19 patients would be a promising approach for the management of the novel coronavirus SARS-CoV-2. Notably, long-term oral administration of N-acetylcysteine has already been tested as an effective preventive measure against respiratory viral infections. N-acetylcysteine is widely available, safe and inexpensive and could be used "off-label*" [18].

*An off-label prescription means that it can be used for indications other than those for which the medicinal product has received its marketing authorisation. Off-label treatment makes it possible to treat diseases for which there is no specific treatment.

In summary: it has therefore been shown that Covid-19 would be more harmful and dangerous in people with low glutathione levels. Low levels of glutathione are linked to other chronic diseases (diabetes, inflammation, etc.) and age. This would explain why the coronavirus-related mortality rate is higher among these people.

Reduces inflammation

Glutathione and inflammation: a woman from behind who holds her shoulder with her hand. The area is in red to indicate pain, inflammation of the joint.Glutathione blocks the production of most inflammatory cytokines. In chronic health conditions, it is these molecules that keep the body in a constant state of low-grade inflammation [12]. Thus, a glutathione deficiency can cause inflammation. In addition, blocking inflammatory pathways restores glutathione levels. This suggests that glutathione and inflammation are closely related [21].

On the other hand, glutathione blocks NF-κ, the main controller of inflammation in the body. This protein complex increases the activity of various inflammatory genes and their products [22]. As such, a number of diseases of the respiratory and pulmonary tract are caused by excessive inflammation and can therefore be relieved by restoring healthy levels of glutathione [12].

Has an anti-aging action

Replenishing glutathione levels in the body can slow down the aging process, strengthen bones, and prevent age-related cognitive decline.

Indeed, several studies indicate that the body produces less of this antioxidant as it ages [6, 23]. Thus, without this antioxidant protection, free radicals can harm the body and accelerate the aging process, including cognitive decline.

In women, glutathione levels drop at the beginning of menopause, giving way to oxidative stress. In addition, increased oxidative stress caused by low levels of glutathione in the elderly has been associated with weaker bones and osteoporosis [24, 25].

Finally, glutathione-depleted cells are susceptible to damage. One study shows that low levels of glutathione trigger a cascade of events leading to cell damage and cell death, thereby accelerating the overall aging of the body [26].

Promotes mental health

Glutathione would fight anxiety, depression and stress. Indeed, research has found that people with depression have low levels of glutathione [27, 28]. In addition, some anxiolytic drugs work by increasing glutathione levels [29, 30].

Similarly, people with OCD and schizophrenia often have low levels of glutathione. Thus, the administration of N-Acetylcysteine (NAC), the purpose of which is to increase glutathione levels in the brain, has improved the symptoms of schizophrenia in clinical studies [31].

In addition, people with OCD usually have high blood levels of free radicals. Increasing glutathione can then improve antioxidant defense, stress resistance, and overall symptom severity [27, 30, 32].

Finally, since several medications used to treat bipolar disorder work by increasing glutathione levels, its natural increase may also help stabilize mood and symptoms[33].

Autism and ADHD

Children diagnosed with autism have glutathione levels about 20 to 40 percent lower. They also have various abnormalities in the manufacture and restoration of the active form of glutathione [34-37].

Similarly, people with ADHD have low glutathione levels and high levels of oxidative stress. As such, pycnogenol, a natural glutathione booster, normalized glutathione and antioxidant levels in children with ADHD [38, 39].

Protects the brain

Reactive oxygen species (ROS) are continuously generated while the brain burns fuel to produce energy. The brain needs to detoxify them to stay healthy, and glutathione plays a key role in making this possible.[40]

Alzheimer's disease is partly caused by oxidative stress. Antioxidants can prevent or slow down the disease. Several clinical studies have shown that oral vitamin E (another powerful antioxidant) slows the progression of Alzheimer's disease [41]. This was then tested with glutathione.

According to this study, increasing glutathione may boost memory, reduce plaque buildup, and improve general symptoms [41].

Parkinson's disease

People with Parkinson's disease have low levels of glutathione in the brain. Increasing GSH may be an early measure to prevent this disease [42].

In one study, a drug prevented Parkinson's disease by increasing glutathione levels [43].

Promotes gut health

According to research, people with chronic bowel disease (IBD) also have reduced activity of enzymes involved in glutathione synthesis, including cysteine [44].

The most important enzyme involved in the extinction of free radicals is called glutathione peroxidase. This enzyme uses glutathione and requires selenium to fight harmful substances. High levels of this enzyme indicate greater oxidative stress that needs to be neutralized [45, 46].

In addition, glutathione peroxidase also helps to renew and strengthen the intestinal mucosa. Thus, glutathione helps protect the intestinal mucosa, which may help prevent intestinal permeability[47].

Contributes to the health of the lungs and airways

Low levels of glutathione can increase inflammation of the airways and cause asthma. In one study, increasing glutathione with N-Acetylcysteine reduced inflammation and improved symptoms [48].

Chronic obstructive pulmonary disease (COPD) is a lung disease caused by long-term oxidative damage. Increased glutathione reduces free radical damage in the lungs, which reduces the likelihood of developing chronic obstructive pulmonary disease (COPD) [49, 50].

Protects the liver

Glutathione keeps the liver healthy by neutralizing oxidative stress that can lead to liver disease. It plays an important role in the detoxification of the liver and the protection of its tissues, rich in sulfur. It is partly thanks to sulfur that the liver removes all chemicals, drugs, drugs and synthetic products that may be contained in the diet [51-53].

Indeed, when faced with harmful substances, the liver produces more glutathione to prevent damage [54].

Strengthens heart health

Low activity of the enzyme glutathione peroxidase and low levels of glutathione are linked to high oxidative stress and an increased likelihood of heart attack [55-57].

Cardiovascular disease is largely caused by oxidative stress in heart tissue. Glutathione may reduce free radicals and, in turn, may prevent strokes or heart attacks [58, 59].


Type 2 diabetes and hyperglycemia lower glutathione in the body. This causes the accumulation of harmful free radicals and leads to many complications, such as heart problems, brain and nerve damage. Increasing glutathione may prevent or limit these problems.[60]

Kidney health

Oxidative stress in the kidneys can cause mild kidney problems or even complete kidney failure, depending on its severity. In a study of 20 people with chronic kidney disease on hemodialysis, glutathione improved kidney function and reversed anemia [61].

In another study, administration of N-Acetylcysteine (NAC) prevented kidney disease caused by aspartame, an artificial sweetener [62].

Sleep apnea

People with sleep apnea have high levels of oxidative stress and, as a result, depleted GSH levels. According to research, increasing glutathione levels to normal improved the quality of their sleep [63, 64].

Skin Health

Acne : Oxidative stress lowers glutathione in people with acne. Increasing glutathione levels can suppress acne by neutralizing oxidative stress and promoting skin regeneration [65-67].

Spots & Aging: Glutathione lightens the skin of healthy women. It reduces the activity of the skin cells that make dark pigments (melanin). As such, glutathione may help even out the appearance of dark skin spots that appear with aging [68, 69].

Fights addictions

Various drugs (such as cocaine and methamphetamines), as well as alcohol, increase the production of reactive oxygen species (ROS). These, in turn, can alter the brain and behavior or cause damage.

Some studies suggest that increasing glutathione may help overcome addictive behaviors such as eating disorders, alcohol and drug abuse [70-72].

Increasing antioxidant defense not only protects the brain, but it also helps detoxify harmful substances from the body. Chronic alcohol abuse reduces glutathione in the liver. Thus, increased GSH levels improved liver function during abstinence [70].

Eye health

Glaucoma and cataracts can gradually lead to blindness. Since oxidative stress underlies both, increased glutathione can protect the eyes.[73]

Fights infertility

Infertility is a global health problem and it is one of the most stressful conditions among married couples looking to conceive a child. Oxidative stress is involved in pathological processes in the reproductive system that contribute to infertility and poor pregnancy outcomes.

Glutathione, on the other hand, helps preserve the body's antioxidant status. It is particularly present in male and female gametes. One study has shown that it plays an important role in germ cells and is involved in the fertilization process and early development of the embryo [74].


Glutathione is a largely beneficial compound that the human body is able to make on its own. It is also available as an extra, but not all products are created equal. Generally speaking, glutathione in dietary supplement form has low bioavailability, which means that it is poorly absorbed by the intestine and liver and almost cannot reach the bloodstream. Nevertheless, we will see that there are two strategies to counter this poor absorption.

Here are some explanations on the low bioavailability of glutathione provided by supplementation. Our bodies naturally produce glutathione which, when used, is broken down by an enzyme called gamma-glutamyl transferase (GGT). Taking a dietary supplement involves passing the liver barrier before reaching the bloodstream. However, the liver can contain large amounts of the GGT enzyme that breaks down glutathione. As a result, most oral forms of glutathione will not have the desired effects [75].

  • There are then two ways to get around this limitation:
  • Boost synthesis via the precursor N-acetylcysteine (NAC) [76];
  • Opt for a liposomal form.[77]


The two solutions mentioned above are excellent but depend mainly on the budget you have.

Cysteine is effective and inexpensive to increase glutathione levels but you should be aware that it will also be used for other purposes by the body (melanin synthesis, coenzyme A synthesis, zinc assimilation, etc.).

Liposomal glutathione, whose usefulness will be exclusive to increase glutathione levels in the body, is a little more expensive because it uses a powerful technology that allows you to cross the intestinal barrier, but will be faster to restore glutathione levels.
Other nutrients increase glutathione levels. This is the case, for example, with selenium and alpha-lipoic acid. It may therefore be interesting to encourage their contribution.


Selenium is important for maintaining healthy levels of glutathione because it supports the enzyme that uses GSH to neutralize free radicals: glutathione peroxidase. In addition, as we have seen, optimal levels of glutathione, cysteine and selenium can strengthen the intestinal mucosa.

Alpha lipoic acid (ALA)

Lipoic acid (LA), also known as alpha-lipoic acid (ALA), R-lipoic acid or thioctic acid, is a compound containing disulfide, which is present in every cell of the body. It is also one of the main boosters of glutathione levels [78] in addition to playing a key role in producing the energy that the body needs to function.


If you're wondering why your glutathione levels are low, then here are some tips that should help you understand.


The glutathione in your body serves, as we have seen, to detoxify the body and deoxidize it. However, when he encounters a chemical substance such as a drug, he hastens to eliminate it. As such, a study indicates that the therapeutic consumption of paracetamol drastically drops the antioxidant capacity of the body. Paracetamol thus caused a significant reduction in glutathione [79].


Similarly, low levels of glutathione activity are also associated with chronic exposure to chemical toxins and exposure to heavy metals such as cadmium, mercury, etc. [80]. It is therefore important to avoid contact with pesticides, additives, synthetic food colours, household chemicals, ionizing radiation and other pollutants as much as possible.

Of course, alcohol, cigarettes and drugs are toxins that impact glutathione levels [80]. In addition, these addictions are considered pro-oxidant, which gives even more work to this antioxidant already needed in multiple functions of the body. Stopping smoking, drinking alcohol or using drugs will only do you good!


As we all know, stress induces a cascade of harmful events in our body, this has been proven by many scientific studies. Well, here too, stress, anxiety and depression have been associated with low levels of glutathione in the body [28].


If you suffer from a chronic illness or are regularly plagued by infections, it most likely means that your glutathione levels are low. As we have seen before, diseases as diverse as Alzheimer's, Parkinson's, inflammatory digestive diseases, inflammatory diseases of the respiratory voices or cataracts, glaucoma and type 2 diabetes are all associated with low glutathione levels.

Unless your doctor advises otherwise, do not hesitate to supplement in this case, to strengthen your immune system and increase your body's overall antioxidant protection.


An unbalanced diet, devoid of raw materials that allow the body to make or process glutathione will only lower its levels and reduce your body's antioxidant capacity. Do not hesitate to promote a diet rich in vitamin C, selenium, sulfur, etc. We detail this point right after.


Perhaps you already knew, the blue light of our screens (smartphone, tablet, TV, etc.) causes problems with the synthesis of a hormone called melatonin. Indeed, in the evening when the light drops, our body is supposed to produce melatonin to sleep. However, light pollution interferes with the synthesis of this hormone [81]. What does this have to do with glutathione? This same hormone also helps recharge glutathione in our bodies.[82]


Magnesium, known as the king of minerals, is somehow the equivalent of glutathione in the mineral kingdom. It is particularly involved in more than 300 enzymatic reactions of the body. And of course, it participates indirectly in the synthesis of glutathione (co-factor). A study carried out on children with asthma has shown that magnesium exerts antioxidant activity and influences the glutathione redox system [83].


Physical activity is essential to be healthy but be careful not to abuse it. This is because intensive exercise is linked to an increased generation of reactive oxygen species (ROS), the main cause of oxidative stress, due to higher energy demand. However, glutathione plays a very important role in physical exercise by controlling the level of oxidative stress. When the body is overstretched by repeated or too intense workouts, then it's a good idea to supplement with glutathione [84, 85].


To improve the synthesis of glutathione, it is also possible to promote certain types of foods.

According to one study, glutathione deficiency in Covid-19 patients with a severe form may be the result of a decrease in the consumption of fresh vegetables and fruits (especially during the winter and spring seasons).

Indeed, fruits and vegetables contribute more than 50% of dietary glutathione intake, while meats contribute less than 25% [18, 86]. Avocado, asparagus, squash, potatoes, okra, cauliflower, broccoli and raw tomatoes have the highest levels of GSH. Frozen spinach, carrots, beets and vegetables also have moderately high GSH levels [87].

In addition, a number of foods contain the building blocks of glutathione. These can be a great addition to your diet, we can note:

  • Garlic, onion, shallots, chives, leeks and glucosinolates present in cruciferous trees: cabbage, turnips, radishes that stimulate glutathione thanks to their sulfur components. Sulfur is also found in the form of sulfur amino acids in all foods containing protein (eggs, meats, fish, legumes, cereals).
  • Sources of cysteine and methionine may also help increase glutathione levels. Commonly consumed plant foods rich in methionine are corn, sunflower seeds, oats, chocolate, cashews, walnuts, almonds, and sesame seeds. Oats and corn are also rich in cysteine.
  • Foods rich in vitamin C (acerola, strawberries, citrus fruits, papayas, kiwis and peppers for example). Researchers have found that taking vitamin C supplements increases glutathione levels in white blood cells and red blood cells [88, 89].
  • Foods rich in selenium: Brazil nuts, meat, fish, cottage cheese, brown rice. By increasing your selenium intake, you can help maintain or increase your body's supply of glutathione.
Good to know: Corn oatmeal, although low in lysine, has a surprisingly high sulfur amino acid content of about 44 mg/g of protein. For information, chicken contains 41 mg/g.[86].


In this section you will find the dosages used in clinical studies for glutathione and cysteine. Please note, that there is no precise dosage of glutathione and cysteine because there are a multitude of forms and degree of purity of products based on these molecules. It is therefore advisable to consult the opinion of your supplier and follow the seller's instructions. The dosages specified on the product packaging must be respected unless otherwise advised by a specialist.


The dosages used for oral glutathione are usually 1 gram per day in clinical studies [77, 90]. However, it is essential to take into account the fact that it is usually glutathione can be assimilated (non-liposomal) or prescribed for serious disorders such as HIV for example.

 As part of a daily intake, for a fitness cure, sellers generally recommend lower dosages of 150 mg to 300 mg per day of liposomal glutathione. Indeed, since it is absorbed more easily, lower doses are necessary.


 If you've chosen to supplement with N-acetylcysteine, scientific studies typically use dosages ranging from 560 mg to 2400 mg per day [91, 92]. We recommend that you refer to the dosage indicated on the product you have purchased or the one recommended by your doctor.


Glutathione is a generally safe and harmless molecule at recommended doses. However, taking GSH supplements during pregnancy or lactation is not recommended. In this case, it is safer to boost the synthesis via the diet.

In rare cases, consuming glutathione can over-boost your immune system. Always follow the seller's recommendations carefully. Side effects of oral glutathione for 4 weeks (1 g/day) in clinical trials were rare and included [90] flatulence, loose stools and reddening.

Next Post Previous Post
No Comment
Add Comment
comment url