What is glutathione?
An antioxidant and detoxifying protein
Glutathione is a protein called “tripeptide”, because it is mainly composed of three amino acids: glutamic acid, cysteine, glycine.
This protein helps detoxify heavy metals and slow cellular aging. These properties make it an essential ally for our health and our skin.
In the diet
This protein is produced in our cells, but it is also found concentrated in certain fruits and vegetables, notably asparagus, avocados, spinach, papaya, strawberries, orange or lemon.
A study has shown that the Mediterranean diet is effective at increasing glutathione levels in the body.
This diet consists of cereal products, legumes, colorful fruits and vegetables, olive oil, oily fish and eggs.
Vitamin C increases the synthesis and assimilation of glutathione. You can find vitamin C in berries, citrus fruits, all types of cabbage, broccoli, and aromatic herbs such as parsley.
What are the benefits of glutathione?
Antioxidant and anti-aging properties
Glutathione is the ultimate anti-rust of our body.
This compound is capable of trapping the “oxidizing” chemical molecules called free radicals, which are responsible for the aging of our cells, as shown by this study.
A person’s ability to produce it varies, and genetic predispositions exist.
People exposed to oxidative stress (pollution, pesticides, an unbalanced diet, chronic stress) have an increased need for this protein.
In addition to its antioxidant effects that help combat the body’s overall aging, it also has anti-aging properties, particularly on skin tissue.
An experimental study showed that oral intake of glutathione for three months significantly reduced wrinkles. The skin was also more elastic.
Finally, several studies have observed a link between its low level and the occurrence of many diseases: cancer, diabetes, cardiovascular diseases, brain disorders (Alzheimer’s or Parkinson’s).
A detoxifying effect on the liver
Glutathione is particularly concentrated in the liver, where it plays a major role in detoxification.
It thus contributes to the elimination of pollutants, medications, heavy metals, and pesticides.
How? Glutathione, aided by other molecules, can bind to toxins to transform them into water-soluble compounds, making them easier to eliminate from the body through urine.
Numerous studies are underway on the use of glutathione in liver diseases (hepatitis, alcoholism, cancer): this molecule actively helps protect cells against oxidative damage and limits the accumulation of toxins.
A role in immunity
Glutathione plays a role in the functioning of our innate immunity.
Thus, a clinical study showed that a two-week glutathione supplementation led to a 60% increase in lymphocyte production, the agents responsible for the body’s defense reactions against foreign substances.
Its administration was also followed by a significant increase in the production of so-called “killer” molecules, capable of eradicating cancer cells or cells infected by a virus.
Its superpowers are therefore being studied as a complementary treatment for many diseases such as the flu, hepatitis C, or HIV.
This study indicates that a high dose improves immune function and the body’s antiviral activity.
In what form?
In capsules
Conveniently, it is the most commonly found form on the dietary supplement market.
This study shows that the oral route is not the most effective form, because glutathione is rapidly broken down by the stomach’s digestive enzymes.
Absorption and product quality vary greatly between brands.
I recommend opting for enteric-coated capsules. This form protects glutathione from degradation in the stomach.
Moreover, this form concentrates high amounts of glutathione and thus allows for a sufficient daily dosage.
It’s also a good compromise between quality and price.
Absorption is adequate and enteric-coated capsules remain cheaper than other well-absorbed forms, because production is easier.
In sublingual tablets
These are tablets to be placed under the tongue. This form allows for easy absorption, as shown by this study.
The sublingual route avoids passage through the stomach and glutathione reaches the bloodstream directly.
However, the amount of glutathione in sublingual tablets is generally insufficient to expect a significant effect, and the tablets contain additives, including sugars or flavorings, which should be avoided!
In liposomal form
This is the most active form.
Liposomes are small droplets enclosed in fat capsules, to protect the active ingredients from degradation in the stomach.
The liposomal form provides excellent absorption because glutathione is distributed to all cells.
A study confirms that daily administration of liposomal GSH can increase glutathione reserves and thus affect innate immunity and oxidative stress.
Because the liposomal form is more complex to produce, the price is generally higher than other forms.
What criteria should be taken into account ?
A dietary source remains the best source of glutathione, because absorption is optimal.
The effectiveness of dietary supplements has not yet been clearly demonstrated, because glutathione must enter the cells to be fully active.
Therefore, it is essential to carefully choose your supplementation in order to optimize absorption.
1. Different forms of glutathione
In our bodies, it is found in an oxidized form or in a reduced form. Both are essential to the balance of our cells.
In dietary supplements, it is produced by a natural process, fermentation.
This involves bacteria or yeasts that develop in cane sugar. The result is an oxidized form of glutathione (GSSG) or a reduced form (GSH).
Only the reduced GSH form is useful in dietary supplements.
Indeed, this is the form that decreases with age: you should find the label “GSH” or “reduced” on the product packaging.
And oxidized glutathione? Less absorbable by the body, I do not recommend it due to the lack of available studies. If you find the mention “GSSG” or “glutathione” without further information on the box, move on!
2. Combinations of compounds
- Vitamin C
Some dietary supplements combine it with other compounds that stimulate its internal production, notably vitamin C.
This vitamin also has an antioxidant effect, it increases blood glutathione levels and makes it absorbable in the digestive tract.
This study has thus shown that supplementation with 500 mg of vitamin C maintains blood glutathione concentrations while improving antioxidant function.
You will thus find a synergy of several antioxidant compounds (vitamin E, selenium) in some products.
Nevertheless, always check that the daily dose of glutathione is sufficient to have a significant effect.
- N-acetylcysteine
Another association with glutathione, NAC, for N-acetylcysteine. This molecule is a specific form of L-cysteine, one of the three amino acids that make up glutathione.
This L-cysteine may be insufficient in the body, and may thus slow down glutathione production.
Unstable, L-cysteine is formulated as NAC to be sufficiently absorbed by the body. You will find the term NAC in the list of ingredients.
- Milk thistle
Glutathione can also be found associated with milk thistle, a plant containing an active compound called silymarin.
This compound promotes the synthesis of L-cysteine in the liver.
3. Glutathione dosage
There is not enough scientific evidence to determine the usual dosage for supplementation.
The appropriate dose will depend on several factors and the indications for taking glutathione.
A daily dose of at least 300 mg is recommended to achieve a sufficient effect.
Intakes can go up to 600 mg in certain conditions, following medical advice.
A capsule generally contains an average of 50 mg of glutathione, requiring multiple doses to reach the recommended dosage.
Does consuming glutathione pose a danger ?
Do not exceed 400 mg per day without medical advice, and keep treatment courses short, to a maximum of 3 months.
The medium- and long-term effects of glutathione supplementation are not well known.
There are no known contraindications to supplementation; however, its use in pregnant or breastfeeding women requires the treating physician’s approval.
In summary
To be sure to choose glutathione of quality, check:
- The form of the supplement: the liposomal form is the most active (but also the most expensive)
- The form of glutathione : choose the reduced GSH form ;
- Combinations of compounds : vitamin C helps stimulate internal glutathione production ;
- Dosage: a daily dose of minimum 300 mg is recommended, choose a high average glutathione content
