L-glutathione 2018-02-14T13:56:21+00:00

What is Glutathione?

On this page you will learn

  1. Why Glutathione is a powerful antioxidant,
  2. About the many health benefits that it provides,
  3. Why taking Glutathione supplements does not work (and why you need to take Cysteine instead),
  4. What simple things you can do to maximise your Glutathione levels.

Glutathione is a protein that is found inside every cell of the human body, with the highest concentrations found in the liver. As a sulfuric Tripeptide it consists of the following three amino acids Glutamic acid, L-cysteine and L-glycine.

Glutathione was first discovered in 1888, but it was not until 1984 that its metabolism in the body began to be thoroughly investigated.

Glutathione acts as a powerful antioxidant and detoxifier that protects cells from free radicals and oxidative stress and boosts the immune system.

The levels of glutathione in the cells of the human body begin to decline after the age of twenty.

Additional supplementation of L-Cysteine enables the body to produce more Glutathione.

This in turn enables the body to reuse oxidised vitamin E and vitamin C when combined with the enzyme glutathione peroxidase.

The Key Benefits of Glutathione

Decreased Glutathione levels have been linked to a number of age-related diseases, including Alzheimer’s and macular degeneration. A 2004 study by the University of Alabama found that the red blood cells in male Alzheimer’s patients showed a significant lack of glutathione 1.

glutathione and heart health

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A study of patients with heart disease found that the lower the levels of glutathione, the more likely they were to have a heart attack 2.

Glutathione’s strong antioxidant properties make it suitable as a supplement particularly cases of disadvantageous cell growth such as cancer tumors and lipomas. Glutathione is not able to cure cancer, but several studies suggest that the growth of new cancer cells may be reduced.  Some doctors therefore recommend its supplementation to treat cancer, as it increases the effectiveness of chemotherapy drugs and reduces their toxicity3.

Glutathione has also been used to treat Parkinson’s disease, sickle cell anaemia, idiopathic pulmonary fibrosis and poisoning, as it is able to detoxify the body of heavy metals such as mercury.

Glutathione is able able to positively influence the quality of sperm in men. This effect is achieved by the lowering of blood pressure in cases of diabetic patients, decreasing oxidative stress on the sensitive sperm cells and therefore minimising damage to their DNA cargo4.

It is therefore recommended that couples, who are trying to conceive supplement various micro-nutrients. In particular, they should consume N-Acetyl-Cysteine (NAC), which is used in the body to produce L-glutathione.

READ how L-glutathione boosts male fertility.

To effectively increase male fertility, the aspiring father should also look to consume other scientifically proven nutrients such as Arginine, Carnitine and Pine Bark Extract. The most efficient and affordable to take a combination supplement with several proven male fertility micro-nutrients. These will positively affect sperm count, motility and morphology simultaneously.

the best male fertility supplements with Cysteine (NAC) and L-glutathione

Compare the best male fertility supplements with amino acids such as Cysteine (NAC) and L-glutathione

Glutathione has also been used to treat asthma and airway restriction when used as an inhalant. A 2010 study by the University of Utrecht found that it prevents early asthmatic reaction and airway hyper-responsiveness5.

Psychiatric illnesses, including bipolar disorder, schizophrenia and depression have been linked to low levels of glutathione as without its antioxidant abilities in the brain, oxidative stress can occurs there6.
It is generally advisable to build a high level of Glutathione in ones blood to protect the body from oxidation (damage to the tissue by free radicals). Oxidative stress plays significant roles in cancer, but also in Artherosclerosis, Arthritis and Cataract.

How Does Glutathione Work?

genetics are important in the aging process

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Glutathione is the only intracellular antioxidant found, which means it acts inside the cells. As such it is able to maintain their health and performance and resist disease by neutralising free radicals and keeping other antioxidants, including Vitamin C and E, in their active form. It also helps the liver to process toxins, helps with DNA and protein synthesis, and regulates both the nitric oxide cycle and the metabolism of iron.
The levels of glutathione in patients with serious diseases such as AIDS and cancer have been found to be very low. Studies are on-going into the reasons for this, but many scientists believe there is a link between low glutathione levels and cell death7.
Several studies of centenarians (humans who have lived to be over 100 years old) in various countries, including Poland, Italy and Denmark, have found very high levels of glutathione in their cells.

How to Best Consume Glutathione

Most recommended for supplementation are combinations of the amino acids L-cysteine and L-glutamine, because oral consumption of L-glutathione is not conclusively researched. In order to maximise the oxidative effect, these amino acids should taken together with selenium, zink and magnesium.

green vegetables include lots of glutathione

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Glutathione occurs naturally in many fresh vegetables, fruits and red meat (beef, mutton and lamb), and a healthy diet can help to maintain levels and make it possible for the body to continue to synthesise it.
Particularly useful for this are vegetables that contain high amounts of sulphur, including cabbage, broccoli, garlic, kale and cauliflower.
Many of the benefits are lost when food is cooked, however. Certain nutritional supplements, such as pine bark extract, alpha lipoic acid, milk thistle and grape extract can also increase glutathione levels.

While there are many glutathione tablets and supplements on the market, a 1992 study by the University of Bern, Switzerland, found that oral administration of glutathione capsules does NOT raise glutathione levels
Hagen TM, Wierzbicka GT, Sillau AH, et al
Because it is a protein, a large amount of ingested glutathione is broken down by the gut and eliminated before reaching the cells8. Glutathione is best absorbed by the body when given by intravenous infusion, which is often done in cases of severe disease. This is of course impractical in everyday life.

The most effective way to increase glutathione levels, along with eating a healthy diet and taking regular exercise, is to ingest a precursor. This contains the molecules needed to stimulate the body to produce glutathione, rather than the protein itself.

One such micro-nutrient is N-Acetyl-Cysteine, also known as NAC. This has been used for many years to break up mucus in the lungs in patients suffering from cystic fibrosis, asthma and bronchitis, and is often used by HIV patients to boost their immune system.

milk increases glutathione

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Unbonded L-cysteine, or free cysteine, is destroyed in the gut by enzymes and pepsins, but if the cysteine molecules are bonded, it will be absorbed into the bloodstream and enter cells. There it can bond with glycine and glutamate to make more glutathione.

This bonded cysteine is also found in human breast milk, and can be replicated with raw cow’s milk in the form of undenatured whey protein.

Large doses of NAC are often given in cases of acetaminophen (Tylenol) overdose to prevent liver failure. Daily doses of 500mg or more of Vitamin C have also been found to increase production of glutathione9.

If not synthesised in the body L-glutathione is produced by fermentation,  which is the industrial processing of plant based foods via enzymes.

L-glutathione can be stored easily for up to five years in dry conditions, room temperature and protected from sunlight.

happy couple kissing in bed

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While glutathione is a naturally occurring molecule that is found inside every cell of the body, levels decrease with age and low levels can cause many serious diseases. It is one of the most powerful antioxidants in the body as it is the only one that is intracellular.
It has even been found to act as an antioxidant to other antioxidants as it has the ability to maximise the activity of Vitamin C, Vitamin E and CoQ10. While a healthy diet and lifestyle can help to slow the body’s decline, supplementing this with glutathione precursors can help to stimulate the body to produce more and thus maintain health and slow the aging process.


  1. “Glutathione metabolism during aging and in Alzheimer disease http://www.ncbi.nlm.nih.gov/pubmed/15247041′
  2. “Blankenberg, Stefan, et al. Glutathione peroxidase 1 activity and cardiovascular events in patients with coronary artery disease. New England Journal of Medicine, Vol. 349, October 23, 2003, pp. 1605-13”
  3. “Smyth JF, Bowman A, Perren T, et al. Glutathione reduces the toxicity and improves quality of life of women diagnosed with ovarian cancer treated with cisplatin: results of a double-blind, randomized trial. Ann Oncol 1997;8:569-73′
  4. “Lenzi A, Culasso F, Gandini L, et al. Placebo-controlled, double-blind, cross-over trial of glutathione therapy in male infertility. Hum Reprod 1993;8:1657-62”
  5. “http://www.ncbi.nlm.nih.gov/pubmed/20228417”
  6. “Gawryluk, JW; Wang, JF; Andreazza, AC; Shao, L; Young, LT (2011). “Decreased levels of glutathione, the major brain antioxidant, in post-mortem prefrontal cortex from patients with psychiatric disorders”. The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP) 14 (1): 123–30.doi:10.1017/S1461145710000805. PMID 20633320″
  7. “Glutathione, oxidative stress and aging, Age, Vol. 19, 129-139, 1996 http://link.springer.com/article/10.1007%2FBF02434082”
  8. “Hagen TM, Wierzbicka GT, Sillau AH, et al. Fate of dietary glutathione: disposition in the gastrointestinal tract. Am J Physiology 1990;259(4Pt1):G530-5)
  9. “Johnston, CS, et al. Vitamin C elevates red blood cell glutathione in healthy adults. American Journal of Clinical Nutrition, Vol. 58, July 1993, pp. 103-05”