What is glutathione, and which foods contain it?

Glutathione is a small molecule made of three amino acids, glutamic acid, cysteine and glycine, joined in a chain. The human body makes it itself inside its cells, and it is also present in the cells of the animals and plants we eat. It is not listed in the Thai Reference Daily Intakes (Thai RDIs), so there is no Thai daily value for it.

In short:

• What it is: a tripeptide (three amino acids) with the formula C10H17N3O6S
• Made of: glutamic acid, cysteine and glycine
• Where it comes from: made by the body's own cells; also found in vegetables, fruit and meat
• Two main states: reduced glutathione (GSH) and oxidised glutathione (GSSG)
• Daily value: none in the Thai RDIs
• Watch out for: people who are pregnant or breastfeeding, or who take regular medication, should ask a doctor or pharmacist first

What is glutathione?

Glutathione is a tripeptide, meaning a short chain of three amino acids. A 2023 review by Al-Temimi and colleagues in Metabolites describes it as a low-molecular-weight tripeptide found in living organisms, plants and animals alike. In plant cells it is found in almost every compartment, and in animal cells it is found mainly in the mitochondria.

What is it made of?

The three building blocks are glutamic acid, cysteine and glycine. What makes glutathione unusual is the way they are joined: glutamic acid is linked to cysteine through its gamma-carboxyl group, not through the alpha-carboxyl group used in most proteins. Glycine is attached to the other side of cysteine. The cysteine carries a sulfur-hydrogen group, called a thiol, which is the chemical group that gives glutathione most of its character (Al-Temimi and colleagues 2023). If you would like to know more about amino acids in general, see what are essential amino acids?

Basic facts

Does the body make it by itself?

Yes. A 2013 review by Lu in Biochimica et Biophysica Acta describes glutathione as present in all mammalian tissues and as the most abundant non-protein thiol in them. It is made in the cytosol, the fluid part of the cell, in two steps:

1. The enzyme glutamate cysteine ligase joins glutamic acid and cysteine.
2. The enzyme glutathione synthetase then adds glycine.

Lu notes that the two key factors in how much is made are the supply of cysteine, a sulfur-containing amino acid, and the activity of the first enzyme. The 2023 review in Metabolites gives the concentration inside cells as about 0.5 to 10 mM, depending on the cell type.

How do reduced and oxidised glutathione differ?

Glutathione exists in two main states. Al-Temimi and colleagues (2023) describe them as follows: reduced glutathione (GSH) is the single molecule with a free thiol group, and oxidised glutathione (GSSG) is two GSH molecules joined by a bond between their sulfur atoms, called a disulfide bond. Inside cells, an enzyme called glutathione reductase turns GSSG back into GSH. The same review says that in unstressed cells, about 90% is present as GSH and about 10% as GSSG.

Forms of glutathione

Sources: formulas and weights from PubChem; definitions from Al-Temimi and colleagues (2023).

How was glutathione discovered?

The story took about 40 years to complete. Al-Temimi and colleagues (2023) give this timeline:

Which foods contain glutathione?

Many everyday foods contain some glutathione, because it is present in plant and animal cells. A 2026 review by Bradauskienė and colleagues in Nutrients collected figures from several studies. A selection is below.

Source: Bradauskienė and colleagues (2026), Table 1. The figures come from different studies that used different methods, foods from different countries and different ways of preparing the food, so they show rough ranges, not exact amounts for the food on your plate. The same review says freshly prepared meats generally contain about 5.0–20.0 mg per 100 g.

Which foods are low in glutathione?

A 1992 study by Jones and colleagues at Emory University measured glutathione in the foods on a standard US food questionnaire, bought in the Atlanta area and prepared as they are usually eaten in the United States. They found that dairy products, cereals and breads are generally low in glutathione, fruits and vegetables have moderate to high amounts, and freshly prepared meats are relatively high. The study used American foods, so the figures do not describe Thai dishes directly.

Is glutathione found in durian?

Yes. Research by Panpetch and Sirikantaramas at Chulalongkorn University (2021) describes durian as rich in sulfur-containing compounds such as glutathione and gamma-glutamylcysteine. Glutathione, gamma-glutamylcysteine, cysteine and cysteinylglycine have all been detected in the ripe pulp of the Thai cultivars Chanee and Monthong. These sulfur compounds contribute to the strong smell and flavour of ripe durian, and ripe Chanee has higher levels of cysteine and cysteinylglycine than ripe Monthong.

An earlier study from the same university (Pinsorn and colleagues 2018) analysed the pulp of Chanee and Monthong collected from three orchards in eastern Thailand and annotated 157 metabolites. Differences between cultivars and between harvest years had a bigger effect on the pulp's metabolite profile than where the durian was grown. The same study reported high amounts of gamma-glutamylcysteine and glutathione in the pulp, with glutathione at 158.1 ± 80.4 mg per 100 g of dry weight; because this is per dried pulp, it cannot be compared with the fresh-weight figures in the food table above.

Does cooking or storage change the glutathione in food?

It can. Jones and colleagues (1992) found that frozen foods generally had glutathione levels similar to fresh foods, while other forms of processing and preservation generally caused extensive loss. Bradauskienė and colleagues (2026) also note that processing and cooking often lower the amount, and that the level in a food varies with storage conditions, processing methods and preparation, with heat generally lowering it.

Sources: Jones and colleagues (1992); Bradauskienė and colleagues (2026).

Is glutathione used in food-making?

Yes. Al-Temimi and colleagues (2023) describe research on glutathione in food processing. Both GSH and GSSG have been studied in rice batter for gluten-free bread, where tasters found bread made with GSSG had a less sulfurous smell than bread made with GSH. In wine, glutathione's role in how the smell and taste change during storage has been well documented, regardless of grape and wine variety.

Is there a recommended daily amount of glutathione?

No. Glutathione is not listed in the Thai Reference Daily Intakes (Thai RDIs), which cover nutrients such as protein, vitamins and minerals, so there is no Thai daily value for it. The body makes glutathione itself from amino acids, and it is also present in many ordinary foods, as shown above.

Who should be careful with glutathione?

People who are pregnant or breastfeeding, and children

Bradauskienė and colleagues (2026) note that data from long-term studies of glutathione use in pregnancy and in children are limited, and advise using it with caution and speaking to a doctor.

What has EFSA said about a related form?

In 2026, the European Food Safety Authority (EFSA) assessed S-acetyl glutathione, a chemically made substance that differs from the glutathione in food, as a new food ingredient. The assessment did not cover people who are pregnant or breastfeeding, or children under 10.

People taking regular medication

Anyone who takes regular medication or is under a doctor's ongoing care should tell the doctor or pharmacist about any supplement before using it.

Effects that can occur

Bradauskienė and colleagues (2026) report that the side effects seen in studies of oral glutathione were typically mild, such as gas and bloating.

If you are pregnant, breastfeeding, take regular medication or are under a doctor's care, speak to a doctor or pharmacist before taking dietary supplements.

Dietary supplements are not intended to prevent, treat or cure any disease.