Glutathione

Glutathione (abbreviated to GSH) is a tripeptide with a molecular weight of approximately 307.32 g/mol. What makes it special is the sulphur-containing cysteine group: this makes the molecule reactive and enables it to donate electrons.

Mechanism of action under investigation

Glutathione is often referred to as the cell’s ‘master antioxidant’. Research is being carried out to investigate how it neutralises reactive molecules (free radicals) and how it contributes to the redox balance — the equilibrium between oxidation and reduction within the cell. Its role in detoxification processes is also a subject of research. In this context, glutathione alternates between a reduced form (GSH) and an oxidised form (GSSG); this ratio is used in research as a measure of oxidative stress.

These mechanisms are derived from laboratory and cell-based research and describe the research context; they do not represent proven health effects in humans.

The fact that glutathione is a molecule produced naturally by the body makes it a particularly useful reference in redox biology: researchers know exactly what role it plays in nature and can compare their experimental observations with this.

Glutathione is one of the most widely studied endogenous antioxidants and plays a central role in research into oxidative stress. As it occurs naturally in cells, it is an important reference molecule in redox biology.

• Research focus: neutralisation of free radicals.
• Research focus: the redox balance (GSH/GSSG ratio).
• Research focus: detoxification and cellular protection.

Status and context

As a research compound, glutathione is supplied exclusively for laboratory and research purposes; in this form, it is not an authorised medicinal product. Although glutathione is a naturally occurring substance in the body, laboratory findings do not provide any indication of its applications in humans. A pure, well-characterised starting material is essential to ensure that redox measurements remain reliable and reproducible.

The ratio between the reduced and oxidised forms is one of the most commonly used measures of oxidative stress in cell and tissue research. A pure starting material is crucial in this context, as impurities or premature oxidation directly affect the measurement.

As glutathione oxidises quickly, the method of storage is just as crucial to obtaining a reliable measurement as the purity itself.

Glutathione is supplied as a lyophilised powder and reconstituted in the laboratory using bacteriostatic water. The steps below describe only the laboratory procedures for research purposes.

1. 1Allow the vial and the bacteriostatic water to reach room temperature.
2. 2Wipe the rubber stoppers of both vials with an alcohol wipe.
3. 3Allow the bacteriostatic water to run slowly down the side of the vial; do not direct it straight onto the powder.
4. 4Gently swirl the vial until everything has dissolved; do not shake.
5. 5Store the solution in the fridge and label it with the date and batch number.

You can find supplies such as bacteriostatic water, insulin syringes and alcohol wipes under ‘Lab & Accessories’. This is a laboratory instruction and does not constitute dosage advice for consumption.

Working with a sensitive molecule

Glutathione is susceptible to oxidation: when exposed to air, the reduced form (GSH) can convert to the oxidised form (GSSG). You should therefore work quickly, minimise exposure to air and light, and store the solution in a cool place immediately. Make a note of the preparation time so that you can estimate the rate of oxidation between experiments.

Minimise oxidation

Prepare only the amount you will use in the short term and seal the vial tightly; this will help you keep the concentration of reduced glutathione (GSH) as high as possible during your experiment.

Store glutathione in a cool, dark place; the molecule is sensitive to oxidation, heat and moisture.

Practical storage tips

• Powder form: store in the freezer (-20 °C) to ensure long-term stability.
• After reconstitution: store in a cool place (2–8 °C) and use as soon as possible.
• Minimise exposure to air and light to prevent oxidation.
• Make a note of the reconstitution date and the batch number.

Cool, airtight and dark storage is essential to preserve the purity and reduced form.

Check the solution before use and work in an airtight environment as far as possible to minimise oxidation.