Glutathione (GSH) is the tripeptide γ-L-glutamyl-L-cysteinylglycine. Its glutamate is linked through the side-chain γ-carboxyl rather than the usual α-carboxyl, which protects it from most peptidases. It is the most abundant low-molecular-weight thiol in animal cells and is synthesized in two ATP-dependent steps by glutamate–cysteine ligase and glutathione synthetase.

The cysteine thiol takes part in reversible redox chemistry, cycling between reduced GSH and the disulfide-linked oxidized form (GSSG). GSH is the cosubstrate for glutathione peroxidases and glutathione S-transferases, and the GSH/GSSG ratio is widely used as an indicator of cellular redox state. Reversible S-glutathionylation of protein cysteines is studied as a redox-signalling modification.

Glutathione is used in redox biology, enzyme assays for GST and peroxidase activity, thiol chemistry and cell culture work. This product is the reduced free acid. It dissolves freely in water but its thiol oxidizes in air, so solutions should be prepared fresh.

Research use only. This material is sold for in-vitro laboratory research and development purposes exclusively. It is not a drug, food, or dietary supplement, has not been evaluated by the FDA, and must not be used in humans or animals.