Glutathione (GSH): Scientific Profile

Publicado el 28 de diciembre de 2025 · Actualizado el 18 de septiembre de 2026

Reduced L-Glutathione (GSH; CAS 70-18-8), an endogenous thiol tripeptide (γ-Glu-Cys-Gly) and the main intracellular antioxidant. Cofactor of glutathione peroxidase and substrate of glutathione-S-transferase. Reagent for research.

Glutathione (GSH; full name gamma-L-glutamyl-L-cysteinyl-glycine; English name Glutathione; CAS 70-18-8) is a naturally occurring tripeptide present in practically all cells. With the molecular formula C10H17N3O6S and a molecular weight of approximately 307.32 g/mol, it is composed of three amino acids —glutamic acid, cysteine and glycine— joined in a peculiar way: the bond between glutamate and cysteine is a gamma-peptide bond (through the carboxyl group of the glutamate side chain), which confers resistance to conventional peptidases. The thiol group (-SH) of the cysteine residue is the chemically active center of the molecule and the basis of its redox function.

From a biochemical standpoint, Glutathione is the main non-protein thiol antioxidant of the intracellular environment. It exists in a dynamic equilibrium between its reduced form (GSH) and its oxidized disulfide form (GSSG), and the GSH/GSSG ratio is one of the most widely used indicators of cellular redox state. In neutralizing reactive oxygen species, the enzyme glutathione peroxidase uses GSH to reduce peroxides, generating GSSG, which in turn is regenerated to GSH by glutathione reductase at the expense of NADPH. This redox cycle maintains the reducing environment of the cytosol and protects proteins, lipids and nucleic acids against oxidative damage in research models.

Glutathione also participates in biotransformation and conjugation processes. Through the glutathione S-transferases, its thiol group is conjugated with electrophilic compounds and xenobiotics, a step characteristic of phase II reactions that facilitates their subsequent elimination. It also takes part in nitric oxide homeostasis through the formation of S-nitrosoglutathione, in the recycling of other antioxidants and in the regulation of signaling pathways sensitive to redox state. Because of these functions, GSH is a central reagent in the study of oxidative stress and cellular detoxification mechanisms.

In the field of research, Glutathione is used as a tool for the study of antioxidant defense, redox balance, mitochondrial and hepatic function, and phase II conjugation mechanisms in cellular models. It is a common standard in antioxidant capacity assays, in the measurement of the GSH/GSSG ratio as a marker of oxidative stress and in the study of the enzymes of glutathione metabolism.

Glutathione is supplied as a lyophilized powder for reconstitution. Because it is a molecule with a thiol group susceptible to oxidation, frozen storage protected from light, air and moisture is recommended, along with reconstitution using the sterile diluent indicated in the protocol immediately before use. This product is offered exclusively as a research reagent (research use only): it is not intended for the diagnosis, prevention or treatment of any disease, nor for human or veterinary consumption.