Glutathione is a tripeptide of glutamate, cysteine and glycine, present in essentially every cell and typically the most abundant intracellular antioxidant, reaching millimolar concentrations.
The gamma linkage
One structural detail explains much of its behaviour. The bond between glutamate and cysteine is a gamma-peptide bond — formed at the side-chain carboxyl rather than the alpha-carboxyl used in ordinary peptide bonds.
Standard peptidases cannot cleave it. That is why glutathione survives in the cytosol long enough to function as a redox buffer, and why it is synthesised enzymatically inside cells rather than assembled on ribosomes like a normal peptide.
The redox couple
Glutathione cycles between a reduced form (GSH) and an oxidised disulphide dimer (GSSG). Glutathione peroxidase uses GSH to reduce peroxides; glutathione reductase regenerates GSH from GSSG using NADPH.
The GSH/GSSG ratio is the standard readout of cellular redox state, which is why glutathione appears constantly in oxidative-stress research — often as the measurement rather than the intervention.
Research context
Also central to phase II detoxification, where glutathione S-transferases conjugate GSH to electrophilic compounds for excretion.
Supplied lyophilised. See our reconstitution protocol for handling technique and diluent selection.
Every batch ships with a third-party certificate of analysis. View Glutathione and its current COA.
Research use only
Isla Longevity supplies this compound for laboratory research use only. It is not approved by the FDA for human or veterinary use and is not for human consumption. This article summarises published research and is not medical guidance.
