Glutathione
$Endogenous antioxidant system; Route and formulation matter
Glutathione is a tripeptide antioxidant made from glutamate, cysteine, and glycine. It supports redox balance, detoxification, and cellular defense.
Evidence differs by route and biomarker. IV glutathione, oral reduced glutathione, liposomal products, S-acetyl glutathione, and precursors such as NAC/glycine are not interchangeable. Avoid thinking of glutathione as a simple stimulant. Distinguish plasma glutathione, red-blood-cell glutathione, intracellular GSH/GSSG ratio, and clinical outcomes.
Classification details
- Glutathione is an endogenous tripeptide composed of glutamate, cysteine, and glycine.
- Although not a therapeutic peptide in the same sense as many entries, it is included because injectable and IV glutathione are common in peptide-clinic practice.
- Glutathione is a tripeptide antioxidant, not a hormone-like peptide. Route and form matter: reduced GSH, S-acetyl-GSH, liposomal products, topical products, inhaled/nasal, and IV are not interchangeable.
It cycles between reduced (GSH) and oxidized (GSSG) forms. The GSH/GSSG ratio is the meaningful redox readout, not a single value.
- Antioxidant defense: directly scavenges reactive oxygen species and free radicals, protecting DNA, lipids, and proteins.
- Detoxification: in the liver it binds toxins, heavy metals, and pollutants (Phase II conjugation), making them water-soluble for excretion.
- Recharges other antioxidants: regenerates vitamins C and E so they stay active longer.
- Mitochondrial protection: a primary defender of the mitochondria, keeping energy production efficient.
- Melanogenesis inhibition: in skin it inhibits tyrosinase and shifts pigment from darker eumelanin toward lighter pheomelanin.
- Its biology centers on redox buffering, detoxification conjugation, mitochondrial protection, and recycling with NADPH-dependent systems. More glutathione is not always better. Redox balance matters.