Glutathione: research, uses and evidence

Glutathione is the main intracellular antioxidant, a tripeptide made by nearly every cell. A six-month randomized trial found that daily oral glutathione increased body stores in blood and cheek cells. Its use as an injection for skin lightening is widespread in some countries but poorly supported and not FDA-approved.

Structure

γ-Glu-Cys-Gly. The glutamate is linked through its side-chain (gamma) carboxyl rather than the usual alpha peptide bond.

How it works

The cysteine thiol of glutathione neutralizes reactive oxygen species and is regenerated by glutathione reductase. It also conjugates toxins for elimination and shifts melanin synthesis from dark eumelanin toward lighter pheomelanin.

Research use cases

Areas where Glutathione has been studied. Inclusion here does not mean it works for that purpose.

Oxidative stress
Liver detoxification pathways
Skin pigmentation

What the research found

Oral supplementation

In 54 adults, 250 or 1,000 mg daily oral glutathione for six months raised glutathione levels in blood, red cells and buccal cells in a dose-dependent way, reversing on stopping.¹

Safety and open questions

Oral use is well tolerated. Intravenous use for skin lightening has been linked in regulatory warnings to adverse reactions and contamination concerns.

Regulatory status

Dietary supplement ingredient. Injectable glutathione for skin lightening is not FDA-approved, and the FDA has warned about unapproved injectable products.

Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.

Glutathione: common questions

Does glutathione lighten skin?

Small trials have reported modest effects, but evidence is limited and inconsistent, and no regulator in the US has approved it for that purpose.

Is Glutathione approved for human use?