Glutathione

Graded C: several small human trials (IV, intranasal, oral and topical) exist, but none shows a clear clinical benefit; it is not approved in the US.

Strengths: 1,500 mg
Also known as: GSH, Reduced glutathione, L-glutathione, γ-L-glutamyl-L-cysteinyl-glycine, Tathion (Japan)
Molecule: Tripeptide (3 amino acids, unusual γ-linkage)
Formula: C10H17N3O6S
Mol. weight: 307.32 g/mol
CAS: 70-18-8
Sequence: γ-Glu-Cys-Gly

Origin

A tiny peptide every cell makes from glutamate, cysteine and glycine to protect itself from oxidative damage. It is listed in the Japanese Pharmacopoeia and sold there as Tathion.

How it works

Its free thiol group neutralizes reactive oxygen species, recycles other antioxidants and binds toxins for excretion. Lab work suggests it blocks tyrosinase, the melanin enzyme. Whether oral glutathione reaches the blood intact is debated, and no study confirms IV glutathione raises tissue levels for long.

What the research shows

A 21-patient IV pilot in Parkinson's disease found no significant improvement over placebo, and a 45-patient intranasal trial found glutathione no better than placebo. A 6-month oral trial in 54 adults raised blood glutathione 17 to 35%, which fell back after stopping. Small oral and topical skin studies reported lighter skin, but a 2019 review called the evidence inconclusive, and no trial has tested IV glutathione for skin lightening. Tissue uptake and long-term safety of repeated IV exposure are unknown.

Key studies

Hauser et al., Movement Disorders 2009 IV pilot in 21 Parkinson's patients; no significant benefit over placebo.
Mischley et al., J Parkinson's Disease 2017 Intranasal glutathione no better than placebo in 45 patients.
Richie et al., Eur J Nutrition 2015 Oral glutathione raised blood levels 17–35% over 6 months.
Dilokthornsakul et al., J Cosmet Dermatol 2019 Systematic review found skin-lightening evidence inconclusive.

Safety findings

Oral and topical forms were well tolerated in trials. In 2019 FDA documented chills, fever, low blood pressure and a hospital admission after IV glutathione made from supplement-grade powder contaminated with bacterial toxins, and repeated the warning in 2024. The Philippines FDA warned against IV glutathione for skin lightening in 2011.

Regulatory status

No FDA-approved glutathione drug exists; oral glutathione is sold as a dietary supplement (GRAS since 2009). It is in FDA's 503A Category 1 (under evaluation) as of May 2026, so pharmacies may compound it if conditions are met. Not on the WADA Prohibited List, though WADA's method rules (M2.2) restrict large-volume IV infusions outside hospital settings. Status as of October 2026.

Catalog notes

Offered in 1,500 mg; the same molecule as the L-Glutathione listing in a larger vial. A 1,500 mg certificate (lot GLU1500-0803, 99.76%, COA7597) is filed under L-Glutathione; check with support that it applies to this vial. No endotoxin or sterility data are listed.