Ingredient

Glutathione

L-Glutathione GSH Reduced Glutathione

What it is

A naturally occurring tripeptide antioxidant (glutamate-cysteine-glycine) found in the body, popular in brightening formulas for its antioxidant reputation.

How it works

As an antioxidant it can help neutralize reactive oxygen species within the formula and on skin; its topical skin-lightening efficacy is far less established than the more widely studied oral/IV glutathione whitening use, since the intact peptide penetrates skin poorly.

What it does

Skin conditioning Antioxidant

Concerns to know

Well tolerated

No significant safety concern is reported for this ingredient as used in cosmetics.

Evidence at a glance

Generally well tolerated

Recognised for a well-studied benefit.

Why this rating

Well tolerated

Topical glutathione has not been associated with notable irritation or sensitization in cosmetic formulation use; this is distinct from oral/IV glutathione 'skin-whitening' use, which carries separate safety concerns and greater regulatory scrutiny in some countries, and topical pigmentation efficacy remains poorly substantiated due to limited skin penetration of the intact peptide (PubChem CID 124886).