Glutathione
Tripeptide of glutamate, cysteine and glycine – key intracellular antioxidant. In cosmetics it promises skin brightening through tyrosinase inhibition and a switch in melanin synthesis.
Evidence by route
Topical application
Topical brightening data come from small Asian studies. The molecule penetrates the stratum corneum poorly, the oxidized GSSG form works better than the reduced one.
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Caution
- Suitable for
- Normal, Dry, Oily, Combination
- Use with caution
- Sensitive
About this ingredient
Glutathione (GSH, L-Glutathione) is a tripeptide of glutamate, cysteine, and glycine. Key intracellular antioxidant – cofactor of glutathione peroxidase, neutralizing peroxide radicals and peroxides. Declines markedly in skin with age and under oxidative stress. Marketing and reality. In Asian countries (Philippines, Thailand) injectable glutathione is marketed as a "skin lightener". FDA and AEMPS have not approved it for this indication – safety and efficacy are not proven. Serious adverse effects from intravenous administration are described: toxic-allergic epidermal necrolysis (Stevens-Johnson Syndrome), thyroid dysfunction, liver failure (Sonthalia 2016). Where applied. Serums and creams (0.1-2%), oral supplements, injections (abroad). In Spain it appears in cosmetics less often than in Asia – the depigmenting trend is preferably addressed via niacinamide + azelaic acid. Topical evidence base. Watanabe 2014 (Clin Cosmet Investig Dermatol) in 60 women over 10 weeks of 2% glutathione: moderate facial pigmentation reduction. Systemic bioavailability of glutathione from supplements is low – gastric enzymes degrade the peptide; topical penetration is poor. Topical safety. CIR confirmed safety at cosmetic concentrations. Irritation and allergic reactions are rare. Pregnancy – use with caution. Systemically contraindicated in pregnancy (especially injectable). Topically at cosmetic concentrations no direct contraindications, but avoid as a precaution. Lactation – no data.
Frequently asked questions
Is Glutathione safe during pregnancy?
Glutathione should be used with caution during pregnancy. Consulting a dermatologist or OB-GYN is advisable.
What skin types is Glutathione for?
Glutathione suits: normal, dry, oily, combination. Use with caution in: sensitive.
What is Glutathione and what does it do in cosmetics?
Tripeptide of glutamate, cysteine and glycine – key intracellular antioxidant.
What's the INCI name for Glutathione?
The INCI name is Glutathione. It may also appear as: L-Glutathione.
See Glutathione in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
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