GlutathioneIs glutathione safe?
Short answer
Taken by mouth, it caused few problems in trials. In a 4-week skin trial, both glutathione and placebo were very well tolerated.[1] A review of skin studies found some adverse events, none of them serious.[2] EFSA judged S-acetyl glutathione safe for adults at up to 300 mg a day. Its assessment did not cover pregnant or breastfeeding women or children under 10.[3]
Other forms carry more risk. In a study of 8 people with mild asthma, inhaled glutathione narrowed the airways.[4] A 2025 review advised against glutathione into a vein for skin lightening, because it did not work and caused side effects.[5] In 2026, the FDA reported at least 30 people with fever, chills, signs of shock and other reactions after glutathione injections made from supplement-grade glutathione.[6]
Ask a doctor or pharmacist first if you are pregnant or breastfeeding, or if you have asthma and plan to inhale glutathione.[3][4]
Sources (6)
- Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. Arjinpathana N, Asawanonda P J Dermatolog Treat, 2012. PMID 20524875
- The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. Dilokthornsakul W, Dhippayom T, Dilokthornsakul P J Cosmet Dermatol, 2019. PMID 30895708
- Safety of S-acetyl glutathione as an novel food pursuant to Regulation (EU) 2015/2283. Turck D, Bohn T, Cámara M, Castenmiller J, De Henauw S, Jos Á, et al. EFSA J, 2026. PMID 42683004
- Nebulized glutathione induces bronchoconstriction in patients with mild asthma. Marrades RM, Roca J, Barberà JA, de Jover L, MacNee W, Rodriguez-Roisin R Am J Respir Crit Care Med, 1997. PMID 9279219
- Glutathione as a skin-lightening agent and in melasma: a systematic review. Sarkar R, Yadav V, Yadav T, P J, Mandal I Int J Dermatol, 2025. PMID 39444151
- FDA reminds compounders not to use dietary supplement grade glutathione for injectables. US Food and Drug Administration, 2026. www.fda.gov
More about glutathione
What is glutathione?Is glutathione absorbed when taken by mouth?Does glutathione work?Do glutathione levels fall with age?Does glutathione lighten skin?Does glutathione help the liver?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.