GlutathioneIs NAC better than glutathione?
Short answer
It depends on the goal. NAC (N-acetylcysteine) supplies cysteine, one of the main factors that decide how much glutathione cells make.[1][2] A 3-week crossover trial in 20 people with metabolic syndrome compared sublingual glutathione, plain glutathione by mouth and NAC. Sublingual glutathione raised plasma glutathione more than plain glutathione by mouth, and the authors judged it better than both plain glutathione by mouth and NAC.[3]
In Parkinson's disease, a 2026 review found that NAC improved symptoms, while glutathione given through the nose did not. It called the evidence for both early.[4] In cystic fibrosis, NAC by mouth probably improved lung function after 6 months.[5]
Sources (5)
- Glutathione metabolism and its implications for health. Wu G, Fang YZ, Yang S, Lupton JR, Turner ND J Nutr, 2004. PMID 14988435
- Regulation of glutathione synthesis. Lu SC Mol Aspects Med, 2009. PMID 18601945
- Effects of N-acetylcysteine, oral glutathione (GSH) and a novel sublingual form of GSH on oxidative stress markers: A comparative crossover study. Schmitt B, Vicenzi M, Garrel C, Denis FM Redox Biol, 2015. PMID 26262996
- The role of N-acetylcysteine and glutathione in the management of Parkinson's disease: a systematic review of oxidative biomarkers and clinical outcomes. Mohammed I, Nankya Y, Hong UT, Kan A, Abdelhafid AM, Latunde-Dada GO Amino Acids, 2026. PMID 41874704
- Antioxidant supplementation for lung disease in cystic fibrosis. Ciofu O, Smith S, Lykkesfeldt J Cochrane Database Syst Rev, 2019. PMID 31580490
More about glutathione
What is glutathione?Is glutathione absorbed when taken by mouth?Does glutathione work?Do glutathione levels fall with age?Is glutathione safe?Does glutathione lighten skin?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.