Glutathione: dosage in studies
Not a recommendation, not treatment guidance. This page shows only what published human studies used, with sources. This site does not say how much anyone should use of any substance. The content and quality of a product bought online or as a supplement are not controlled like a medicine's.
In the studies in the table, glutathione was taken by mouth. Daily amounts were 250-1,000 mg, and use lasted from three weeks to six months [1, 2, 3, 4]A [5]B.
Participants were healthy adults, men with obesity, some of whom had type 2 diabetes, and people with fatty liver disease [1, 2, 3, 4]A [5]B.
Doses used in studies
| Study | Participants | Dose | Frequency | Duration | Source and level |
|---|---|---|---|---|---|
| Allen 2011 | 40 healthy adults | 500 mg by mouth | Twice a day | 4 weeks | [1]A |
| Richie 2015, lower dose | 54 non-smoking adults (two dose groups and a placebo group) | 250 mg a day by mouth | Daily | 6 months | [2]A |
| Richie 2015, higher dose | 54 non-smoking adults (two dose groups and a placebo group) | 1,000 mg a day by mouth | Daily | 6 months | [2]A |
| Arjinpathana 2012 | 60 healthy medical students | 500 mg a day by mouth, split into two doses | Twice a day | 4 weeks | [3]A |
| Søndergård 2021 | 20 men with obesity, 10 of them with type 2 diabetes | 1,000 mg a day by mouth | Daily | 3 weeks | [4]A |
| Honda 2017 | 34 people with fatty liver disease (29 completed the study) | 300 mg a day by mouth | Daily | 4 months | [5]B |
Evidence levels: A = randomised human trial or meta-analysis · B = observational human study or case series · C = animal study · D = cell or laboratory study · E = not peer-reviewed
Notes
All amounts in the table were taken by mouth. The studies were small, with 20-60 participants, and lasted six months at most [1, 2, 3, 4]A [5]B.
Honda 2017 was an open study without a control group, and before glutathione the participants had changed their diet and exercise for three months. Its result is therefore weaker evidence than placebo-controlled results [5]B.
What points the other way or is uncertain
In Allen 2011, 500 mg twice a day for four weeks did not change oxidative stress markers or glutathione levels in red blood cells [1]A. In the six-month Richie 2015 trial, by contrast, body stores of glutathione increased [2]A.
In a study of seven healthy volunteers, a single dose of glutathione did not raise blood glutathione over 270 minutes. According to the authors, a single dose of 3 g cannot raise blood glutathione to a clinically meaningful extent [6]B.
In a randomised trial in children aged 2-10 with cystic fibrosis, glutathione by mouth did not affect growth or inflammation markers over 24 weeks [7]A.
Read the research yourself: sources
- Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers. J Altern Complement Med. 2011;17(9):827-833. PMID 21875351
- Richie JP Jr, Nichenametla S, Neidig W, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr. 2015;54(2):251-263. PMID 24791752
- Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. J Dermatolog Treat. 2012;23(2):97-102. PMID 20524875
- Søndergård SD, Cintin I, Kuhlman AB, et al. The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial. Appl Physiol Nutr Metab. 2021;46(9):1133-1142. PMID 33740389
- Honda Y, Kessoku T, Sumida Y, et al. Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study. BMC Gastroenterol. 2017;17(1):96. PMID 28789631
- Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. Eur J Clin Pharmacol. 1992;43(6):667-669. PMID 1362956
- Bozic M, Goss CH, Tirouvanziam RM, et al. Oral Glutathione and Growth in Cystic Fibrosis: A Multicenter, Randomized, Placebo-controlled, Double-blind Trial. J Pediatr Gastroenterol Nutr. 2020;71(6):771-777. PMID 32960827
Sources checked in PubMed on 12 Oct 2026. All amounts in the table are from the study abstracts.
Content is general information about research, not medical advice. If you have symptoms, contact a healthcare professional.