"Glutathione-Boosting" Foods and Supplements: Sulforaphane, Selenium and Whey Claims
Can sulforaphane from broccoli, selenium or whey protein raise glutathione? What the trials we read measured, what they did not show, and the safety limits.
Content last updated . This page has not been medically reviewed.
Claims versus trials
| Item | What the sources we read found | Label |
|---|---|---|
| Sulforaphane (from broccoli sprouts) | A placebo-controlled dose-escalation trial found that sulforaphane from broccoli sprout homogenate raised RNA expression of antioxidant "phase II" enzymes, including a glutathione enzyme, in nasal cells. It measured gene activity in the nose, not blood glutathione or symptoms. [2] | Promising but limited |
| Sulforaphane precursor in capsules | A 2-month placebo-controlled trial in 52 Japanese men with fatty liver found lower liver blood tests and a lower urinary oxidative-stress marker. [3] The marker is not glutathione, the trial was small, and men only. | Promising but limited |
| Selenium | A meta-analysis of 10 randomized trials (published in Chinese, 2012) found organic selenium supplements raised glutathione peroxidase activity in healthy adults. [4] The enzyme activity is a biomarker, not a health outcome. | Mixed (biomarker only) |
| Whey protein | A 2025 meta-analysis found no significant effect on inflammation or oxidative stress markers, including glutathione. [1] | No good evidence of benefit |
| Glutathione itself, swallowed | A 6-month placebo-controlled trial of 250 or 1,000 mg a day in 54 non-smoking adults is covered on Glutathione Supplements: Oral, Liposomal and What Evidence Supports. [5] | See that page |
Sulforaphane and broccoli
The tested form in the nasal trial was a broccoli sprout preparation, not a supplement sold in shops, and the strongest effect was at the highest amount tested, 200 g of sprouts prepared as a homogenate. [2] Study amounts are not advice. For broccoli and other cruciferous vegetables as foods, see Broccoli & Cruciferous Vegetables. We did not find a source we could read on sulforaphane supplements in pregnancy or children, or their interactions with medicines: Proper evidence not found.Selenium
The NHS says selenium helps prevent damage to cells and tissues. [6] Too much causes selenosis, which in its mildest form can lead to loss of hair and nails. [6]| Source and year | Population | Figure |
|---|---|---|
| NHS (UK), page last reviewed 2020 | Men aged 19 to 64 | 75 micrograms (mcg) a day, the amount the NHS says is needed [6] |
| NHS (UK), page last reviewed 2020 | Women aged 19 to 64 | 60 mcg a day [6] |
| NHS (UK), citing Department of Health and Social Care advice, 2020 | Adults, from supplements | 350 mcg or less a day is unlikely to cause harm [6] |
The NHS page was last reviewed in August 2020. A US figure from NIH could not be read (the site blocked us), so none is given here. The chemical form of selenium is not stated in these NHS figures. More is not better, and selenium products vary. See Selenium: Roles, Food Sources, Evidence and Toxicity and Selenium, Zinc, Copper and Manganese.
Whey
The idea behind the whey claim is that protein supplies amino acids the body can use to build glutathione. The 2025 meta-analysis found no significant change in oxidative stress markers. [1] See Whey Protein and, for the building blocks, NAC, Cysteine, Glycine and Other Glutathione Precursors.Frequently asked questions
Do foods or supplements boost glutathione?
In the trials we read, results were marker changes that varied by product. Whey showed no significant effect in a 2025 meta-analysis. [1][2]
Does broccoli raise glutathione?
A trial of broccoli sprouts raised antioxidant enzyme gene activity in nasal cells. It did not measure blood glutathione. [2]
Does selenium raise glutathione?
Selenium raised the activity of a glutathione-using enzyme in a meta-analysis of trials, which is a marker, not a health outcome. [4]
How much selenium is too much?
The NHS says 350 mcg or less a day from supplements is unlikely to cause harm and that too much causes selenosis. [6]
Is whey protein a glutathione booster?
A 2025 meta-analysis found no significant effect on oxidative stress markers. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: promising but limited, mixed, insufficient evidence, no good evidence of benefit, marketing claim. A marker change is not a clinical outcome.
Safety and who should ask a clinician first
References
- Farahmandpour F, Haidari F, Heidari Z, et al. Whey Protein Intervention and Inflammatory Factors and Oxidative Stress: Systematic Review and Meta-analysis of Randomized Controlled Trials. Nutr Rev, 2025 (PubMed abstract). Read 2026-10-23.
- Riedl MA, Saxon A, Diaz-Sanchez D. Oral sulforaphane increases Phase II antioxidant enzymes in the human upper airway. Clin Immunol, 2009 (PubMed abstract). Read 2026-10-23.
- Kikuchi M, Ushida Y, Shiozawa H, et al. Sulforaphane-rich broccoli sprout extract improves hepatic abnormalities in male subjects. World J Gastroenterol, 2015 (PubMed abstract). Read 2026-10-23.
- Jiang X, Dong J, Wang B, et al. Effects of organic selenium supplement on glutathione peroxidase activities: a meta-analysis of randomized controlled trials. Wei Sheng Yan Jiu, 2012 (PubMed abstract, article in Chinese). Read 2026-10-23.
- 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 (PubMed abstract). Read 2026-10-23.
- NHS. Other vitamins and minerals: selenium. Page last reviewed 3 August 2020 (next review listed as 3 August 2023). Read 2026-10-23.