Pump
L-Glutathione
L-Glutathione is an antioxidant with no evidence that a small single pre-workout dose improves performance.
How it counts: Not part of the score
We show it on the label and count it as disclosed, but it never affects Dose, any sub-score or the grade. The basis below explains why.
- Clinical dose
- No established clinical dose
- Safety ceiling
- —
- Evidence
- weak
- Category
- Pump
Evidence summary
Research confidence: low
No reference dose. Glutathione is the body's main internal antioxidant. Taken by mouth for months, 250-1000 mg a day raised body stores in one trial, while 1000 mg a day for 4 weeks changed nothing in another. The exercise studies pair 200 mg with 2 g of citrulline, which raised nitric-oxide markers but not strength, or use 1000 mg a day for 2 weeks in 8 people; none shows a single 100 mg pre-workout dose doing anything measurable.
Research sources
- Randomized controlled trial of oral glutathione supplementation on body stores of glutathione (Richie et al., Eur J Nutr 2015)(opens in new window)
- Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers (Allen & Bradley, J Altern Complement Med 2011)(opens in new window)
40 adults, 500 mg twice daily for 4 weeks: no change in oxidative-stress markers or blood glutathione.
- Combined L-citrulline and glutathione supplementation increases the concentration of markers indicative of nitric oxide synthesis (McKinley-Barnard et al., JISSN 2015)(opens in new window)
Resistance-trained men, 7 days: 200 mg Setria + 2 g L-citrulline raised plasma nitrite/NOx 30 min after arm exercise vs placebo; no performance outcome. Setria supplied by Kyowa Hakko Bio; one author a Kyowa employee.
- Eight weeks of resistance training in conjunction with glutathione and L-Citrulline supplementation increases lean mass and has no adverse effects on blood clinical safety markers in resistance-trained males (Hwang et al., JISSN 2018)(opens in new window)
75 trained men: 200 mg Setria + 2 g citrulline before training; lean mass higher than placebo at week 4 only, strength gains not different. Kyowa-supplied product, Kyowa-employed co-author.
- Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism (Aoi et al., JISSN 2015)(opens in new window)
8 men, 1 g/day for 2 weeks, crossover: lower blood lactate and fatigue ratings after 60 min of easy cycling. Co-authors from KOHJIN Life Sciences (a glutathione maker).