PMID-24791752 – Oral Glutathione Supplementation RCT Body Stores
Richie JP Jr, Nichenametla S, Neiber W, et al. "Randomized controlled trial of oral glutathione supplementation on body stores of glutathione," Eur J Nutr, 2015;54(2):251-263.
Quick Reference
| Property | Value |
|---|---|
| PMID | 24791752 |
| DOI | 10.1007/s00394-014-0706-z |
| Year | 2015 |
| Journal | European Journal of Nutrition |
| Study Type | Randomized Controlled Trial |
| Evidence Level | II |
| Sample | n=54 healthy non-smoking adults |
| Peptide(s) Studied | Glutathione |
Key Findings
- Oral glutathione supplementation (250 mg or 1000 mg/day for 6 months) significantly increased glutathione levels in blood, erythrocytes, plasma, lymphocytes, and buccal cells
- At 6 months, 1000 mg group: erythrocyte GSH increased 30-35%, plasma GSH increased 260%, lymphocyte GSH increased 186%
- After a 1-month washout, GSH levels returned toward baseline, confirming the supplementation was responsible for the increase
- Natural killer cell cytotoxicity increased over 2-fold in the 1000 mg group, suggesting immune enhancement
- No significant adverse effects at either dose level
- This was the first RCT to demonstrate that oral glutathione supplementation effectively increases body glutathione stores
Study Design
Double-blind, randomized, placebo-controlled trial. 54 healthy non-smoking adults randomized to oral glutathione 250 mg/day, 1000 mg/day, or placebo for 6 months, followed by 1-month washout. GSH levels measured in whole blood, erythrocytes, plasma, lymphocytes, and buccal cells at baseline, 1, 3, and 6 months, and after washout.
Limitations
- Small sample size (n=54)
- Healthy adults only — may not translate to disease states with oxidative stress
- No assessment of intracellular GSH in liver or other key organs
- Oral bioavailability of intact glutathione remains debated (GI degradation to amino acids)
- No assessment of functional oxidative stress endpoints beyond NK cell activity
Clinical Relevance
This RCT was pivotal in overcoming the previous consensus that oral glutathione was poorly absorbed and ineffective. The significant increases across multiple body compartments, combined with immune enhancement (NK cell activity), provide evidence supporting oral GSH supplementation. For functional medicine practitioners, this validates using oral glutathione as a practical alternative to IV administration. The dose-response between 250 mg and 1000 mg supports higher-dose supplementation for greater effect.
Related
#research #RCT #evidence-level-II #glutathione #anti-aging #immune