RQS Scoring Log

Glutathione

Longevity & Cellular Aging· Human RCT· Scored June 2026· View compound profile →

60 /100

Moderate Evidence

7 dimensions · 100 points total · Methodology by PeptideClear

What this score covers

Glutathione has a real human evidence base, but it is heterogeneous and bioavailability is genuinely contested. Trials that raise body stores (e.g. Richie 2015) sit alongside trials that found no change in healthy adults. The score reflects that mixed but substantive human literature, not a settled verdict that oral or supplemental glutathione reliably delivers clinical benefit.

Dimension Breakdown

Dimension	Scoring Notes	Score
Study Design	Several human RCTs exist (oral, liposomal, and IV routes), including a 6-month placebo-controlled trial of oral GSH in 54 adults (Richie 2015). Most are biomarker / body-store endpoints rather than hard clinical outcomes, and at least one well-run trial found no change in healthy adults. Solid design, but not pharmaceutical Phase III caliber.	16 / 25
Sample Size	Individual trials run from a few dozen to a few hundred participants. Cumulative human enrollment across the GSH supplementation literature is moderate, supported by a large mechanistic and epidemiological redox-biology base.	11 / 20
Replication	Antioxidant and redox effects are heavily replicated. Whether oral supplementation meaningfully raises tissue stores is replicated inconsistently, with conflicting trials attributable to dose, duration, and assay differences.	12 / 20
Journal Impact Factor	Published across nutrition, free-radical biology, and hepatology journals (e.g. European Journal of Nutrition, European Journal of Clinical Nutrition). Mid-tier specialty journals, some well-regarded.	9 / 15
Funding Independence	Glutathione biology is overwhelmingly academic and government-funded (NIH, university redox-biology labs). Several supplementation trials are funded by ingredient suppliers (e.g. Setria), which tempers but does not dominate independence.	7 / 10
Population Diversity	Studied across varied ages and conditions, including healthy adults, elderly, and diabetic cohorts. Reasonable spread, short of broad pharmaceutical diversity standards.	3 / 5
Researcher h-Index	Foundational redox biologists carry high citation profiles, but much of the applied supplementation-trial literature is led by smaller, less-cited groups.	2 / 5

Sources: PubMed — Richie et al. 2015, Eur J Nutr (PMID 24791752). Additional human supplementation trials (Allen & Bradley 2011; Kalamkar et al. 2022) report mixed bioavailability and outcome results. Key journals: European Journal of Nutrition, European Journal of Clinical Nutrition. Funding: predominantly academic / NIH, with some ingredient-supplier-sponsored trials.

Note: Glutathione is the body's most abundant endogenous antioxidant and a genuine tripeptide (γ-glutamyl-cysteinyl-glycine). The central open question in the human literature is not whether glutathione matters biologically (it clearly does) but whether supplemental glutathione is absorbed and raises functional tissue stores. That question remains actively debated, which is why this sits at the lower edge of the Moderate band rather than higher.

Scored by the PeptideClear editorial team using publicly available literature. Sources: PubMed (study design, sample size, replication) · ScimagoJR (journal impact factor) · Google Scholar (researcher h-Index) · Primary papers (funding disclosure). Scores are reviewed as new research is published.