CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-11). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 264 · Search date 2026-07-11 · Methodology v0.6

Ergothioneine,
does it really help with Antioxidant effects and healthy aging?

30-Second Summary
C
Evidence Grade C · 40 · Safety acceptable
Absorption and selected exploratory signals are documented, but antioxidant and healthy-aging effects in humans remain unconfirmed
What the
research shows
Ergothioneine is absorbed and retained in humans and was generally well tolerated in short-term and one-year supplementation trials. However, most oxidative-damage and inflammatory biomarkers in a 45-person trial were not significant, and the primary memory endpoint in a 147-person trial of older adults did not differ from placebo. Signals in learning and a neuronal-injury biomarker from a 19-person mild-cognitive-impairment pilot were too small to establish the claim, so antioxidant effects and healthy aging are rated C.
What the
ads claim
Marketing combines a dietary antioxidant, a longevity nutrient, and protection from brain aging into one effect. Human data mainly concern blood concentrations, oxidative-damage biomarkers, short-term cognitive tests, and a neuronal-injury biomarker, not healthspan, mortality, or lifespan.
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Useful facts when choosing a product

  • Human trials used 5-25 mg/day or 25 mg three times weekly.
  • The 45-person short trial found dose-dependent increases in blood ergothioneine.
  • The primary composite-memory endpoint in the 147-person trial was not significant versus placebo.
  • No supplementation trial directly measured healthspan or lifespan extension.
Gap Measurement · Verdict 264 · C 40
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The Cheah 2017 trial assigned 45 healthy men to placebo, 5 mg, or 25 mg for seven days and confirmed blood accumulation, but most oxidative-damage and CRP changes were not significant. The Yau 2024 pilot enrolled 19 people with mild cognitive impairment, of whom 14 completed one year of 25 mg three times weekly, and reported signals in a learning test and stabilization of neurofilament light. The Zajac 2025 trial gave 10 mg or 25 mg for 16 weeks to 147 older adults with subjective memory complaints; the primary composite-memory endpoint did not differ from placebo, while selected subjective memory and sleep outcomes were positive.

02

Why this is classified as C (40)

Randomized human trials and bioavailability data mean the evidence is not ungradable, but mostly negative antioxidant biomarkers, a negative primary endpoint in 147 participants, and reliance on a small pilot and exploratory outcomes place it at the bottom of C with 40 points.

Counterpoint. Signals in learning and a neuronal-injury biomarker were observed in people with mild cognitive impairment, so this judgment does not state that every human effect is absent.

Rejudgment record. New judgment — Human RCTs exist, but most oxidative-damage biomarkers were nonsignificant, the primary memory endpoint in 147 participants was negative, and no direct healthspan endpoint exists

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Antioxidant biomarkersCA 45-person trial showed downward trends, but most changes were nonsignificant
Healthspan and lifespan extension?No trial directly assessed human healthspan, mortality, or lifespan

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Cheah IK et al. 2017Randomized double-blind placebo-controlled pharmacokinetic and biomarker trial45UnknownBlood concentrations, oxidative damage, and CRPBlood accumulation was dose-dependent, but most oxidative-damage and inflammatory biomarker changes were nonsignificant.Key
Yau YF et al. 2024Double-blind randomized placebo-controlled pilot14Singapore academic researchCognitive tests, neurofilament light, and safetyLearning-test and neurofilament-light stabilization signals were reported, but only 14 participants completed the trial.Supportive
Zajac IT et al. 2025Randomized double-blind placebo-controlled dose-ranging trial147Phyto Tech/Blue CaliforniaComposite memory, cognition, sleep, and telomere length at 16 weeksThe primary composite-memory outcome did not differ from placebo; only selected subjective and exploratory outcomes were positive.Key
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-11).

Cheah IK, Tang RMY, Yew TSZ, Lim KHC, Halliwell B. 2017. Administration of Pure Ergothioneine to Healthy Human Subjects: Uptake, Metabolism, and Effects on Biomarkers of Oxidative Damage and Inflammation. Antioxid Redox Signal. 26(5):193-206. DOI: 10.1089/ars.2016.6778.
checked
Yau YF, Cheah IK, Mahendran R, et al. 2024. Investigating the efficacy of ergothioneine to delay cognitive decline in mild cognitively impaired subjects: A pilot study. J Alzheimers Dis. 102(3):841-854. PMID: 39544014. DOI: 10.1177/13872877241291253.
checked
Zajac IT, Kakoschke N, Kuhn-Sherlock B, May-Zhang LS. 2025. The Effect of Ergothioneine Supplementation on Cognitive Function, Memory, and Sleep in Older Adults with Subjective Memory Complaints: A Randomized Placebo-Controlled Trial. Nutraceuticals. 5(3):15. DOI: 10.3390/nutraceuticals5030015.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-11 · Corrections: none

Cite this verdict

Ergothioneine x Antioxidant effects and healthy aging Evidence Grade C card
[Chamgap] Ergothioneine x Antioxidant effects and healthy aging — Evidence Grade C·40. 3 cited sources checked. Source: https://health-receipt.pages.dev/en/verdicts/antioxidant-aging/ergothioneine-antioxidant-healthy-aging/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.