What does the evidence show about Ergothioneine's effects?

Read Off Label rates the evidence for Ergothioneine as Weak-Moderate and the benefit magnitude as variable, producing an overall grade of B (6.4/10). Cheah/Halliwell and Ames advocacy as possibly essential nutrient.

What safety findings are reported for Ergothioneine?

Ergothioneine has a low risk profile in the database. Low Legal status: OTC.

What doses or routes are reported for Ergothioneine?

5-10 mg/day; mushrooms are the main dietary source (oyster, king trumpet) This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.

Rankings / Mitochondria & Cellular Energy

Ergothioneine

Mitochondria & Cellular Energy · Fungal amino acid

Tier B

Reviewed by Read Off Label · Last reviewed Jul 1, 2026 · How we grade

mitochondrialvitaminantioxidantotc

6.4 / 10

Tier B

Ev 4.5 Bn 5 Sf 9

Bottom line

Read Off Label grades Ergothioneine as B (6.4/10) based on weak-moderate evidence, variable benefit magnitude, and a low-risk safety profile.

Cheah/Halliwell and Ames advocacy as possibly essential nutrient.

Studied, labeled, or reported-use context: 5-10 mg/day; mushrooms are the main dietary source (oyster, king trumpet) — OTC; not individualized guidance.

What the evidence says

Cheah/Halliwell and Ames advocacy as possibly essential nutrient. Decline with age correlates with cognitive dysfunction in several cohorts. Accumulates in tissues under oxidative stress. No completed longevity RCTs; the evidence base is mechanistic and observational.

Mechanism

Unique sulfur-containing amino acid; accumulates in specific tissues via OCTN1 transporter; powerful antioxidant in mitochondria; proposed 'longevity vitamin' (Ames)

Studied, labeled, or reported dose & route

5-10 mg/day; mushrooms are the main dietary source (oyster, king trumpet)

This records doses and routes described in studies, approved labeling, clinical practice, or documented use. It is not individualized guidance and does not establish safety; context changes with indication, formulation, health history, monitoring, and other medicines.

Citations

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Common questions

What does the evidence show about Ergothioneine's effects?: Read Off Label rates the evidence for Ergothioneine as Weak-Moderate and the benefit magnitude as variable, producing an overall grade of B (6.4/10). Cheah/Halliwell and Ames advocacy as possibly essential nutrient.
What safety findings are reported for Ergothioneine?: Ergothioneine has a low risk profile in the database. Low Legal status: OTC.
What doses or routes are reported for Ergothioneine?: 5-10 mg/day; mushrooms are the main dietary source (oyster, king trumpet) This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.
How does Ergothioneine work?: Unique sulfur-containing amino acid; accumulates in specific tissues via OCTN1 transporter; powerful antioxidant in mitochondria; proposed 'longevity vitamin' (Ames)

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.