Ergothioneine
A rare sulfur-containing amino acid from mushrooms that accumulates in cells via a dedicated transporter and acts as a cytoprotective antioxidant. Nicknamed a 'longevity vitamin,' it is backed by strong observational data linking higher blood levels to lower mortality, but interventional human outcome trials are lacking.
01 Overview
Ergothioneine is a naturally occurring thiol amino acid produced by fungi and some bacteria and concentrated in mushrooms. Humans cannot synthesise it but possess a specific transporter (OCTN1/SLC22A4) that actively takes it up and accumulates it in tissues exposed to oxidative stress, which led researchers to propose it as a candidate 'longevity vitamin.'
It is a highly stable antioxidant and cytoprotectant. The strongest human evidence is observational: in large cohorts, higher plasma ergothioneine is associated with lower risk of cardiovascular disease and all-cause mortality, and blood levels decline with age and certain diseases. Interventional trials are small and mostly focused on safety and biomarkers rather than outcomes. It is very well tolerated.
02 Mechanism
Actively transported into cells by OCTN1, where it acts as a stable antioxidant and cytoprotectant, scavenging reactive species and protecting mitochondria and DNA under oxidative stress.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 5–30 mg/day | Oral | Supplement doses typically 5-30 mg/day; higher doses studied for safety. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Higher blood levels linked to lower mortalityLarge cohorts associate higher plasma ergothioneine with reduced cardiovascular and all-cause mortality. | association only | Observational | |
| Cellular antioxidant / cytoprotectionProtects cells, mitochondria, and DNA from oxidative damage in laboratory models. | robust in vitro | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Very well toleratedNo significant adverse effects observed in safety studies at supplemental doses. | Mild | Rare | Clinical | |
| No outcome-trial evidenceBenefits are inferred from associations; no controlled trial shows it reduces disease or extends life in humans. | Mild | Inherent | Unconfirmed |