Ergothioneine
A unique sulfur-containing antioxidant the body has a dedicated transporter for — suggesting it's important. Concentrated in mushrooms; depleted with age.
Strong mechanism and tissue-distribution evidence (the dedicated transporter is striking). Observational evidence links higher ergothioneine to lower frailty, cognitive decline, and cardiovascular events. Clinical trial data is still building. Effects: 4–12 weeks for biomarker shifts.
Ergothioneine is a naturally occurring amino acid synthesised by fungi and certain bacteria — the body doesn't make it. What's unusual: humans have a dedicated cellular transporter (OCTN1) specifically for ergothioneine, which strongly suggests it has an important role. It accumulates in tissues with high oxidative stress (liver, brain, kidney, bone marrow, eye) where it acts as a powerful, slow-acting antioxidant. Levels decline with age, and low ergothioneine has been associated with mild cognitive impairment, frailty, and cardiovascular events. Bryan Earthman's lab at Johns Hopkins has called it a 'longevity vitamin' candidate. Easy to get from mushrooms; supplementation is becoming available.
- Form
- Pure ergothioneine (synthesised via fermentation — usually 5–30 mg per capsule). Mushroom extracts high in ergothioneine (especially oyster mushroom, king trumpet, shiitake).
- Dose
- 5–30 mg/day from supplements. Mushroom-derived diets typically deliver 5 mg/day at most; a deliberate mushroom-heavy diet can go higher.
- Timing
- Anytime, with or without food.
- Schedule
- Daily.
- Side effects
- Generally very well-tolerated. No notable side effects in clinical trials.
- Interactions
- Generally clean. Theoretical: chemotherapy (any potent antioxidant may interact — discuss with oncology).
- Contraindications
- None known at supplement doses.
- Lab markers
- Whole-blood ergothioneine (specialty labs offer this — useful for tracking baseline and response).
- Food sources
- Mushrooms — oyster, king trumpet, shiitake, maitake, lion's mane (highest concentrations); button and portobello have less but still significant. Black turtle beans, chicken liver, and oat bran have small amounts. Cooking does NOT destroy ergothioneine (unlike many other compounds — it's heat-stable).
Pairs with
Glutathione, NAC (antioxidant network — ergothioneine specifically protects against peroxynitrite which other antioxidants don't handle well). Other mushroom extracts (lion's mane, reishi — beta-glucan synergy).
within Polyphenols & antioxidants