Ergothioneine

Supplements · Antioxidants · Supplement, Typed Supps

An antioxidant your body can only get from food or supplements — mainly mushrooms.

Stage by stage

Intake (Capsule): Absorbed via a dedicated transporter, unusual for an antioxidant compound.
Small intestine (Dedicated transporter): A specific transporter (OCTN1) actively pulls it into the body, suggesting an important biological role.
Bloodstream (Accumulates in tissues): Circulates and concentrates in certain tissues, including the eyes, skin, and liver.
Cellular antioxidant defense (Emerging research): Studied for antioxidant protection at the cellular level, though human research is newer and less extensive than for more established antioxidants.

What the evidence supports

Improving any clinical health outcome — insufficient evidence. Higher blood levels track with lower disease risk in observational data, but there are almost no completed intervention trials showing benefit from supplementing it.
Improving skin moisture and condition — limited evidence. A small number of short randomised skin trials report modest changes. Early, small and not yet replicated broadly.
Evidence on Safety at supplement doses — moderate evidence. EFSA derived a no-adverse-effect level supporting up to 30 mg/day, and the US FDA granted GRAS status; small trials found it well tolerated.

Typical dose

5–30 mg daily

Upper limit: No established UL; EFSA considered supplemental intakes up to 30 mg/day safe for adults

Timing

With food, standard dosing.

Time to effect

Unclear: Human research is still relatively new compared to more established antioxidants.

Common myth

“Ergothioneine is a proven anti-ageing supplement in humans.” In reality: The dedicated-transporter discovery is genuinely interesting science, but long-term human outcome data is still limited.