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Ergothioneine: does it work, and at what %?
Ergothioneine is one of the actives we grade on evidence, not marketing. The benefit is real — but only when the dose clears the threshold the research supports. Here's the number, and the products that actually hit it.
The verdict: Topical 0.1% ergothioneine reduced the melanin index and raised the individual typology angle in UV-irradiated skin over 4 weeks, consistent with its tyrosinase-inhibiting and Nrf2-activating antioxidant activity.
How we grade Ergothioneine
We check the disclosed concentration against the effective threshold from peer-reviewed dermatology literature and regulatory monographs, then weigh the formulation and any product-specific study. The grade is computed from the open rubric — re-run it on any ingredient list and you get the same letter. Also labeled as L-Ergothioneine, EGT.
Products with a disclosed effective dose
We haven't yet graded a product that discloses an effective dose of Ergothioneine — most brands won't publish the concentration. As brands disclose (or get Verified), graded products will appear here. Browse the full index →
Common questions
What concentration of Ergothioneine is effective?
On Visage Theory's rubric, Ergothioneine reaches an effective dose at 0.1% and a strong, research-backed dose at 0.1%. Below that, the labeled benefit is unlikely no matter how good the marketing is.
Is more Ergothioneine always better?
Not necessarily — past the effective range you mostly add irritation risk, not benefit. What matters is clearing the threshold in a stable formula, which is exactly what our grade checks.
How do I know a product actually contains an effective dose of Ergothioneine?
Most brands list the active but hide the concentration. When the dose isn't disclosed we can't confirm efficacy, so we withhold a grade rather than guess. Products that disclose an effective dose are graded and listed below.
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