Ingredient Evidence Review
Ergothioneine
L-ergothioneine
Last updated 2026-05-19 · 3 primary citations
Mechanism
Ergothioneine is an antioxidant that's unusual in two ways: humans can't make it (so we have to eat it), and we have a dedicated transporter that pulls it into tissues — especially the brain. It accumulates in mitochondria (the cell's power plants) where it's particularly useful. Falling blood levels are an early warning sign of cognitive decline.
Why we use it
If Lion's Mane is the first mushroom in the formula, ergothioneine is the second — quietly. It's a unique antioxidant your body actively goes out of its way to import. Perimenopausal oxidative stress drains it; this restores supply at the dose shown to improve cognition in early trials.
How we dose it
Hericea uses 25 mg per serving (per PM packet). The clinical trial range that anchors this dose is 10–25 mg/day.
25 mg — the dose that hit the cognition endpoint in the most recent ergothioneine clinical trial. Naturally found in mushrooms; most modern diets supply less than your tissues want.
Quality & sourcing
MitoPrime® standardized; Blue California fermentation-derived; FDA GRAS GRN 734.
Fermentation-derived ergothioneine; Blue California-licensed.
Primary literature
Yau YF et al. (2024)
J Alzheimers DisPilot RCT in MCI
Ergothioneine 25 mg/day improved learning ability and stabilized a blood marker of brain-cell damage (neurofilament light chain) vs placebo.
Direct human evidence at our exact dose. The cohort — mild cognitive impairment — overlaps with the brain-fog perimenopausal customer.
PMID 39544014
Wu LY, Cheah IK et al. (2022)
Antioxidants (Basel)Cohort study
Lower blood ergothioneine levels predicted faster cognitive and functional decline in elderly adults attending memory clinics.
Establishes ergothioneine status as a real, measurable variable that tracks brain aging — the case for keeping it topped up.
PMID 36139790
Halliwell B et al. (2025)
Free Radic Biol MedComprehensive review
Reviewed the entire ergothioneine evidence base — argues it deserves status as a 'longevity vitamin' the body actively conserves.
From the same lab that has driven the research. Useful single source for the full mechanism and clinical picture.
PMID 40968729