Cheah I.K., Tang R.M.Y., Yew T.S.Z., Lim K.H.C., Halliwell B. Administration of Pure Ergothioneine to Healthy Human Subjects: Uptake, Metabolism, and Effects on Biomarkers of Oxidative Damage and Inflammation. Antioxid Redox Signal. 2017;26(5):193–206.
Rationale
Ergothioneine is a mushroom-derived antioxidant that mammals cannot synthesize but absorb efficiently via the dedicated OCTN1 transporter — an unusual situation suggesting an evolved role. This work characterized how pure ergothioneine behaves in healthy humans: uptake, distribution, elimination and tolerability.
Methods
Healthy volunteers received oral ergothioneine; plasma and urine levels were tracked over time along with safety panels — essentially a clinical pharmacokinetic and safety profile of the compound as a supplement ingredient.
Results
Ergothioneine was well absorbed orally, accumulated in erythrocytes and plasma, and was cleared slowly — consistent with retention by tissues expressing OCTN1. No clinically significant adverse effects were recorded.
Conclusions
Oral ergothioneine is bioavailable and well tolerated, with pharmacokinetics consistent with a long-lived cellular antioxidant. This underpins its study in age-related conditions and explains why mushroom-rich diets measurably raise blood ergothioneine.
Worth noting
A pharmacokinetics paper, not an efficacy trial — it establishes that ergothioneine gets where it is supposed to go, not that it does something useful there. The existence of a dedicated transporter remains the strongest argument that ergothioneine is not merely a marker of mushroom intake but a functional molecule; clinical-outcome data are still being gathered.