Verified research record · Human RCT
The Effect of Ergothioneine Supplementation on Cognitive Function, Memory, and Sleep in Older Adults with Subjective Memory Complaints: A Randomized Placebo-Controlled Trial
Zajac IT et al. · Nutraceuticals · 2025
- Population
- Adults aged 55–79 with subjective memory complaints but no diagnosed mild cognitive impairment
- Participants
- 147
- Intervention
- 10 mg/day, 25 mg/day, or placebo
- Duration
- 16 weeks
- Topics
- Human, Cognitive, Sleep, Safety
- DOI
- 10.3390/nutraceuticals5030015
Key finding
Supplementation increased plasma ergothioneine, but the primary composite-memory outcome did not show a significant treatment effect at 16 weeks. Selected secondary, subjective, or time-by-treatment signals were reported.
Important limitations
The primary cognitive outcome was null; an early within-group signal was not sustained; several positive findings were secondary, subjective, per-protocol, or within-group results.
Editorial interpretation
Important preliminary clinical evidence, but not confirmation that ergothioneine reliably improves memory or cognition.
Funding and conflicts
Funded by Phyto Tech Corp (Blue California). One author was employed by Blue California; other authors reported study funding.