Ergothioneine

The verdict

Is Ergothioneine worth taking?

Ergothioneine may be the most underappreciated longevity compound in this entire guide. A September 2025 review in the Proceedings of the Nutrition Society concluded it meets the criteria for classification as a longevity vitamin, a compound the body specifically accumulates and uses to protect against age-related decline. The dedicated OCTN1 transporter that the body uses to absorb and concentrate ergothioneine across multiple tissues is a strong signal that this is not just another antioxidant but one the body specifically values. Low blood ergothioneine is consistently associated with cognitive impairment, cardiovascular disease, frailty, and mortality across observational data. A 2025 randomized placebo-controlled trial confirmed cognitive function, memory, and sleep improvements in older adults. The primary food source is mushrooms.

What it does

What Ergothioneine does in the body

Neuroprotection, cognitive function support, longevity promotion through mitochondrial function enhancement and oxidative stress mitigation, anti-inflammatory activity, and cardiovascular protection. Ergothioneine is a unique sulfur-containing amino acid produced exclusively by certain fungi and soil bacteria and obtained by humans entirely through diet. It accumulates in tissues with the highest oxidative stress burden through the OCTN1 transporter, and its specific accumulation pattern strongly suggests a physiological protective role that the body prioritizes maintaining.

The evidence

What the research actually shows

Emerging with a compelling observational and mechanistic evidence base. A September 2025 review in the Proceedings of the Nutrition Society synthesized observational, interventional, and mechanistic evidence concluding ergothioneine has the hallmarks of a longevity vitamin. Observational data consistently associates low blood ergothioneine with cognitive impairment, cardiovascular disease, frailty, and increased mortality. A 2025 randomized placebo-controlled trial in older adults with subjective memory complaints found ergothioneine supplementation improved cognitive function, memory, and sleep quality with no safety concerns at doses up to 25 mg daily. A 2024 Cell Metabolism study identified ergothioneine accumulation in muscle mitochondria during exercise training and its role in enhancing mitochondrial respiration through MPST enzyme activation.

Food first

Getting Ergothioneine from food

Mushrooms are by far the primary food source of ergothioneine, with porcini (dried) and oyster mushrooms among the richest sources at 2 to 5 mg per 100 g fresh weight. King oyster, shiitake, and maitake mushrooms are commonly available and provide meaningful ergothioneine. Regular mushroom consumption is the single most practical food-first approach and may explain some of the consistent health associations with mushroom-rich dietary patterns in epidemiological research.

What the guide adds

The part that is not on this page

Everything above is the assessment. What the guide adds for Ergothioneine is the protocol:

• Optimal Form
• Bioavailability
• Purity Red Flags
• Stack With / Avoid

147 entries across nine categories, every one graded against the clinical literature the same way.

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About the author

Who graded this

Daniel Edlund is a Le Cordon Bleu-trained private chef in Los Angeles, a certified personal trainer and strength coach, and an internationally licensed massage therapist. Thirty years of strength training and fifteen years cooking in private estate kitchens. He is the author of The Complete Supplement Guide, which grades 147 entries against the clinical literature, and of The EASY Way to Organic Cooking, first published in 2013.

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This page is information, not medical advice. Supplements interact with prescription medication and with each other, and the right answer depends on your own bloodwork and history. Talk to your doctor before starting anything, particularly if you are pregnant, nursing, managing a health condition, or already taking medication.

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All 147 entries, graded →