Lion's Mane Mushroom: Evidence for Brain Health and Cognitive Function

Physician Reviewed | Last reviewed: May 2026

Lion's mane is widely promoted for brain health. The human evidence is genuinely interesting but still early — and the quality of the product you buy matters more here than for almost any other supplement.

What Is Lion's Mane

Hericium erinaceus is a culinary and medicinal mushroom used in traditional East Asian medicine. It contains two unique compound classes — hericenones (from the fruiting body) and erinacines (from the mycelium) — that stimulate Nerve Growth Factor (NGF) synthesis in the brain.

Evidence — Cognitive Function

A 2009 randomized controlled trial (Mori et al., Phytotherapy Research, 30 subjects with mild cognitive impairment) found that 250mg of lion's mane (96% purity) three times daily for 16 weeks significantly improved cognitive function scores versus placebo. Notably, scores declined after participants stopped taking it — suggesting continued use is required for sustained benefit. A 2023 trial (Saitsu et al., Biomedical Research) found that 1.8g of lion's mane daily for 12 weeks improved processing speed and working memory in healthy young adults.

Evidence — Depression and Anxiety

A 2010 study (Nagano et al., Biomedical Research, 30 women) found that lion's mane taken for 4 weeks significantly reduced depression and anxiety scores compared with placebo.

Nerve Growth Factor

Multiple in vitro and animal studies confirm that hericenones and erinacines stimulate NGF. Direct measurement of NGF in the human brain is limited, so this mechanism is not fully proven in people — but the cognitive improvements seen in human trials are biologically consistent with NGF activity.

Important Caveats

Most human trials are small (30–60 subjects) and short-term. Larger randomized controlled trials are needed before definitive clinical recommendations can be made. Treat lion's mane as promising rather than proven.

Quality warning — critical for this supplement. Many lion's mane products are primarily grain substrate — the material the mushroom is grown on — rather than actual mushroom fruiting body. Grain-based mycelium products may contain very little active hericenone content. Look for "fruiting body only" clearly stated on the label, and avoid products that list "mycelium on grain" as the primary ingredient. Third-party testing and a certificate of analysis are essential in this category.

Dosing

500–3,000mg daily of fruiting-body extract. Published studies have used 250mg up to 1.8g; higher doses are generally used for cognitive effects.

Safety

Lion's mane is well-tolerated in studies. Rare allergic reactions have been reported — avoid it if you have a mushroom allergy.

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Double Wood Lion's Mane uses 1,000mg of fruiting body per serving, is grown in the USA, and is third-party tested:

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Sources

  1. Mori et al. (2009). Phytotherapy Research.
  2. Saitsu et al. (2023). Biomedical Research.
  3. Nagano et al. (2010). Biomedical Research.
This article is for educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult a licensed healthcare provider before starting any supplement, particularly if you have a medical condition or take medications. Individual results vary. Supplements are not FDA-approved to diagnose, treat, cure, or prevent any disease.