Lion's Mane

Full profile

Evidence, honestly graded

Held at Emerging on 2026-09-17 after a second, deeper review that went looking for every human trial rather than the headline ones. More human trials exist than this profile used to cite, but the trials reporting a benefit each use a different preparation, dose and outcome measure, so none of them replicates another. On the positive side: an early trial in mild cognitive impairment (Mori 2009); a 31-person Japanese trial of fruiting body over 12 weeks (Saitsu 2019); an acute crossover of 1 g run by a contract research organisation that improved reaction-time measures (La Monica 2023); and a 33-person pilot of an erinacine-A-enriched extract (Černelič Bizjak 2024) in which cognition was a secondary outcome and the gain reached significance only in a model adjusting for baseline score, age, sex and a biomarker. Against them: a 2023 pilot in 41 young adults (Docherty) found faster Stroop performance an hour after a dose, with mostly null results over 28 days; a 2025 crossover in 18 healthy young adults found no effect of a single 3 g extract dose on global cognition or mood; and 10 g/day for four weeks in 24 college-age adults changed nothing (Grozier 2022). The strongest new result is still a 2026 preprint, which had not been peer-reviewed when we re-checked on 2026-09-17, funded by an ingredient supplier that employs two of its lead authors: 2 g/day for 8 weeks improved one visual attention and working-memory task in adults aged 40–75, but not the memory tasks or the composite score, and more than a quarter of randomized participants were not analysed. Three further trials have completed without posting results, one of them university-led. Studied amounts are far above typical capsule doses. Peer-reviewed publication plus an independent replication with a defined extract would support a C.

See the full grading rubric (study type, replication, population match, and dose adequacy) in The Evidence Standard.

Side effects

• Generally well tolerated
• Possible skin or respiratory sensitivity in mushroom-sensitive people

The full side-effect breakdown: Lion's Mane Side Effects: What Research Reports So Far.

Who should avoid it or check first

• Known mushroom allergy
• Pregnant or breastfeeding without clinician guidance

Interactions

• Limited interaction data; discuss with a clinician if on medication

Stacks well with

• Citicoline
• Bacopa Monnieri

What to look for on a label

• Prefer fruiting-body extracts with a stated beta-glucan percentage.
• Be cautious with products that only list total polysaccharides: grain-grown mycelium can report high polysaccharide figures that are largely starch, so ask for a beta-glucan assay.

References

• Lion's Mane human pilot studies. Small and preliminary: the Mori 2009 mild-cognitive-impairment RCT (PMID 18844328) and a healthy-young-adult pilot (Docherty 2023, PMID 38004235); used for education, not claims.
• Surendran G, Saye J, Binti Mohd Jalil S, et al. (2025). Frontiers in Nutrition, 12:1405796Randomized, double-blind, placebo-controlled crossover, n=18 healthy adults aged 18–35, single doseStudied dose: 3 g of a 10:1 fruiting-body extract (single dose)No significant effect on composite global cognition or mood; one fine-motor (pegboard) measure improved at 90 minutes.
• Lion's mane RCT preprint (medRxiv, 2026). Still a preprint when we re-checked on 2026-09-17, with no journal publication and no revised version. Funded by M2 Ingredients, which employs two of the lead authors; registered as NCT06870136. 150 adults aged 40–75 with self-reported cognitive difficulty were randomized to 2 g/day of fruiting body plus mycelium or placebo for 8 weeks, and 109 were analysed. The primary visual attention/working-memory task improved; the memory tasks and composite score did not. doi:10.64898/2026.04.13.26350781.
• Černelič Bizjak M, Jenko Pražnikar Z, Kenig S, et al. (2024). Journal of Functional Foods, 115:106120Randomized, double-blind, placebo-controlled pilot, 33 analysed of 40 enrolled, healthy adults aged 55–75, 8 weeksStudied dose: Erinacine-A-enriched H. erinaceus supplement, 6 capsules/dayFaster performance on two non-verbal speed tests, significant only after adjusting for baseline score, age, sex and CHI3L1 level.
• Saitsu 2019, Biomedical Research: 12-week fruiting-body trial. 31 participants took a fruiting-body supplement for 12 weeks; the authors report improved scores on the MMSE and two memory tests. Small, and the report gives little detail on randomization or effect sizes. PMID 31413233; doi:10.2220/biomedres.40.125. Educational, not a product claim.
• La Monica 2023, Nutrients: acute 1 g crossover. A single 1 g dose of a Nordic-grown fruiting-body extract improved N-back and Go/No-go reaction time and Serial 7s attempts over two hours in a crossover trial run by a contract research organisation. A different preparation and dose from every other trial here, so it stands alone rather than replicating one. PMID 38140277; doi:10.3390/nu15245018.
• Grozier 2022, International Journal of Exercise Science: null at 10 g/day. 24 college-age adults took 10 g/day of H. erinaceus in muffins for four weeks in a single-blind design; no effect on any cognitive or metabolic measure. PMID 36582308; doi:10.70252/XZKO8571.
• Menon 2025, Frontiers in Nutrition: systematic review. Reviews five RCTs and three pilot trials, searching only to June 2024. Its discussion reaches well past that evidence base, which is a reason to read the underlying trials rather than the summary. PMID 40959699; doi:10.3389/fnut.2025.1641246.
• Completed lion's mane trials without posted results (checked 2026-09-17). ClinicalTrials.gov NCT07405632 (SWPS University, Warsaw, with the product's manufacturer as a collaborator; 85 adults aged 30–50; completed October 2025), NCT07405957 (Applied Food Sciences; 87 adults aged 40–65; two extracts against maltodextrin; completed June 2025) and NCT07665840 (University of Nottingham Malaysia; 67 students; L-theanine plus H. erinaceus gummies against a no-treatment control; completed April 2026). Unreported is not the same as negative; these are the results most likely to move this grade.

Entries above without a linked identifier are either editorial summaries of a wider body of literature or references to a named authority (a regulator or government monograph) cited by name rather than by a single paper.

Grades and studied doses are our conservative reading of the human research, shown for education. They are not product claims, and a studied dose is not a recommended dose.

Revision history

Every change to this ingredient's evidence status, dated and explained. The full cross-library log lives at Evidence Updates.

• 2026-09-17Citation review

  Deepened the lion's mane review to every human trial we could find, rather than the three this profile cited. Four more are now cited: a 31-person 12-week fruiting-body trial (Saitsu 2019), an acute 1 g crossover run by a contract research organisation (La Monica 2023), a null trial at 10 g/day for four weeks (Grozier 2022), and a 33-person pilot of an erinacine-A-standardized extract (Černelič Bizjak 2024) in which cognition was a secondary outcome and the gain held only after adjusting for baseline score, age, sex and a biomarker. The 2026 supplier-funded trial was still an unreviewed preprint when we re-checked, and three further trials have completed without posting results. The trials that report a benefit each use a different preparation, dose and outcome measure, so none replicates another. Emerging holds.

• 2026-09-14Citation review

  Reviewed for an upgrade and held at Emerging. A 2025 acute trial found no overall effect, and the strongest new result is an unreviewed, sponsor-funded 2026 preprint in which one of several cognitive tasks improved.

• 2026-07-04New profile

  Initial profile published at Grade Emerging: some small human pilot trials plus considerable preclinical work, short of the consistent healthy-adult replication a higher grade needs.

See how Lion's Mane compares on grade, dose, and goal in the Evidence Explorer.