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Lion's mane mushroom and reaction time: grade C

Limited evidence. Direction: No effect.

C LimitedIndustry-fundedShort-term only

Educational guidance, not medical advice

Why this grade

Rubric condition met: C: small single-dose and 4-week trials in healthy adults with inconsistent results (evidence is mixed)

Evidence is mixed. Single doses were followed by faster Stroop performance (acute analysis n=43) and faster reaction time on two tasks (n=40, part-funded by the extract supplier), but a third single-dose crossover (n=18, two authors employed by a company selling lion's mane products) found no effect on composite cognition. A 4-week trial of 10 g a day (n=24) and an uncontrolled 4-week pilot (n=10) found no significant change.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)202020252030RCTCrossover RCTPilot single-arm…Single-blind, pla…Docherty 2023, 2023: RCT, n = 41, result not recordedLa 2023, 2023: crossover RCT, n = 40, result not recordedGrozier 2022, 2022: single-blind, placebo-controlled parallel trial (4 weeks), n = 24, result not recordedSurendran 2025, 2025: crossover RCT, n = 18, result not recordedEvans 2026, 2026: pilot single-arm pre-post study, no placebo group (4 weeks), n = 10, result not recorded
each study this grade rests on, by publication year and design. Solid: effect versus the comparator; half-filled: mixed; hollow: no effect; dashed: result not recorded yet. Larger marks had more participants.
Show the numbers
StudyYearDesignParticipantsResult
Grozier 20222022single-blind, placebo-controlled parallel trial (4 weeks)24result not recorded
La 20232023crossover RCT40result not recorded
Docherty 20232023RCT41result not recorded
Surendran 20252025crossover RCT18result not recorded
Evans 20262026pilot single-arm pre-post study, no placebo group (4 weeks)10result not recorded

A Pilot Proof-of-Concept Study to Evaluate the Physiological and Cognitive Impacts of Hericium erinaceus on Healthy Adults.

Evans C, Kalman D, Goodrich J. A Pilot Proof-of-Concept Study to Evaluate the Physiological and Cognitive Impacts of Hericium erinaceus on Healthy Adults Nutrients, 2026. PMID 42884628

Result not recorded
Design
Pilot single-arm pre-post study, no placebo group (4 weeks)
Sample
n = 10
Population
Healthy adults aged 18-55
Funding
Unrestricted educational grant from the International Society of Sports Nutrition; test product supplied by M2 Ingredients

Four Weeks of Hericium erinaceus Supplementation Does Not Impact Markers of Metabolic Flexibility or Cognition.

Grozier CD, Alves VA, Killen LG. Four Weeks of Hericium erinaceus Supplementation Does Not Impact Markers of Metabolic Flexibility or Cognition Int J Exerc Sci, 2022. PMID 36582308

Result not recorded
Design
Single-blind, placebo-controlled parallel trial (4 weeks)
Sample
n = 24
Population
College-age adults
Funding
not stated

Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance.

La Monica MB, Raub B, Ziegenfuss EJ. Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance Nutrients, 2023. PMID 38140277

Result not recorded
Design
Randomized, double-blind, placebo-controlled three-arm crossover trial (single doses)
Sample
n = 40
Population
Healthy men and women aged 18-50 who habitually consumed up to 240 mg caffeine a day
Funding
Funded in part by Applied Food Sciences Inc. (ingredient supplier)

Acute effects of a standardised extract of Hericium erinaceus (Lion's Mane mushroom) on cognition and mood in healthy younger adults: a double-blind randomised placebo-controlled study.

Surendran G, Saye J, Binti Mohd Jalil S. Acute effects of a standardised extract of Hericium erinaceus (Lion's Mane mushroom) on cognition and mood in healthy younger adults: a double-blind randomised placebo-controlled study Front Nutr, 2025. PMID 40276537

Result not recorded
Design
Randomized, double-blind, placebo-controlled crossover trial (single dose)
Sample
n = 18
Population
Healthy adults aged 18-35
Funding
Beyond Alcohol Ltd. (Three Spirit Drinks) contributed towards the publication fee

The Acute and Chronic Effects of Lion's Mane Mushroom Supplementation on Cognitive Function, Stress and Mood in Young Adults: A Double-Blind, Parallel Groups, Pilot Study.

Docherty S, Doughty FL, Smith EF. The Acute and Chronic Effects of Lion's Mane Mushroom Supplementation on Cognitive Function, Stress and Mood in Young Adults: A Double-Blind, Parallel Groups, Pilot Study Nutrients, 2023. PMID 38004235

Result not recorded
Design
Randomized, double-blind, placebo-controlled parallel-group pilot trial (acute and 28-day)
Sample
n = 41
Population
Healthy adults aged 18-45
Funding
No external funding; investigational product provided by Sempera Organics (manufacturer), which had no role in design, analysis or writing

Search and history

Search (): (Hericium erinaceus[tiab] OR "lion's mane"[tiab]) AND 2024:2026[dp] AND (randomized[tiab] OR placebo[tiab])

  • Graded C (proposed): Proposed in the monograph draft
  • C to C (proposed): Editor review ed-2026-11-11: C kept, direction changed from benefit to none: positives were isolated tasks in single-dose trials and the page concludes no consistent effect; industry-funded added because 4 of 5 studies had a supplier funder, employer or product donor (policy 3.3).
  • C to C (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page