Lion's Mane

• 30 subjectsrandomized · 16 weeks
• weeks 8, 12 and 16HDS-R significant vs placebo
• 250 mg x4 x3/dayYamabushitake dry powder

In the flagship human trial, older Japanese adults (50-80 y) with mild cognitive impairment taking Lion's Mane powder scored significantly higher on a Revised Hasegawa Dementia Scale (HDS-R)-based cognitive scale than placebo at weeks 8, 12 and 16, with no adverse effects on lab tests. The improvement scaled with duration of intake. This is a small, single-center research finding, not evidence that Lion's Mane treats or prevents dementia.

Reported effect: n=30 (two 15-person groups); 4x250 mg tablets (96% dry powder) three times daily for 16 weeks; Yamabushitake group showed significantly increased cognitive-scale scores vs placebo at weeks 8, 12 and 16

“After 2 weeks of preliminary examination, 30 subjects were randomized into two 15-person groups... The subjects of the Yamabushitake group took four 250 mg tablets containing 96% of Yamabushitake dry powder three times a day for 16 weeks... At weeks 8, 12 and 16 of the trial, the Yamabushitake group showed significantly increased scores on the cognitive function scale compared with the placebo group.”

Source: PMID 18844328 · Mori 2009 · Phytother Res

• 41healthy adults 18-45
• p = 0.005faster Stroop at 60 min
• p = 0.051stress trend at 28 days

A double-blind parallel-groups pilot in healthy young adults found faster Stroop-task performance 60 minutes after a 1.8g dose (p=0.005), and a trend toward reduced subjective stress after 28 days (p=0.051, not statistically significant). The authors explicitly frame this as a small pilot warranting cautious interpretation and larger trials.

Reported effect: n=41 (ages 18-45); 1.8g Lion's Mane; faster Stroop performance at 60 min (p=0.005); reduced subjective stress trend after 28 days (p=0.051)

“Acute cognitive effect: Faster performance on the Stroop task at 60 minutes (p = 0.005); Chronic effect: Trend toward reduced subjective stress after 28 days (p = 0.051)”

Source: PMID 38004235 · Docherty 2023 · Nutrients

• 30 femalesrandomized · 4 weeks
• 2 ICI subscaleslower vs placebo

In a 4-week RCT of 30 women, depression (CES-D) and Indefinite Complaints Index (ICI) scores were significantly lower after Lion's Mane intake than at baseline, and two ICI subscales were significantly lower than placebo. The authors note this suggests a mechanism different from NGF enhancement and frame it as a possibility, not an established antidepressant effect.

Reported effect: n=30 females, 4 weeks; CES-D and ICI scores significantly lower after HE intake vs before; two ICI subscales ('insentive','palpitatio') significantly lower in HE group vs placebo

“Each of the CES-D and the ICI score after the HE intake was significantly lower than that before. In two terms of the ICI, "insentive" and "palpitatio", each of the mean score of the HE group was significantly lower than the placebo group.”

Source: PMID 20834180 · Nagano 2010 · Biomed Res

• 49 weekstreatment period
• 3 x 350 mg/dayEAHE mycelia

A double-blind pilot of erinacine A-enriched mycelia (EAHE) over 49 weeks reported significantly improved Mini-Mental State Examination scores in the EAHE group while the placebo group declined on a separate cognitive screening instrument, plus a between-group difference in Instrumental Activities of Daily Living. Four participants dropped out for GI/skin issues. This is a small pilot, not proof Lion's Mane treats Alzheimer's disease.

Reported effect: Three 350 mg EAHE mycelia capsules daily (5 mg/g erinacine A) for 49 weeks; EAHE group significant MMSE improvement; placebo group significant decrease in Cognitive Abilities Screening Instrument; significant between-group IADL difference

“EAHE group showed 'significant improvement in Mini-Mental State Examination score'; Placebo group demonstrated 'significant decrease in Cognitive Abilities Screening Instrument score'; Significant difference in Instrumental Activities of Daily Living scores between groups”

Source: PMID 32581767 · Li 2020 · Front Aging Neurosci

• 12 weeksfruiting-body intake

In a 12-week double-blind RCT using three cognitive tests (MMSE, Benton visual retention, S-PA paired-associate learning), only the MMSE showed a significant improvement and protection from deterioration; the other two tests did not. The honest read is selective benefit on one global screen rather than broad cognitive enhancement.

Reported effect: 12-week randomized double-blind trial; of MMSE, Benton visual retention test and S-PA, MMSE alone significantly improved cognitive function (no quantitative effect size in abstract)

“We performed three kinds of tests: Mini Mental State Examination (MMSE), Benton visual retention test, and Standard verbal paired-associate learning test (S-PA). MMSE alone showed that oral intake of H. erinaceus significantly improved cognitive functions and prevented from the deterioration.”

Source: PMID 31413233 · Saitsu 2019 · Biomed Res

A 2025 systematic review of the clinical literature concluded Lion's Mane shows promising neuroprotective, cognitive, gut-health and mood-related signals, while flagging commonly underreported side effects (stomach discomfort, headache, allergic reactions). It is a qualitative synthesis establishing a safety profile, not a pooled meta-analysis with a quantified effect size.

Effect size: this study reports the direction of the finding but does not state a specific numeric effect size, so none is given here rather than estimated.

“HE is effective in neuroprotection, enhancing cognitive function, preventing and alleviating cancer, promoting gut health, and improving symptoms of anxiety and depression. Although commonly unreported, potential side effects of HE include stomach discomfort, headache, and allergic reactions.”

Source: PMID 40959699 · Menon 2025 · Front Nutr