Supplement
Lion's Mane Mushroom
Cognitive test scores in older adults with mild cognitive impairment, on one small positive trial of fruiting-body powder and one partial replication The same finding reproduced by a separate research group. A result seen once can be chance or bias; a replicated one is harder to explain away..
Grade C: human trials exist, but they are small, mixed or not yet repeated. This is not a finding that it does not work. How to read a grade →
Lion's mane is a mushroom sold for memory and brain health. In one small study of older adults with mild memory problems, people taking the mushroom powder scored better on memory tests than people taking a dummy pill. The gain faded after they stopped. A second study partly matched that result. The lead researcher of the first study worked for a mushroom company. No study measured brain nerve growth in people.
A letter describes the human evidence, not the product, the manufacturer, or the ingredient's worth.
See the full evidence record →Investigators: The single trial this Grade C rests on was run by investigators employed by, founded by, or belonging to the organization that developed, sells or teaches the intervention (the lead author's affiliation is the mushroom laboratory of a commercial mushroom producer). The funder may read non-commercial; the people who ran the trial are part of the organization whose intervention they tested, which is stated here so it can be weighed alongside the letter.
Cognitive test scores in older adults with mild cognitive impairment, on small randomized trials.
Why this gradeGrade C, small or unreplicated trials. The reasoning, and what the grade does not cover.
Grade C on measured cognitive tests in older adults with mild cognitive impairment. One small double-blind trial (Mori et al., 2009; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 18844328; 30 adults, about 3 g/day of fruiting-body powder for 16 weeks) found clinician-administered HDS-R scores higher than placebo An inactive substitute made to look like the real treatment, so participants cannot tell which one they received., falling after stopping; its lead author worked at a commercial mushroom producer's laboratory, stated beside the letter. Saitsu et al. (2019; PMID 31413233) improved one of three cognitive tests in healthy older adults, a partial result. Trials in healthy young adults were null or mostly null (PMIDs 36582308, 38004235, 40276537). A single clean positive trial with a partial second is C.
WHAT THIS GRADE DOES NOT COVERnerve growth factor, neuroplasticity, nerve repair and mood, which no cited trial measured; healthy adults, in whom benefit has not been shown; the 500 to 1,000 mg extract doses sold, which no positive chronic trial used; and erinacine-enriched mycelium (Li et al., 2020; PMID 32581767), a different form tested in mild Alzheimer's disease by its maker. Aligned with the lion's mane protocol at C.
A grade describes the human evidence for a named use. It is not advice, and it is not a judgment on any individual prescription. How the letters are decided →
Who responds: this record's trial reading reports no subgroup that identifies who responds.
The trial that would change this grade.
A positive trial of this shape, supported by further trials, would move this entry to B.
Why the current trials fall short
The one positive trial had 30 participants, ran 16 weeks and was led by a researcher at a mushroom producer, and the follow-up trial improved one test of three. An independent trial large enough to detect a real effect on daily life is what would move the letter.
Why people believe itTwo human sources; no published case reports of benefit; one report of harm.
The case for lion's mane is that compounds in this mushroom, hericenones and erinacines, make nerve cells produce nerve growth factor in laboratory work, and that it has a long history as a food and traditional remedy in East Asia. Small trials in older adults found better scores on some memory tests. It is sold for focus, memory and mood.
What supporters point to, and what each source actually shows. None of it is enough to move this letter higher; the trial described above under Evidence wanted is what would.
- Human trial, a different useIn adults with mild Alzheimer's disease, 49 weeks of a mycelium extract enriched in erinacine A gave better cognitive and daily living scores than placebo. A pilot trial of a mycelium product, a different form from the fruiting body powder most products contain. PMID 32581767
- Human trial, a different useIn 41 healthy young adults, a single 1.8 g dose sped up one attention task at 60 minutes, and 28 days of use showed a trend toward less stress that did not reach significance. A small pilot with several null results. PMID 38004235
A case report describes what happened to one or a few patients. It cannot show the treatment caused the change, and reports of success are published more often than reports of failure.
A PubMed search in October 2026 found no published case report of benefit for this use.
- A woman with colorectal cancer developed serious liver injury while taking capsules of mushroom powder containing lion's mane together with another mushroom, Agaricus blazei, and her chemotherapy was canceled. Two mushrooms were involved, so the part played by lion's mane cannot be separated. PMID 39223928
Searched PubMed, October 2026: 4 case report record(s) returned. One describes harm from capsules containing lion's mane with another mushroom, and is listed. The other three match the search terms by name only: a lion's mane jellyfish sting, a laboratory culture study and a brain surgery series.
How this letter has changed · latest: October 2026 · Corrected
The record typed its endpoint as self-report and called measured cognitive tests surrogates; Mori et al. (Phytotherapy Research, 2009; PMID 18844328) used a clinician-administered scale and Saitsu et al. (Biomedical Research, 2019; PMID 31413233) measured tests, which are functional outcomes under the written rule, so the type is corrected. Saitsu is restated as partial: one of three tests improved. The best-use line listed nerve growth factor, neuroplasticity, mood and nerve support, none of which any cited trial measured; it now names what was measured. The dose line led with 500 to 1,000 mg of extract, which no positive trial used; it now states the 3 g/day of powder the trial gave. Added: three null or mostly null trials in healthy young adults (PMIDs 36582308, 38004235, 40276537), the mycelium trial as a different form (Li et al., 2020; PMID 32581767) with its withdrawals for stomach discomfort, nausea and rash now in the caution, the 2025 systematic review A review that searches for every study on a question using a method set in advance, then assesses them together. (Menon et al., Front Nutr, 2025; PMID 40959699), and the lead author's commercial affiliation beside the letter. C unchanged. Applied the written grade definition under the editor's standing instruction of October 2026 (Arnold Sandlow, D.C.).PMID 18844328 PMID 31413233 PMID 32581767 PMID 40959699
Every change to a letter on this site is dated and published. The full evidence log →
Commercial disclosure
EBL earns no commission on any supplement it grades. A purchase made through the dispensary link below pays EBL nothing, the practitioner discount goes to you in full. The dispensary is Fullscript, a practitioner dispensary, and many of the professional-grade brands in it are sold mainly through practitioners rather than in health food stores. Grades are assigned by published rubric before any commercial relationship exists and are never influenced by one. Full disclosure.
The positive trial gave about 3 g/day of fruiting-body dry powder tablets (four 250 mg tablets three times daily) for 16 weeks (Mori 2009, PMID 18844328); it was raw powder, not a standardized extract. The 500 to 1,000 mg extract doses commonly sold were not used in any positive chronic trial; the one chronic trial near 1,000 mg/day used an erinacine-enriched mycelium product in mild Alzheimer's disease (Li 2020, PMID 32581767).
Fruiting body extract (not mycelium on grain) has higher beta-glucan and hericenone content. Standardized extract and raw powder are not equivalent.
The 2009 trial gave four 250 mg tablets three times a day (PMID 18844328). Its summary does not state a time of day or whether the tablets were taken with meals.
Checked against the published summary; the full paper could not be read. What the cited trials did, not a schedule. Every supplement, by trial timing →
Mushroom allergy. Allergic rhinitis and dermatitis have been reported with prolonged use, and there are case reports of more severe reactions. Pregnancy, on absence of data. Stomach discomfort, nausea and skin rash led four participants to withdraw from the 49-week mycelium trial (Li 2020, PMID 32581767); a 2025 systematic review lists stomach discomfort, headache and allergic reactions (PMID 40959699).
Anticoagulants and antiplatelets: mild antiplatelet activity has been reported in laboratory work, so this is a mechanistic caution. Diabetes medication: additive glucose lowering has been reported in animals. Otherwise a low interaction profile, mostly because little has been looked for.
Mechanism-based, no human interaction study located. The drug interactions described for Lion's Mane Mushroom are mechanism-based. A PubMed search for human interaction, pharmacokinetic or co-administration studies pairing it with anticoagulant, antiplatelet returned no results in August 2026. The caution stands on pharmacology, not on a trial, and is labeled as such. Basis: pharmacological mechanism, not a human study. Searched PubMed in August 2026: 2 queries, 0 human results.
A measured cognitive test (MoCA or MMSE) at baseline and 12 to 16 weeks, which is what the trials used; no mood or nerve outcome was measured in any cited trial.
Primary evidenceSeven papers, each linked to its PubMed record.
Mori et al. (Phytotherapy Research, 2009; PMID 18844328): randomized double-blind trial, 30 adults aged 50 to 80 with mild cognitive impairment, about 3 g/day of fruiting-body powder for 16 weeks; clinician-administered HDS-R cognitive scores higher than placebo at weeks 8 to 16 and lower again four weeks after stopping. The lead author's affiliation is the mushroom laboratory of a commercial mushroom producer; funding is not stated. Saitsu et al. (Biomedical Research, 2019; PMID 31413233): 31 healthy older adults, fruiting body for 12 weeks; the Mini-Mental State Examination improved while the Benton visual retention and verbal paired-associate tests did not, a partial result rather than a confirmation, at a dose the abstract does not state. Null or mostly null in healthy young adults: Grozier et al. (Int J Exerc Sci, 2022; PMID 36582308), 10 g/day for 4 weeks; Docherty et al. (Nutrients, 2023; PMID 38004235), 1.8 g/day for 28 days, faster Stroop after a single dose and otherwise null; Surendran et al. (Front Nutr, 2025; PMID 40276537), single 3 g dose of extract, null on composite cognition and mood. Different form: Li et al. (Front Aging Neurosci, 2020; PMID 32581767), erinacine-enriched mycelium 1,050 mg/day for 49 weeks in mild Alzheimer's disease, MMSE and daily-living scores better than placebo, maker-run; four participants withdrew for abdominal discomfort, nausea or rash. Menon et al. (Front Nutr, 2025; PMID 40959699): systematic review of five randomized trials; pooled MMSE gain about 1.2 points from one trial and one pilot; side effects listed include stomach discomfort, headache and allergic reactions. Grade C: one small positive trial on measured cognitive tests in impaired older adults, a partial second, nulls in healthy adults.
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