Research review
Lion's mane: what the research does and doesn't show
A map of the human research on lion's mane: 11 studies of the mushroom alone, four of multi-ingredient products, and three safety reports.
The research does not show that lion's mane improves memory, mood or focus in healthy people. We found one systematic review but no dedicated meta-analysis, and the human studies are small: of 11 studies of lion's mane on its own, the placebo-controlled ones in healthy adults found little or no overall effect. This page lists every human study we found, grouped by outcome.
What the evidence doesn't support
It does not support any dose as effective: studies ranged from 1 g in a single dose to 10 g a day, and the 10 g trial found nothing. It does not support results in people with a diagnosed condition applying to healthy adults, or the reverse. It does not support combining a result from a multi-ingredient product with lion's mane, because those studies cannot separate the ingredients. And it does not show that the nerve-growth effects described in lab work happen in people who take lion's mane; none of the abstracts below reports measuring that. For the narrative, see lion's mane benefits: what the research does and doesn't show. This page is the map.
What the trials found
We searched PubMed on 2 October 2026 for Hericium, lion's mane and yamabushitake combined with trial, review, case-report and observational publication types, and read every abstract below. Doses and forms differ widely: fruiting-body powder, an extract, erinacine A-enriched mycelium, cookies and muffins. Certainty is for the question "did lion's mane change this outcome in this group".
| Study | Population | Dose and form | Duration | Result | Certainty |
|---|---|---|---|---|---|
| Healthy adults: thinking, mood, stress | |||||
| PMID 38004235 (2023) | 41 healthy adults aged 18-45 | 1.8 g a day, form not stated in the abstract | One dose, then 28 days | Quicker on one reaction task at 60 minutes (p = 0.005); stress trend at 28 days not significant (p = 0.051); some null findings | Low |
| PMID 40276537 (2025) | 18 healthy adults aged 18-35 | 3 g, 10:1 fruiting-body extract, single dose | 90 minutes | No effect on overall thinking or mood scores; one pegboard test improved | Low |
| PMID 36582308 (2022) | 24 college-age adults | 10 g a day baked into muffins | 4 weeks | No difference on metabolic flexibility or thinking (all p > 0.05); groups differed at baseline | Low |
| PMID 38140277 (2023) | Healthy participants; number not stated in the abstract | 1 g Nordic-grown lion's mane extract, single dose | 1 and 2 hours | Better on a few quick tasks (Serial 7s attempts, N-back and Go reaction times) and two happiness ratings; placebo also improved focus | Low |
| PMID 33800983 (2021) | 13 healthy adults, no placebo group | Lion's mane powder, dose not stated in the abstract | 7 days | Gut bacteria diversity rose; changes correlated with some blood measures | Very low: tiny, uncontrolled |
| Older adults and diagnosed conditions | |||||
| PMID 18844328 (2009) | 30 adults aged 50-80 with mild cognitive impairment | About 3 g a day: four 250 mg tablets (96% dry powder) three times a day | 16 weeks, 4 weeks follow-up | Higher scores on one scale than placebo at weeks 8, 12 and 16; fell 4 weeks after stopping | Low |
| PMID 31413233 (2019) | Not stated in the abstract | Supplement containing fruiting body; dose not stated | 12 weeks | One of three cognitive tests (MMSE) improved versus placebo; the other two did not | Very low |
| PMID 32581767 (2020) | Patients with mild Alzheimer's disease; number not stated in the abstract | About 1,050 mg a day of erinacine A-enriched mycelium (3 x 350 mg) | 49 weeks | Some cognitive and daily-living scores differed from placebo; four people dropped out for abdominal discomfort, nausea or rash | Low |
| PMID 3932005 (1985) | Patients with chronic atrophic gastritis | Not available: PubMed has no abstract | Not available | A double-blind preliminary report; we could not read its result | Cannot be graded |
| Mood and sleep questionnaires | |||||
| PMID 31118969 (2019) | 77 overweight or obese adults dieting, with mood, sleep or binge-eating complaints | Dose and form not stated; no placebo group described | 8 weeks | Self-rated depression, anxiety and sleep scores fell; one blood marker (pro-BDNF) rose, BDNF did not | Very low |
| PMID 20834180 (2010) | 30 women | Lion's mane cookies, dose not stated | 4 weeks | Two questionnaire scores fell versus before intake; between groups only two sub-items differed | Very low |
| Multi-ingredient products that include lion's mane (cannot be attributed to it) | |||||
| PMID 41097229 (2025) | 599 adults after colonoscopy; retrospective | Lion's mane, butyrate and probiotic combination | Up to 4 weeks | Stomach symptom scores differed between groups; the authors call for controlled studies | Very low |
| PMID 38186311 (2024) | 123 patients with irritable bowel syndrome; retrospective | Probiotics, lion's mane, palmitoylethanolamide and Undaria, one capsule a day | 4 weeks | Stool consistency and pain scores changed over 4 weeks; no placebo group | Very low |
| PMID 39339171 (2024) | Patients with mild-to-moderate ulcerative colitis; retrospective two-arm | Lion's mane-based multi-compound added to standard treatment | 3 and 6 months | Response rates did not differ significantly; remission rates and a stool marker did | Very low |
| PMID 41910467 (2026) | 54 patients with diverticular disease; retrospective | Six-ingredient supplement, daily | 1 month | Bowel frequency and pain scores changed from baseline; no control group | Very low |
| Reviews and safety reports | |||||
| PMID 40959699 (2025) | Systematic review: 5 RCTs, 3 pilot trials, 15 lab studies and others | Varied | 2000-2024 literature | Small cognitive score gains in a few trials; lists stomach discomfort, headache and allergic reactions as possible side effects | Pools very different materials |
| PMID 14714963 (2003) | One 63-year-old man | A lion's mane extract formulation | Taken about 4 months before onset | Severe acute respiratory distress, linked by lab testing to the extract; recovered with treatment | One case |
| PMID 10344494 (1999) | Occupational exposure | Handling the fresh mushroom | Not available | Allergic contact dermatitis; PubMed has no abstract | One case |
| PMID 39223928 (2025) | One 43-year-old woman | Three capsules a day of a lion's mane and Agaricus powder blend | Since November 2023 | Liver tests rose and improved after stopping; the authors attributed it to the Agaricus component | One case, mixed product |
Where the evidence is, and isn't
The evidence is thin and mixed. Of the four placebo-controlled studies in healthy adults, none showed a clear overall gain in thinking or mood: results were limited to a few individual tasks or null, and the one 10 g trial was null. The positive scores come from older adults with mild cognitive impairment or Alzheimer's disease, using different materials, in groups of about 30. It does not exist at all for a fruiting-body-and-mycelium powder at 1,000 mg a day: no study we read tested that. And none of the abstracts we read reports a nerve growth factor measurement in a person.
Questions people ask
Can lion's mane cause diarrhea or constipation?
Neither appears in the abstracts we read. What trials and reviews report is stomach discomfort (the 49-week Alzheimer's pilot lost four people to abdominal discomfort, nausea or rash) and the review lists stomach discomfort, headache and allergic reactions, noting they are commonly unreported (PMID 32581767, PMID 40959699). We cannot give a frequency. See lion's mane side effects.
Is lion's mane safe during pregnancy or breastfeeding, or for kids and toddlers?
We found no study of lion's mane in pregnancy, breastfeeding or children, so no safety statement is possible, and this page gives no guidance on any of them. Ask a doctor first. Please keep supplements out of children's reach.
What about "lion's mane jellyfish weight"?
The lion's mane jellyfish is a sea animal and has nothing to do with the mushroom discussed here.
When to talk to a doctor
Lion's mane is not a treatment for memory loss, dementia, depression, anxiety or any other condition, and nothing here suggests using it in place of care. If you or someone you know has memory problems or low mood, see a doctor. If you take prescription medication or have a mushroom allergy, ask first; see lion's mane and medications and who should not take lion's mane.
Sources
- 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 In a small pilot study of 41 healthy adults, a single 1.8 g dose of lion's mane improved performance on one cognitive test, and 28 days of daily use showed a stress-reduction trend that fell just short of statistical significance; the study's own authors called the results tentative.
- 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 In 18 healthy young adults, one 3 g dose of a 10:1 lion's mane fruiting-body extract did not change overall thinking or mood scores at 90 minutes.
- Four Weeks of Hericium erinaceus Supplementation Does Not Impact Markers of Metabolic Flexibility or Cognition In 24 college-age adults, 10 g a day of lion's mane in muffins for 4 weeks did not change metabolic or thinking measures.
- Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance A single 1 g dose of a lion's mane extract was followed by better scores on a few quick tasks within 2 hours; the abstract does not state the number of participants.
- Influence of Short-Term Consumption of Hericium erinaceus on Serum Biochemical Markers and the Changes of the Gut Microbiota: A Pilot Study In 13 healthy adults, 7 days of lion's mane powder was followed by changes in gut bacteria; there was no placebo group.
- Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial In 30 older adults with diagnosed mild cognitive impairment, about 3 g a day of lion's mane powder for 16 weeks raised one cognitive score, which fell back after stopping.
- Improvement of cognitive functions by oral intake of Hericium erinaceus A 12-week trial of a lion's mane fruiting-body supplement found one of three cognitive tests improved; dose and participants are not in the abstract.
- Prevention of Early Alzheimer's Disease by Erinacine A-Enriched Hericium erinaceus Mycelia Pilot Double-Blind Placebo-Controlled Study In adults with mild Alzheimer's disease, about 1,050 mg a day of an erinacine A-enriched mycelium for 49 weeks scored better than placebo on some tests; four stopped for stomach or skin reasons.
- A double-blind study of effectiveness of hericium erinaceus pers therapy on chronic atrophic gastritis. A preliminary report A 1985 double-blind study of lion's mane in chronic atrophic gastritis exists; PubMed has no abstract, so its dose and result are not available to us.
- Hericium erinaceus Improves Mood and Sleep Disorders in Patients Affected by Overweight or Obesity: Could Circulating Pro-BDNF and BDNF Be Potential Biomarkers? In 77 overweight adults with mood or sleep complaints on a low-calorie diet, 8 weeks of lion's mane came with lower questionnaire scores; dose is not in the abstract.
- Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake In 30 women, 4 weeks of lion's mane cookies were followed by lower depression and complaint scores, but few differences from placebo reached significance.
- Management of Post-Colonoscopy Syndrome with a Nutraceutical Intervention Based on Hericium erinaceus: A Retrospective Two-Arm Multicentre Analysis In a retrospective study of 599 people after colonoscopy, a multi-ingredient supplement containing lion's mane was associated with different stomach symptom scores; lion's mane cannot be separated out.
- Effects of a Nutraceutical Multicompound, with Probiotics, Hericium, PEA, and Undaria in Patients with Irritable Bowel Syndrome In a retrospective look at 123 people taking a multi-ingredient supplement that included lion's mane, scores changed over 4 weeks; the effect of lion's mane alone is unknown.
- Enhancing Oral 5-ASA Effectiveness in Mild-to-Moderate Ulcerative Colitis through an H. erinaceus-Based Nutraceutical Add-on Multi-Compound: The "HERICIUM-UC" Two-Arm Multicentre Retrospective Study In a retrospective comparison in ulcerative colitis, adding a multi-ingredient lion's mane supplement was associated with higher remission rates but not different response rates; lion's mane alone was not tested.
- A multi-compound dietary supplement to improve the well-being of symptomatic uncomplicated diverticular disease In 54 patients taking a six-ingredient supplement that included lion's mane for a month, symptom scores changed from baseline; there was no control group.
- Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review A 2025 review of lion's mane studies listed stomach discomfort, headache and allergic reactions as possible side effects and noted they are commonly unreported.
- Hericium erinaceum (yamabushitake) extract-induced acute respiratory distress syndrome monitored by serum surfactant proteins One man developed severe lung inflammation after taking a lion's mane extract and recovered with treatment; a single case.
- Occupational allergic contact dermatitis from the mushroom White Pom Pom (Hericium erinaceum) A 1999 case report describes allergic contact dermatitis from handling lion's mane mushrooms at work; no abstract is available.
- Grade 3 cytolysis in a patient with metastatic colorectal cancer consuming a mushroom powder-based alternative therapy One woman's liver tests rose after a capsule containing two mushrooms, lion's mane and Agaricus; the authors blamed the Agaricus.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.