Lion’s mane is the common name for Hericium erinaceus, an edible mushroom found in North America, Europe and Asia and known in Japan as yamabushitake. It is eaten as a food and sold as powders, capsules and extracts, mostly marketed for memory, focus and mood. Interest centers on two groups of compounds, hericenones and erinacines, which raised production of nerve growth factor (NGF, a protein that helps nerve cells survive and grow) in cell and animal studies.
The single most important fact is that the human evidence is thin. A handful of small randomized trials exist, the largest with 77 people, and most tested different products at different doses. Several were run or funded by companies that make lion’s mane products. The results are mixed: some small cognitive or mood effects, several null findings, and no trial large enough to settle whether it works.
This page summarizes what the clinical trials, case reports and regulators report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Type | Edible and medicinal mushroom (Hericium erinaceus) |
| Other names | Yamabushitake; “White Pom Pom” in one occupational case report |
| Parts used | Fruiting body (the visible mushroom) and mycelium (the root-like fungal network, often grown in culture) |
| Key compound groups | Hericenones (fruiting body), erinacines (cultured mycelium), polysaccharides |
| Doses in trials | ≈1–3.2 g/day of powder or capsules; 1.05 g/day of erinacine A-enriched mycelium; 10 g/day in food |
| Half-life | Not established in humans. Erinacine A, one constituent, had an oral half-life of ≈8.2 h in rats |
| Human evidence | Small randomized trials (18–77 participants), 1 dose to 49 weeks |
| US status | Sold as a food and a dietary supplement; FDA does not approve supplements before marketing |
| WADA status | Not named on the 2026 Prohibited List |
What it is
Hericium erinaceus has been used as a medicinal mushroom in traditional Chinese medicine (Saitsu et al., Biomed Res 2019). Supplements are made from two quite different raw materials: the fruiting body itself, or mycelium grown in culture. The two are not chemically equivalent.
| Compound group | Where it is found | What lab studies report |
|---|---|---|
| Hericenones | Isolated from the fruiting body | Reported to stimulate NGF synthesis in cultured astrocytes (support cells in the brain) |
| Erinacines | Isolated from cultured mycelium; diterpenoids | Reported to stimulate NGF synthesis in cultured astrocytes |
| Polysaccharides (glucans) | Both fruiting body and mycelium | Studied mainly for immune and gut effects |
The origins of hericenones and erinacines above follow the summary in Nagano et al., Biomed Res 2010. One trial team noted that the fruiting body does not contain quantifiable levels of erinacines (La Monica et al., Nutrients 2023). A fruiting-body powder and an erinacine-enriched mycelium product are therefore different products, even when both are sold as “lion’s mane.”
The NGF story, and its limits
The best-known mechanism comes from cell and mouse work (Mori et al., Biol Pharm Bull 2008):
- In human astrocytoma cells (a brain tumor cell line), an ethanol extract of lion’s mane raised NGF gene expression and NGF protein secretion. Extracts of three other edible mushrooms did not.
- Medium from those cells promoted nerve-fiber outgrowth in a rat nerve cell line.
- Purified hericenones C, D and E did not raise NGF gene expression in the same system, so the authors concluded the active compounds were something other than hericenones.
- In mice fed a diet containing 5% lion’s mane powder for 7 days, NGF gene expression rose in the hippocampus (a brain region involved in memory).
These are laboratory and animal findings. No study has shown that taking lion’s mane raises NGF in the human brain.
Lion’s mane is one of several “functional” mushrooms in this library, alongside chaga, cordyceps and reishi. These are different species with different chemistry and evidence.
How it behaves in the body
There are no pharmacokinetic studies of lion’s mane in humans. Because it is a mixture of many compounds, it has no single half-life. The available data cover two purified erinacines given to animals, in studies by researchers linked to a company that sells erinacine A-enriched mycelium.
| Measure | Erinacine A, rats (Tsai et al., 2021) | Erinacine S, rats (Hu et al., 2019) | Erinacine A, one pig, IV (Chen et al., 2024) |
|---|---|---|---|
| Oral bioavailability | 24.39% | 15.13% | Not tested |
| Time to peak in plasma (oral) | ≈360 min (6 h) | ≈270 min (4.5 h) | Not applicable |
| Half-life | ≈491 min (≈8.2 h) after oral dosing | ≈440 min (≈7.3 h) after oral dosing | 20.85 min (terminal, IV) |
| Brain | Detected 1 h after oral dosing, peak at 8 h | Distributed to brain and other organs | Found in cerebrospinal fluid from 15 min |
| Main elimination | Feces | 0.1% of dose excreted unchanged in 24 h | Erinacine B identified as a metabolite |
The rat doses were large: about 2.4 g/kg of mycelium extract by mouth, equivalent to 50 mg/kg of each erinacine. These figures show that erinacines can reach the brain in animals. They do not tell us what blood or brain levels a person reaches from a typical capsule.
Regulatory status
In the US, lion’s mane is sold as a food and as a dietary supplement. Under the Dietary Supplement Health and Education Act (DSHEA), FDA does not have the authority to approve dietary supplements before they are marketed (FDA). The part of the mushroom used, the dose and the content of marker compounds are therefore not standardized across products.
Lion’s mane is not named anywhere on the WADA 2026 Prohibited List.
What the research shows
Mild cognitive impairment and Alzheimer’s disease
Two placebo-controlled trials tested lion’s mane in people with cognitive impairment:
| Trial | Population | Product and daily dose | Duration | Main result |
|---|---|---|---|---|
| Mori et al., Phytother Res 2009 | 30 Japanese adults aged 50–80 with mild cognitive impairment | Tablets with 96% fruiting-body powder; 3 g/day | 16 weeks, plus 4 weeks off | Cognitive scores higher than placebo at weeks 8, 12 and 16; fell significantly 4 weeks after stopping |
| Li et al., Front Aging Neurosci 2020 | 49 adults with mild Alzheimer’s disease randomized; 41 completed | Erinacine A-enriched mycelium (5 mg/g erinacine A); three 350 mg capsules | 49 weeks | No significant difference between groups in the two main cognitive tests; better daily-living score and contrast sensitivity |
In the Mori trial, the cognitive scale was based on the Revised Hasegawa Dementia Scale, and laboratory tests showed no adverse effects. The benefit faded once people stopped taking it. The first author was based at a mushroom company’s laboratory.
The Li trial reported results within each group rather than a clear between-group effect:
- MMSE (Mini-Mental State Examination, a 30-point screening test): rose from 21.75 to 23.2 in the lion’s mane group (p = 0.035), with no significant change on placebo. The authors noted that the between-group differences in MMSE and in CASI (another cognitive screening test) were not significant.
- Daily living: the Instrumental Activities of Daily Living score differed at week 49, 6.7 vs 5 (p = 0.012).
- Industry ties: 6 of the 10 authors were affiliated with the company that makes the tested mycelium.
A 2024 review for people with ALS (amyotrophic lateral sclerosis) found no studies of lion’s mane in ALS cells, animals or patients (Muhanna et al., 2024). It described the mild cognitive impairment result as temporary and not yet replicated.
Healthy older adults
One trial randomized 34 healthy Japanese adults over 50 to four 0.8 g supplements of fruiting-body powder a day (3.2 g/day) or placebo for 12 weeks; 31 were analyzed (Saitsu et al., Biomed Res 2019):
| Test | Result vs placebo at 12 weeks |
|---|---|
| MMSE total score | Significantly higher |
| Benton visual retention test (visual memory) | No difference |
| Verbal paired-associate learning (short-term memory for words) | No difference |
Both groups scored close to the MMSE maximum of 30 throughout, so the size of any real-world benefit is hard to judge.
Healthy younger adults
Four small trials in younger, cognitively healthy adults mostly found little or nothing:
| Trial | n | Product and dose | Duration | Result |
|---|---|---|---|---|
| Docherty et al., Nutrients 2023 | 41, aged 18–45 | 1.8 g/day (3 × 600 mg capsules) | Single dose and 28 days | Faster Stroop task 60 min after one dose (p = 0.005); only a trend toward lower stress at 28 days (p = 0.051); other measures null or slightly negative |
| Surendran et al., Front Nutr 2025 | 18, aged 18–35 (crossover) | Single 3 g dose of a 10:1 fruiting-body extract | Single dose | No effect on overall cognition or mood; better on one task (pegboard) at 90 min |
| La Monica et al., Nutrients 2023 | 40, aged 18–50 (crossover) | Single 1 g dose of fruiting body | Single dose | Better on some reaction-time and working-memory measures at 1–2 h |
| Grozier et al., Int J Exerc Sci 2022 | 24, college-age | 10 g/day baked into muffins | 4 weeks | No effect on any cognitive or metabolic outcome (single-blind) |
The Docherty authors called their findings tentative given the small sample. Two of the four trials had industry ties: two authors of the Surendran trial worked for a drinks company that uses lion’s mane in its products, and the La Monica trial was funded in part by an ingredient supplier.
Mood, anxiety and sleep
| Trial | Population | Product and daily dose | Duration | Result |
|---|---|---|---|---|
| Nagano et al., Biomed Res 2010 | 30 women, mean age 41; 26 analyzed | Cookies with 0.5 g fruiting-body powder each, 4 a day (2 g/day) | 4 weeks | Depression and complaint scores fell from baseline in the lion’s mane group; vs placebo, only 2 individual complaint items differed |
| Vigna et al., eCAM 2019 | 77 adults with overweight or obesity on a low-calorie diet | 1.2 g mycelium + 0.3 g fruiting-body extract | 8 weeks | Lower depression, anxiety and sleep-disorder scores; blood pro-BDNF rose, BDNF did not change |
The Vigna trial was not placebo-controlled. The control group (n = 37) followed the diet alone, and 8 people dropped out of the lion’s mane group vs none from control. Without a placebo, the effects of expectation, the diet and dropouts cannot be separated from any effect of the mushroom.
Exercise, muscle and body composition
Lion’s mane is sometimes grouped with recovery supplements. The only exercise trial found that 10 g/day for 4 weeks did not change fat-burning during exercise, markers of cardiorespiratory fitness, or cognition under fatigue (Grozier et al., 2022). None of the human trials described on this page measured muscle mass, strength or recovery from training.
What systematic reviews conclude
A 2025 systematic review included 5 randomized trials and 3 pilot trials (Menon et al., Front Nutr 2025). Pooling MMSE results from just two of these studies gave a weighted mean increase of 1.17 points in the lion’s mane groups. That figure rests on two small studies that used different products in different populations.
Side effects and risks
In clinical trials
The trials were short and small, so they could only detect common side effects:
- In the 49-week Alzheimer’s trial, 4 participants dropped out because of abdominal discomfort, nausea or skin rash; no other adverse events were reported (Li et al., 2020).
- In the 16-week mild cognitive impairment trial, laboratory tests showed no adverse effects (Mori et al., 2009).
- The 2025 systematic review listed headache, stomach discomfort, diarrhea and frequent menstrual periods (epimenorrhea) as side effects reported across studies (Menon et al., 2025).
Allergic and immune reactions
The most serious reports involve allergy or immune reactions:
- Lung injury. A 63-year-old Japanese man developed acute respiratory distress syndrome, a severe lung failure, after taking a lion’s mane extract sold as a diet food (Nakatsugawa et al., Intern Med 2003). A lymphocyte stimulation test (a blood test of immune reaction) reacted strongly to the extract. He needed mechanical ventilation and recovered after high-dose steroids.
- Anaphylaxis. One anaphylactic reaction has been reported after eating fresh lion’s mane (Muhanna et al., 2024).
- Skin. Occupational allergic contact dermatitis has been reported from handling the mushroom (Maes et al., Contact Dermatitis 1999).
These are single case reports, so they cannot give a rate. They do show that people who react to mushrooms may also react to lion’s mane.
Animal toxicology
In a 13-week study, rats fed erinacine A-enriched mycelium at up to 2,625 mg/kg body weight a day showed no deaths and no toxic effects on blood tests or tissue examination (Lee et al., Int J Med Mushrooms 2019). This was industry-linked rat data and does not establish long-term safety in people.
Interactions and who should be cautious
We found no published human drug-interaction studies of lion’s mane. Groups for whom there is no safety evidence:
- people with known mushroom allergies, given the case reports above;
- pregnant or breastfeeding women, who were excluded from trials such as the Saitsu study;
- people taking other supplements or medicines, since multi-ingredient products are common and interactions have not been studied.
Quality and product differences
Products sold as lion’s mane vary widely, and trial results with one product may not apply to another. The trials on this page alone used:
- whole fruiting-body powder (Mori et al., 2009; Saitsu et al., 2019);
- a 10:1 concentrated fruiting-body extract (Surendran et al., 2025);
- mycelium enriched to 5 mg/g erinacine A (Li et al., 2020);
- a blend that was 80% mycelium and 20% fruiting-body extract (Vigna et al., 2019).
Because the fruiting body and the mycelium differ in their main compounds, a label that says only “lion’s mane” does not tell a buyer which material, or how much of any marker compound, a product contains.
Key takeaways
- An edible mushroom with two kinds of products. Fruiting-body products and cultured-mycelium products differ in their key compounds: hericenones in the fruiting body, erinacines in the mycelium.
- The NGF mechanism is lab and animal data. Extracts raised NGF in cell culture and in mice. No study has shown the same in the human brain.
- Small, mixed human trials. Modest cognitive gains appeared in older adults with mild impairment, but faded after stopping or did not separate clearly from placebo. Trials in healthy young adults were mostly null.
- No evidence for muscle or recovery. The one exercise trial, at 10 g/day for 4 weeks, found no effect, and no trial has measured muscle or strength.
- Usually well tolerated, but allergy is possible. Trials reported mainly stomach upset and rash. Rare case reports describe severe lung injury, anaphylaxis and contact dermatitis.
- Unstandardized supplement. It is not FDA-approved, products differ in material and dose, and it is not on the WADA 2026 list.
Sources
- Mori K, Inatomi S, Ouchi K, et al. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother Res. 2009;23(3):367–372. PubMed.
- Saitsu Y, Nishide A, Kikushima K, et al. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomed Res. 2019;40(4):125–131. PubMed.
- Li IC, Chang HH, Lin CH, et al. Prevention of early Alzheimer’s disease by erinacine A-enriched Hericium erinaceus mycelia pilot double-blind placebo-controlled study. Front Aging Neurosci. 2020;12:155. PubMed; PMC.
- 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;15(22):4842. PubMed.
- Surendran G, Saye J, Binti Mohd Jalil S, et al. 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;12:1405796. PubMed.
- La Monica MB, Raub B, Ziegenfuss EJ, et al. Acute effects of naturally occurring guayusa tea and Nordic lion’s mane extracts on cognitive performance. Nutrients. 2023;15(24):5018. PubMed.
- Grozier CD, Alves VA, Killen LG, et al. Four weeks of Hericium erinaceus supplementation does not impact markers of metabolic flexibility or cognition. Int J Exerc Sci. 2022;15(2):1366–1380. PubMed.
- Nagano M, Shimizu K, Kondo R, et al. Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake. Biomed Res. 2010;31(4):231–237. PubMed.
- Vigna L, Morelli F, Agnelli GM, et al. Hericium erinaceus improves mood and sleep disorders in patients affected by overweight or obesity: could circulating pro-BDNF and BDNF be potential biomarkers? Evid Based Complement Alternat Med. 2019;2019:7861297. PubMed.
- Menon A, Jalal A, Arshad Z, et al. Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Front Nutr. 2025;12:1641246. PubMed.
- Muhanna M, Lund I, Bromberg M, et al. ALSUntangled #73: Lion’s Mane. Amyotroph Lateral Scler Frontotemporal Degener. 2024;25(3-4):420–423. PubMed.
- Mori K, Obara Y, Hirota M, et al. Nerve growth factor-inducing activity of Hericium erinaceus in 1321N1 human astrocytoma cells. Biol Pharm Bull. 2008;31(9):1727–1732. PubMed.
- Tsai PC, Wu YK, Hu JH, et al. Preclinical bioavailability, tissue distribution, and protein binding studies of erinacine A, a bioactive compound from Hericium erinaceus mycelia using validated LC-MS/MS method. Molecules. 2021;26(15):4510. PubMed.
- Hu JH, Li IC, Lin TW, et al. Absolute bioavailability, tissue distribution, and excretion of erinacine S in Hericium erinaceus mycelia. Molecules. 2019;24(8):1624. PubMed.
- Chen YY, Lin TW, Li IC, et al. A pilot pharmacokinetic and metabolite identification study of erinacine A in a single landrace pig model. Heliyon. 2024;10(18):e37850. PubMed.
- Nakatsugawa M, Takahashi H, Takezawa C, et al. Hericium erinaceum (yamabushitake) extract-induced acute respiratory distress syndrome monitored by serum surfactant proteins. Intern Med. 2003;42(12):1219–1222. PubMed.
- Maes MF, van Baar HM, van Ginkel CJ. Occupational allergic contact dermatitis from the mushroom White Pom Pom (Hericium erinaceum). Contact Dermatitis. 1999;40(5):289–290. PubMed.
- Lee LY, Li IC, Chen WP, et al. Thirteen-week oral toxicity evaluation of erinacine A-enriched lion’s mane medicinal mushroom, Hericium erinaceus (Agaricomycetes), mycelia in Sprague-Dawley rats. Int J Med Mushrooms. 2019;21(4):401–411. PubMed.
- Food and Drug Administration. Questions and answers on dietary supplements. FDA.
- World Anti-Doping Agency. The 2026 Prohibited List. In effect from January 1, 2026. WADA.