Lion's Mane

The fruiting body, hou tou gu (“monkey head mushroom”), is used dried in decoction and eaten as food. Chinese medicine counts it among the foods that are also medicines ^{20Reference 20Diling et al. · 2017AnimalExtracts from Hericium erinaceus relieve inflammatory bowel disease by regulating immunity and microbiota — rat modelView study →}.

Its long-standing use is for the stomach and digestion, including gastritis and other gastrointestinal complaints ^{20,21Reference 20Diling et al. · 2017AnimalExtracts from Hericium erinaceus relieve inflammatory bowel disease by regulating immunity and microbiota — rat modelView study →Reference 21Gravina et al. · 2023ReviewHericium erinaceus, a medicinal fungus: evidence in gastrointestinal diseases — reviewView study →}.

In Japan the mushroom is yamabushitake, eaten as food and regarded as a medicinal mushroom since ancient times ^{2Reference 2Saitsu et al. · 2019RCTImprovement of cognitive functions by oral intake of Hericium erinaceus — randomised, double-blind, placebo-controlled trialView study →}.

The most-cited human trial was a 2009 double-blind, placebo-controlled trial in 30 Japanese adults aged 50–80 with mild cognitive impairment. Four 250 mg tablets of 96% dried fruiting-body powder, taken three times daily (3 g a day) for 16 weeks, raised scores on a cognitive function scale compared with placebo at weeks 8, 12 and 16. Four weeks after intake stopped, the scores fell significantly ^{1Reference 1Mori et al. · 2009RCTImproving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment — randomised, double-blind, placebo-controlled trialView study →}.

A 2019 randomised, double-blind, placebo-controlled trial of a fruiting-body supplement for 12 weeks improved scores on the MMSE, but not on the Benton visual retention test or a verbal paired-associate learning test ^{2Reference 2Saitsu et al. · 2019RCTImprovement of cognitive functions by oral intake of Hericium erinaceus — randomised, double-blind, placebo-controlled trialView study →}.

In 41 healthy adults aged 18–45, a single 1.8 g dose made participants faster on the Stroop task 60 minutes later. After 28 days there was a trend toward lower subjective stress (p = 0.051) ^{3Reference 3Docherty et al. · 2023RCTThe acute and chronic effects of lion’s mane mushroom supplementation on cognitive function, stress and mood in young adults — randomised, double-blind, placebo-controlled pilot trialView study →}. In a crossover trial in 18 healthy adults, a single 3 g dose of a 10:1 fruiting-body extract had no overall effect on cognition or mood, with improvement on one pegboard task only ^{4Reference 4Surendran et al. · 2025RCTAcute effects of a standardised extract of Hericium erinaceus on cognition and mood — randomised, placebo-controlled crossover trialView study →}.

A 2025 systematic review pooled MMSE data from one randomised and one non-randomised trial and found a combined mean increase of about 1.2 points ^{28Reference 28Menon et al. · 2025Systematic reviewBenefits, side effects, and uses of Hericium erinaceus as a supplement — systematic reviewView study →}.

Gap: all positive trials are small (n≤30 per arm), mostly in impaired or older cohorts, and use different preparations and dose forms; the healthy-adult data are largely null. No large, long-duration confirmatory RCT exists.

Low-molecular-weight compounds from lion’s mane stimulate the synthesis of nerve growth factor (NGF), the main growth factor for cholinergic neurons ^{7,9Reference 7Spangenberg et al. · 2025Systematic reviewUnveiling the role of erinacines in the neuroprotective effects of Hericium erinaceus — systematic reviewView study →Reference 9Friedman · 2015ReviewChemistry, nutrition, and health-promoting properties of Hericium erinaceus mushroom — reviewView study →}.

The fruiting-body hericenones and the mycelial erinacines both act on NGF. A 2023 study isolated an isoindoline compound and its derivative hericene A, which promoted strong axon outgrowth in cultured hippocampal neurons. The compound worked partly independently of the TrkB receptor, through a pathway converging on ERK1/2 signalling, and mice fed the crude extract or hericene A showed better spatial memory ^{6Reference 6Martínez-Mármol et al. · 2023In vitroHericerin derivatives activate a pan-neurotrophic pathway in central hippocampal neurons — in vitro and mouse studyView study →}.

In cell and rodent models, mycelium extract and the erinacines A and S promoted the maturation of oligodendrocytes, the cells that form myelin, and increased myelin basic protein ^{8Reference 8Huang et al. · 2021In vitroHericium erinaceus mycelium and its small bioactive compounds promote oligodendrocyte maturation — in vitro studyView study →}.

A 2020 randomised, double-blind, placebo-controlled pilot trial in mild Alzheimer’s disease gave three 350 mg capsules of erinacine A-enriched mycelium daily for 49 weeks. The treated group scored better than placebo on CASI, MMSE and daily-living measures and had better contrast sensitivity. Four participants dropped out because of abdominal discomfort, nausea or skin rash (NCT04065061) ^{5Reference 5Li et al. · 2020RCTPrevention of early Alzheimer’s disease by erinacine A-enriched Hericium erinaceus mycelia — randomised, double-blind, placebo-controlled pilot trialView study →}.

A 2025 systematic review found that mycelium formulations and erinacines improved motor, cognitive and depression-like behaviour in animal models. Erinacines A and C also induced Nrf2, a regulator of the antioxidant response ^{7Reference 7Spangenberg et al. · 2025Systematic reviewUnveiling the role of erinacines in the neuroprotective effects of Hericium erinaceus — systematic reviewView study →}.

Gap: the neuroprotection evidence is overwhelmingly preclinical; the single mild-AD RCT is small and used a specific mycelial erinacine A extract that does not correspond to fruiting-body products.

In a 2010 randomised, placebo-controlled trial, 30 women ate cookies containing the fruiting body, or placebo cookies, for 4 weeks. Depression (CES-D) and “indefinite complaint” scores fell from their starting levels in the lion’s mane group. Compared with placebo, two complaint items (“insentive” and palpitations) were lower, and concentration, irritability and anxiety tended to be lower. The authors suggested the effect worked by a route other than NGF ^{10Reference 10Nagano et al. · 2010RCTReduction of depression and anxiety by 4 weeks Hericium erinaceus intake — randomised, placebo-controlled trialView study →}.

A 2019 controlled trial randomised 77 overweight or obese adults on a low-calorie diet to lion’s mane or diet alone. After 8 weeks the lion’s mane group reported less depression, anxiety and sleep disturbance, and had higher circulating pro-BDNF with no change in mature BDNF ^{11Reference 11Vigna et al. · 2019Clinical trialHericium erinaceus improves mood and sleep disorders in patients affected by overweight or obesity — controlled trialView study →}.

In mice, a fruiting-body extract at 20 or 60 mg/kg for 4 weeks reduced anxiety- and depression-like behaviour and increased the birth and survival of new neurons in the hippocampus ^{12Reference 12Ryu et al. · 2018AnimalHericium erinaceus extract reduces anxiety and depressive behaviors by promoting hippocampal neurogenesis in the adult mouse brain — animal modelView study →}.

Gap: both human trials are small and short, and neither was placebo-controlled for the main mood outcome. There is no trial in diagnosed major depression, and the biomarker findings (pro-BDNF up, BDNF unchanged) are hard to interpret.

In rats with a crushed peroneal nerve, daily oral aqueous fruiting-body extract raised Akt, MAPK, c-Jun and c-Fos activity in the dorsal root ganglia and increased protein synthesis in the injured nerve ^{13Reference 13Wong et al. · 2016AnimalHericium erinaceus activates peripheral nerve regeneration after peroneal-nerve crush — rat in vivo studyView study →}.

A 2026 systematic review of 11 studies of mushrooms for peripheral nerve injury included five on lion’s mane. It judged lion’s mane the most promising of the four mushrooms for clinical use and called for clinical research ^{14Reference 14Taib et al. · 2026Systematic reviewApplication of medicinal mushrooms for the treatment of peripheral nerve injury — systematic reviewView study →}.

No human trial has tested lion’s mane for nerve injury or neuropathy, and the effective rodent doses and extracts have no established human equivalent.

In human monocytes, an ethanol extract of lion’s mane reduced the IL-1β, IL-6 and IL-8 released in response to bacterial lipopolysaccharide. Its ergosterol bound to the lipopolysaccharide and reduced IL-8 production ^{15Reference 15Tada et al. · 2022In vitroHericium erinaceus ethanol extract and ergosterol exert anti-inflammatory activities in human monocytes — in vitro studyView study →}.

In rats with chemically induced colitis, lion’s mane extracts lowered NF-κB p65 and TNF-α in the colon and raised IL-10 ^{20Reference 20Diling et al. · 2017AnimalExtracts from Hericium erinaceus relieve inflammatory bowel disease by regulating immunity and microbiota — rat modelView study →}.

Gap: the human-cell data are in vitro only; no clinical trial has measured inflammatory endpoints, and effects are reported for varied extracts and isolated constituents rather than a defined whole-mushroom dose.

Lion’s mane is rich in beta-glucans and other polysaccharides. Chemically modified (selenised) polysaccharide fractions matured mouse dendritic cells through MAPK and NF-κB signalling in vitro ^{16Reference 16Qin et al. · 2017In vitroSelenizing Hericium erinaceus polysaccharides induce dendritic-cell maturation through MAPK and NF-κB signaling — in vitro studyView study →}, and a fruiting-body polysaccharide fraction raised immune signalling molecules in cell assays ^{17Reference 17Yang et al. · 2022In vitroPolysaccharides from Hericium erinaceus fruiting bodies: structural characterization and immunomodulatory activity — in vitro studyView study →}.

In a 2012 mouse study, hot-water and ethanol extracts of the fruiting body, given by injection into the abdomen, protected against liver damage from Salmonella Typhimurium and extended survival. The extracts did not kill the bacteria directly; they increased uptake and killing of the bacteria by macrophages ^{18Reference 18Kim et al. · 2012AnimalHericium erinaceus mushroom extracts protect infected mice against Salmonella Typhimurium-induced liver damage — animal modelView study →}.

Gap: effects are driven by isolated polysaccharide fractions or injected extracts in animal and cell models; there is no human immune-outcome trial.

In rats with acetic-acid-induced gastric ulcers, a fruiting-body polysaccharide reduced the ulcers and lowered IL-6, TNF-α and oxidative markers in the stomach. One active fraction was a β-glucan ^{19Reference 19Wang et al. · 2022AnimalGastroprotective activity of polysaccharide from Hericium erinaceus against acetic-acid-induced gastric ulcer — rat in vivo studyView study →}.

Extracts given for 2 weeks also relieved chemically induced colitis in rats, with changes in immune markers and gut bacteria ^{20Reference 20Diling et al. · 2017AnimalExtracts from Hericium erinaceus relieve inflammatory bowel disease by regulating immunity and microbiota — rat modelView study →}.

A 2023 review collected the preclinical work on gastritis, ulcers and inflammatory bowel disease and noted the mushroom’s long use in traditional Chinese medicine ^{21Reference 21Gravina et al. · 2023ReviewHericium erinaceus, a medicinal fungus: evidence in gastrointestinal diseases — reviewView study →}.

Gap: all efficacy data are rodent or in vitro; no completed human trial confirms a gastroprotective effect.

Lion’s mane extracts and polysaccharides scavenge free radicals in vitro and reduce oxidative-stress markers in animals. A 2012 study of polysaccharide fractions from mycelium grown on tofu whey found strong in vitro antioxidant activity in one fraction, which also protected the liver in mice ^{22Reference 22Zhang et al. · 2012In vitroAntioxidant and hepatoprotective potential of endo-polysaccharides from Hericium erinaceus — in vitro and mouse studyView study →}.

Antioxidant activity runs through the neuroprotective, hepatoprotective and anti-inflammatory findings ^{9Reference 9Friedman · 2015ReviewChemistry, nutrition, and health-promoting properties of Hericium erinaceus mushroom — reviewView study →}.

It is measured chiefly in chemical assays and animal tissue, varies widely with extract and fraction, and has never been shown to translate into a clinical benefit.

An ethanol extract of the fruiting body killed prostate cancer cells in vitro through PI3K/AKT and RAS/MAPK signalling, with little effect on normal cells ^{23Reference 23Atmaca et al. · 2024In vitroHericium erinaceus extract induces apoptosis via PI3K/AKT and RAS/MAPK signaling in prostate cancer cells — in vitro studyView study →}. A 2020 review of erinacine A and related cyathane diterpenoids described their ability to trigger cancer-cell death through reactive oxygen species, in cells and in animals ^{24Reference 24Bailly · 2020ReviewErinacine A and related cyathane diterpenoids: mechanisms underlying their neuroprotection and anticancer activities — reviewView study →}. Isolated erinacine A reduced the invasiveness of gastric cancer cells in laboratory studies ^{28Reference 28Menon et al. · 2025Systematic reviewBenefits, side effects, and uses of Hericium erinaceus as a supplement — systematic reviewView study →}.

Gap: there is no human evidence. The findings are cell-line assays and isolated-compound work, and the doses have no established relationship to oral supplementation.

Mycelium polysaccharide fractions protected the liver in mice, an effect the authors linked to their antioxidant capacity ^{22Reference 22Zhang et al. · 2012In vitroAntioxidant and hepatoprotective potential of endo-polysaccharides from Hericium erinaceus — in vitro and mouse studyView study →}.

This is animal work with no human liver-outcome data, and the active material is an isolated polysaccharide rather than a standard whole-mushroom product.

In rats with streptozotocin-induced diabetes, aqueous fruiting-body extract at 100 and 200 mg/kg for 28 days lowered blood glucose, raised insulin, improved blood lipids and reduced oxidative-stress markers in the liver ^{25Reference 25Liang et al. · 2013AnimalAntihyperglycemic and antihyperlipidemic activities of aqueous extract of Hericium erinaceus in experimental diabetic rats — animal modelView study →}. It is a single rodent model, and effects on glucose or lipids in people are untested.

In mice, lion’s mane polysaccharides at 50–200 mg/kg for 28 days extended swimming time to exhaustion and improved blood and tissue markers of fatigue ^{26Reference 26Liu et al. · 2015AnimalAnti-fatigue activities of polysaccharides extracted from Hericium erinaceus — mouse in vivo studyView study →}. It is one animal study of polysaccharide fractions, with no human trial of exercise capacity or fatigue.

Toxicology. A β-glucan extract of lion’s mane caused no treatment-related harm in rats given up to 2,000 mg/kg/day for 90 days, the highest dose tested, and was not genotoxic in bacterial, cell or mouse tests ^{27Reference 27Chen et al. · 2022AnimalSubchronic toxicity and genotoxicity studies of Hericium erinaceus β-glucan extract preparation — GLP rat studyView study →}. A single 5,000 mg/kg dose of erinacine A-enriched mycelium caused no deaths or signs of toxicity in rats ^{29Reference 29Li et al. · 2018AnimalAcute and developmental toxicity assessment of erinacine-A-enriched Hericium erinaceus mycelia in Sprague-Dawley rats — animal studyView study →}.

Side effects. The side effects reported in human use are stomach discomfort, headache and allergic reactions ^{28Reference 28Menon et al. · 2025Systematic reviewBenefits, side effects, and uses of Hericium erinaceus as a supplement — systematic reviewView study →}. In the 49-week Alzheimer’s trial, four participants dropped out because of abdominal discomfort, nausea or skin rash ^{5Reference 5Li et al. · 2020RCTPrevention of early Alzheimer’s disease by erinacine A-enriched Hericium erinaceus mycelia — randomised, double-blind, placebo-controlled pilot trialView study →}.

Allergy. People with a mushroom or mould allergy should take care. One case of anaphylaxis has been reported after a person ate fresh lion’s mane ^{30Reference 30Muhanna et al. · 2024ReviewALSUntangled #73: Lion’s Mane — reviewView study →}.

Blood-thinning drugs. Hericenone B from lion’s mane inhibited collagen-induced platelet aggregation in rabbit and human platelets in the laboratory ^{31Reference 31Mori et al. · 2010In vitroInhibitory effect of hericenone B from Hericium erinaceus on collagen-induced platelet aggregation — in vitroView study →}. No interaction has been reported in people, but care is sensible alongside anticoagulant or antiplatelet drugs.

Interactions. No human drug-interaction study has been done.