Lion's Mane
Lion's mane (Hericium erinaceus) is a food mushroom also sold as a supplement. What small human trials found, what is only lab research, and the safety points to know.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Safety first. Lion's mane is an edible mushroom, and the sources we read describe few harms, but they are not zero. Reported side effects include stomach discomfort, nausea, headache and skin rash, and allergic reactions have been reported. [1][2] Call 911 for swelling of the face or throat or trouble breathing. If you take prescription medicines, are pregnant or breastfeeding, or have an upcoming operation, ask a pharmacist or clinician before using a supplement. See medicine interactions for how to ask.
What it is
Lion's mane is the common name for Hericium erinaceus (Bull.) Pers., an accepted species in the family Hericiaceae. [3] It grows on dead hardwood trees and has long white spines that hang down. It is eaten in East Asian cooking, and supplements are made from the fruiting body (the part above the wood), from mycelium (the thread-like body of the fungus, often grown on grain), or from both. [2] Which part and which extract a product uses matters, because trials used different ones. See fruiting body vs mycelium.Wild mushrooms cannot be safely identified from a description, so this guide does not try. For any wild mushroom that was eaten, call Poison Help at 1-800-222-1222 in the US, and read mushroom poisoning and urgent help.
Traditional use
Traditional use only, not proof. Memorial Sloan Kettering Cancer Center's herb summary says lion's mane has a long history of use in Native American and East Asian medical systems for infections, anxiety, stress and depression. [2] A long history is part of the story of a food; it does not show that a supplement works.What research shows
The table separates what was tested in people from what is only lab work. Every trial listed was small.| Use | What the source found | Strength of evidence | Form and population studied |
|---|---|---|---|
| Memory in mild cognitive impairment | A 16-week trial reported higher scores on a cognitive scale than placebo at weeks 8, 12 and 16. Scores fell again 4 weeks after stopping. [4] | Promising but limited (30 people) | Powder tablets of the mushroom, adults aged 50 to 80 in Japan |
| Memory in older adults | A 12-week trial found one test (MMSE) improved; the other tests were not reported as improved in the abstract. [5] | Promising but limited | Supplements containing fruiting body, Japan |
| Mild Alzheimer's disease | A 49-week pilot trial of erinacine A-enriched mycelium reported better scores than placebo on some scales. Four people dropped out for abdominal discomfort, nausea or rash. [6] | Promising but limited (pilot) | Mycelium capsules, not comparable to fruiting body products |
| Focus and stress in healthy young adults | A single dose (1.8 g) was linked to faster Stroop task performance at 60 minutes; a stress score trend after 28 days did not reach the usual threshold (p = 0.051). [7] A separate 3 g extract dose trial found no overall change in cognition or mood at 90 minutes. [8] | Mixed | 41 and 18 healthy adults; fruiting body |
| Mood in menopausal women | In a 4-week trial of mushroom cookies in 30 women, depression scores were lower than before the cookies, and two complaint items were lower than with placebo. [9] | Insufficient evidence (very small) | Cookies containing the mushroom, women in Japan |
| Cancer | MSK states there are no studies in humans showing it has anti-cancer effects. [2] | Preclinical (cells or animals) only | Laboratory models |
A 2025 systematic review found five randomized trials and several pilot trials, mostly on cognition. It reported a combined average rise of 1.17 points on the Mini-Mental State Examination across one randomized and one pilot trial. [1] A change of that size on a test score does not by itself show that a person would notice a difference in daily life.
"Nerve growth factor" claims come mainly from cell and animal work. MSK describes hericenones and erinacines as promoting nerve growth factor in preclinical studies. [2] Those results are not human outcomes; see lion's mane and nerve growth factor claims. Detailed trial pages: memory and cognition and mood.
Forms and why the form matters
A result from one preparation does not carry over to another. The trials above used powder tablets, fruiting body supplements, cookies, a 10:1 fruiting body extract and erinacine A-enriched mycelium. [4][8][9][6] The authors of the 2025 acute trial note that people usually eat only the fruiting body, in some cases up to 300 g of fresh mushroom at a time. [8] Compare forms on lion's mane forms and study amounts on amounts used in studies. A clinician or pharmacist decides what is right for a person; this page gives trial amounts only to describe the trials.Official statements
The National Cancer Institute's PDQ summary (updated 2024) says the US Food and Drug Administration has not approved medicinal mushrooms as a treatment for cancer or any other medical condition. [10]Frequently asked questions
Does lion's mane improve memory?
Some small trials in older adults with mild cognitive impairment reported higher test scores than placebo, but they were short, small and used different products. [4][5] Trials in healthy young adults were mixed. [7][8] Evidence is promising but limited.
Is lion's mane the same as a "nootropic" or a medicine?
It is a food mushroom sold as a supplement. The sources we read describe it as promoted for cognitive health, mood and immunity, which is a marketing description, not an approved use. [2]
What side effects have been reported?
Abdominal discomfort, nausea and skin rash were reported in a clinical study, and the 2025 review lists stomach discomfort, headache and allergic reactions. [2][1]
Can lion's mane treat cancer?
No. MSK states that there are no human studies showing anti-cancer effects. [2] Anyone in cancer care should tell the oncology team about every product they use.
Is a supplement the same as eating the mushroom?
Not necessarily. Trials used different parts and extracts, so a result for one form does not transfer to another. [8][6] For other mushrooms compared side by side, see the mushrooms A to Z directory.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety in more detail
- Allergy: allergic reactions are listed as a possible side effect in the systematic review. [1] See lion's mane side effects and allergy and mushroom allergy.
- Medicines: interactions were not described in the sources we read for this page. That is not proof of safety. See lion's mane and medicines.
- Pregnancy, breastfeeding and children: not described in the sources we read. See pregnancy, breastfeeding and children.
- Liver, kidney, bleeding and surgery: not described in the sources we read for lion's mane. Tell the surgical team about every supplement before an operation.
- Quality: supplements are not reviewed for batch consistency before sale in the US, and ingredient amounts can vary from lot to lot, according to the National Cancer Institute's mushroom summary. [10] See quality testing and certifications.
References
- Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Front Nutr 2025 Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center, Lion's Mane, About Herbs Read 2026-10-23.
- GBIF Backbone Taxonomy, Hericium erinaceus (Bull.) Pers. Read 2026-10-23.
- Mori 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 Read 2026-10-23.
- Saitsu Y et al. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomed Res 2019 Read 2026-10-23.
- Prevention of Early Alzheimer's Disease by Erinacine A-Enriched Hericium erinaceus Mycelia Pilot Double-Blind Placebo-Controlled Study. Front Aging Neurosci 2020 Read 2026-10-23.
- Docherty S et al. The Acute and Chronic Effects of Lion's Mane Mushroom Supplementation on Cognitive Function, Stress and Mood in Young Adults. Nutrients 2023 Read 2026-10-23.
- Acute effects of a standardised extract of Hericium erinaceus on cognition and mood in healthy younger adults. Front Nutr 2025 Read 2026-10-23.
- Nagano M et al. Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake. Biomed Res 2010 Read 2026-10-23.
- National Cancer Institute, Medicinal Mushrooms (PDQ), Health Professional Version, updated November 6, 2024 Read 2026-10-23.