The short answer
The best evidence for lion's mane is for memory in older adults with mild cognitive decline, from three small placebo-controlled trials. Evidence for focus in healthy adults, anxiety and mood is weak and mixed. Claims about nerve repair, immunity, cancer and blood sugar rest on cell and animal studies only.
On this page
How strong is the evidence for each claim?
We grade each claim on the human evidence only, using the four grades explained here. No claim reaches strong evidence, because no result has been confirmed by several good-sized independent trials.
| Claim | Grade | Why |
|---|---|---|
| Memory in older adults with mild decline | Moderate | Three small placebo-controlled trials (30 to 41 people each) found better scores on short memory tests. |
| Focus and thinking in healthy adults | Weak | Five small trials. Two found a quicker response on one or two tasks after a single dose; three found nothing. |
| Anxiety and low mood | Weak | Two small studies found lower scores, but one had no placebo group and the other mostly compared people with themselves. |
| Sleep | Weak | Better sleep scores in one study without a placebo group; a placebo-controlled study found no change. |
| Stomach and gut health | Weak | Lab and animal work, plus studies of mixed supplements that also contained other ingredients. |
| Nerve repair and neuropathy | None | Helped injured nerves recover in rats and eased nerve pain in mice; never tested in people. |
| Immunity | None | Lab and animal studies of its beta-glucans only. |
| Cancer | None | Cell and animal studies only. Never use it in place of cancer treatment. |
| Blood sugar and diabetes | None | Animal studies only. |
Why are there so many claims with so little evidence?
Because the lab findings are genuinely interesting. Lion’s mane compounds make nerve cells produce more nerve growth factor, protect nerve cells under stress and, in rodents, improve memory and speed up recovery from nerve injury. Two systematic reviews of the animal and nerve-injury work describe consistent effects.
But most supplements that look good in rats fail in people, and the human trials of lion’s mane are small: the ten trials we have found involved 338 people between them, and only one had more than 41. Several were funded by, or used products from, companies selling lion’s mane.
Who might reasonably try it?
Based on the trials, the people with the best reason to expect a benefit are older adults with mild memory complaints, taking 1 to 3 g a day of a fruiting body product or a standardised mycelium extract for at least two to three months. Even then the effect, where seen, was modest. Anyone with memory problems should see their GP first, because some causes, such as low vitamin B12, an underactive thyroid or depression, are treatable.
For dose and form, see how to take lion’s mane. Before starting, read the safety guide.
In this section
- Does lion's mane help memory? What the trials show
Three small trials in older adults found modest memory gains with lion's mane. What they tested, the doses used, and why the evidence is still thin.
Moderate - Lion's mane for focus: does it work in healthy adults?
Five small trials tested lion's mane for focus and thinking in healthy adults. Most found no real effect. What was tested, and what the results mean.
Weak - Lion's mane for anxiety and depression: the evidence
Two small studies suggest lion's mane may ease anxiety and low mood, but neither is strong. What they found, their limits and who should be careful.
Weak - Lion's mane for nerve damage and neuropathy: what the evidence shows
Lion's mane helped injured nerves recover in rats and mice, but it has never been tested for nerve damage or neuropathy in people. What the studies found.
None
Common questions
Does lion's mane actually work?
For some things, possibly. Three small trials in older adults with mild memory problems or early Alzheimer's found modest improvements on memory tests. In healthy young adults most trials found little or no effect. Many popular claims have never been tested in people.
How long does lion's mane take to work?
The trials that found memory benefits ran for 12 to 49 weeks, and the first differences showed up at about 8 weeks. Single-dose studies found small changes on one or two tasks within one to two hours, but most measures did not change.
Does lion's mane grow new brain cells?
It makes nerve cells produce more nerve growth factor in lab and animal studies, and some animal studies show new nerve cell growth in the brain. Nobody has shown that it does this in people.
References
- Menon A et al. Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Frontiers in Nutrition, 2025.pubmed.ncbi.nlm.nih.gov
- Cha S et al. A review of the effects of mushrooms on mood and neurocognitive health across the lifespan. Neuroscience & Biobehavioral Reviews, 2024.pubmed.ncbi.nlm.nih.gov
- Mori K et al. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytotherapy Research, 2009.pubmed.ncbi.nlm.nih.gov
- Saitsu Y et al. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomedical Research, 2019.pubmed.ncbi.nlm.nih.gov
- Li IC et al. Prevention of early Alzheimer's disease by erinacine A-enriched Hericium erinaceus mycelia: pilot double-blind placebo-controlled study. Frontiers in Aging Neuroscience, 2020.pubmed.ncbi.nlm.nih.gov
- Tursi A et al. Enhancing oral 5-ASA effectiveness in mild-to-moderate ulcerative colitis through an H. erinaceus-based nutraceutical add-on multi-compound: the HERICIUM-UC trial. Pharmaceutics, 2024.pubmed.ncbi.nlm.nih.gov A multi-ingredient product, so the effect of lion's mane alone cannot be separated.
- Taib NAB et al. Application of medicinal mushrooms for the treatment of peripheral nerve injury: a systematic review. Medical Sciences, 2026.pubmed.ncbi.nlm.nih.gov
- Spangenberg ET et al. Unveiling the role of erinacines in the neuroprotective effects of Hericium erinaceus: a systematic review in preclinical models. Frontiers in Pharmacology, 2025.pubmed.ncbi.nlm.nih.gov
First published 3 November 2026. Spotted an error? Tell us and we'll correct it. Read our editorial policy.