Lion's Mane Benefits: What the Human Studies Actually Show (UK Guide)
What lion's mane is, what the small human trials on memory and focus found, the doses they used, what is only lab evidence, and how it compares with other brain supplements sold in the UK.
By the GUUDIES Editorial Team · Updated 26 October 2026 · Sources listed at the end.
Disclosure: GUUDIES sells a daily pouch that includes a mushroom gummy containing lion's mane. We have set out the evidence as it is, including where it is weak.
This guide brings together our two earlier lion's mane articles into one evidence explainer.
The short answer: lion's mane is an edible mushroom with interesting compounds that, in lab and animal studies, affect nerve growth factor. In people, the evidence is a handful of small trials: two in older Japanese adults found better scores on memory tests after 12 to 16 weeks, and one in healthy young adults found little overall change after 28 days. There are no authorised health claims for lion's mane in Great Britain, so it cannot be said to improve memory, focus or brain health.
What is lion's mane?
Lion's mane (Hericium erinaceus) is a white, shaggy mushroom that grows on hardwood trees and has been eaten in East Asia for centuries. It contains two groups of compounds, hericenones (mainly in the fruiting body) and erinacines (mainly in the mycelium), that researchers have studied for their effects on nerve cells.
Lion's mane benefits: what the human studies found
| Study | Who | Dose and length | What it found |
|---|---|---|---|
| Mori et al., 2009 | 30 Japanese adults aged 50 to 80 with mild cognitive impairment | About 3g of dried lion's mane powder a day for 16 weeks | Higher cognitive test scores than placebo; scores fell again 4 weeks after stopping |
| Saitsu et al., 2019 | 31 Japanese adults over 50 | Lion's mane fruiting body powder tablets for 12 weeks | Improved scores on one cognitive screening test compared with placebo |
| Docherty et al., 2023 | 41 healthy adults aged 18 to 45 | 1.8g a day for 28 days | Faster on one task an hour after a single dose; no significant overall improvement after 28 days |
These trials are small, short and mostly in older adults in Japan. Larger, independent studies are needed before anyone can say lion's mane improves memory or focus in the general population.
What about nerve growth factor?
Much of the excitement comes from laboratory work showing that lion's mane extracts can increase nerve growth factor in cell cultures and in animals (for example Lai et al., 2013). Those results are a reason to study it further in people. They are not evidence that taking lion's mane changes the human brain, and claims that it is "the only natural compound" to do this are not supported.
Lion's mane and mood: one small study
A 2010 Japanese study (Nagano et al.) gave 30 women cookies containing lion's mane fruiting body or placebo cookies for four weeks. The lion's mane group scored lower on questionnaires about irritation and anxiety. It was a single small, short study, so it tells us very little on its own, and lion's mane is not a treatment for anxiety or low mood. If you are struggling with your mood, speak to your GP.
How long does lion's mane take to work?
In the two trials that found an effect, the differences appeared after 12 to 16 weeks of daily use, and in one they faded within a month of stopping. If you try it, give it at least three months and judge it honestly.
Is lion's mane safe?
Lion's mane is a food mushroom, and the trials reported few side effects, mostly mild stomach upset. Avoid it if you are allergic to mushrooms. Speak to your GP or pharmacist first if you are pregnant, breastfeeding, take regular medication (including blood thinners) or have a medical condition. Lion's mane is not a treatment for dementia or any other neurological condition.
Fruiting body or mycelium?
Lion's mane supplements are made from the fruiting body (the visible mushroom), the mycelium (the root-like network) or both. Mycelium is often grown commercially on rice or oats, and some "mycelium on grain" products contain a lot of grain starch alongside the mushroom. On a label, words such as "myceliated grain" or "mycelial biomass" usually mean this. The human trials in the table above used fruiting body material.
Lion's mane vs other brain supplements in the UK
If you are comparing brain supplements, it helps to know which ingredients carry authorised health claims in Great Britain and which do not.
| Ingredient | Authorised claim related to the brain or mind |
|---|---|
| Iodine, zinc, iron | Contribute to normal cognitive function |
| Vitamins B6, B12, niacin, vitamin C | Contribute to normal psychological function and the reduction of tiredness and fatigue |
| Omega-3 DHA | Contributes to maintenance of normal brain function (at 250mg a day) |
| Lion's mane | None authorised |
What to look for in a lion's mane supplement
- Part of the mushroom: fruiting body, mycelium or both. The trials above used the fruiting body.
- Amount: the trials used about 1.8g to 3g of powder a day. Many gummies and capsules contain less.
- Extract ratio: if a label gives "equivalent" amounts, check the actual milligrams of extract.
- Claims: be wary of products promising better memory or focus from lion's mane. No such claim is authorised in Great Britain.
Lion's mane in GUUDIES
Our Mushroom Mix gummy lists 1000mg of lion's mane per gummy alongside shiitake, chaga, reishi and cordyceps. That is less than the amounts used in the trials above, so we do not suggest you will see the same results. It is pectin based, vegan, has about 0.4g of sugar and is one of six gummies in the daily pouch. The Daily Greens+ gummy in the same pouch provides vitamin B6 and vitamin B12, which contribute to normal psychological function and the reduction of tiredness and fatigue.
Common questions
What are the benefits of lion's mane?
Small trials in older adults found better scores on memory tests after 12 to 16 weeks, and lab studies show effects on nerve growth factor. The evidence is early, and no health claims are authorised for lion's mane in Great Britain.
Does lion's mane help focus?
One 2023 trial in young adults found faster performance on one task an hour after a dose, but no significant overall improvement after 28 days. There is not enough evidence to say it improves focus.
How much lion's mane should I take?
The human trials used about 1.8g to 3g of dried powder a day. Follow the label of your product and do not exceed it.
Is lion's mane a magic mushroom?
No. It contains no psilocybin and is not psychoactive. It is an edible mushroom.
Who should not take lion's mane?
Anyone allergic to mushrooms. Check with your GP first if you are pregnant, breastfeeding or on regular medication.
Sources
- 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
- Saitsu Y et al. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomedical Research 2019. PubMed
- 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. PubMed
- Nagano M et al. Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake. Biomedical Research 2010. PubMed
- Lai PL et al. Neurotrophic properties of the lion's mane medicinal mushroom, Hericium erinaceus. International Journal of Medicinal Mushrooms 2013. PubMed
- Great Britain nutrition and health claims register. gov.uk
Related reading
- Reishi, chaga and cordyceps: what each mushroom is
- Mushroom gummies UK: a guide
- The GUUDIES Mushroom Mix gummy
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