Lion's Mane: what the human studies actually say (2026)
Lion's Mane gets called the brain mushroom a lot. It's a shaggy white mushroom that grows on hardwood trees, it's eaten in Chinese and Japanese cooking, and it's now in coffees, capsules and gummies all over the UK. So how much of the brain reputation comes from studies in people?
Less than the marketing suggests, and more than nothing. There are a handful of small human trials. We've read the three that come up most, and here's what each one measured.
The quick version
| Study | People | What they took | Main result | The catch |
|---|---|---|---|---|
| Mori et al., 2009 | 30 adults aged 50 to 80 with mild cognitive impairment | Lion's Mane powder tablets daily for 16 weeks | Higher scores on a cognitive function scale than placebo at weeks 8, 12 and 16 | Scores dropped back four weeks after stopping |
| Nagano et al., 2010 | 30 women | Cookies containing Lion's Mane daily for 4 weeks | Lower depression and general complaint scores than placebo | Concentration and anxiety changes weren't statistically significant |
| Docherty et al., 2023 | 41 healthy adults aged 18 to 45 | 1.8g Lion's Mane a day, tested after one dose and after 28 days | Faster on the Stroop test 60 minutes after a single dose | Most other memory and attention tests showed no difference from placebo |
Mori et al., 2009: older adults with memory problems
This is the study most often cited, published in Phytotherapy Research. Thirty Japanese adults aged 50 to 80, all with mild cognitive impairment, took either Lion's Mane tablets or placebo tablets every day for 16 weeks. The trial was double blind, so neither the participants nor the researchers knew who had what.
The Lion's Mane group scored higher on a standard cognitive function scale at weeks 8, 12 and 16. Four weeks after they stopped, their scores had fallen back.
Two things stand out. The people in it already had memory problems, so the result may not apply to healthy adults. And the fall after stopping suggests any effect only lasts while you keep taking it, which is useful to know either way.
Nagano et al., 2010: mood in women
Published in Biomedical Research, this small trial gave 30 women cookies made with Lion's Mane, or placebo cookies, for four weeks. The Lion's Mane group reported lower depression scores and fewer general complaints on questionnaires. Their concentration and anxiety scores moved the right way too, but the differences were small enough that they could have been chance.
Eating Lion's Mane baked into a biscuit is a very different dose and form from an extract, which makes the result hard to compare with modern supplements.
Docherty et al., 2023: healthy young adults
The most recent of the three, published in Nutrients, and the most carefully designed. Forty one healthy adults aged 18 to 45 took 1.8g of Lion's Mane a day or a placebo. They did a battery of memory and attention tasks after the first dose and again after 28 days.
Sixty minutes after a single dose, the Lion's Mane group was faster on the Stroop test, a classic focus task where you name the colour of a word while ignoring what the word says. After 28 days there was a trend towards lower stress scores.
Most of the other tests showed no difference from placebo. The authors called it a pilot study and said bigger trials were needed. That's an honest summary, and we'd put it the same way.
What the lab studies add
Much of the Lion's Mane excitement comes from lab and animal work on two groups of compounds, hericenones and erinacines. In cell studies, they have encouraged the production of nerve growth factor, a protein involved in growing and maintaining nerve cells. Mouse studies have looked at memory and nerve repair.
These results are interesting, and they explain why researchers keep studying the mushroom. They don't show what happens when a person eats a gummy, because the amounts, the delivery and the biology are all different.
Questions nobody has answered yet
- What's the right amount? The three trials used powder, cookies and 1.8g of mushroom, and nobody has compared doses head to head.
- Fruiting body, mycelium or extract? Different products contain different amounts of hericenones and erinacines, and the trials don't settle which form works best.
- Does it help people without memory problems over months? The longest trial in healthy adults ran for 28 days.
We'd like to see a trial of 200 or more healthy adults over six months. As far as we know, nobody has run one.
What we say about Lion's Mane
Starshroooms contains Lion's Mane as a 2:1 extract, alongside five other mushrooms, full spectrum Panax Ginseng, Vitamin B5 and iodine. None of the trials above tested Starshroooms.
UK rules allow no health claims for Lion's Mane, so we don't make any. The claims we can make come from the nutrients: iodine contributes to normal cognitive function, and Vitamin B5 contributes to the reduction of tiredness and fatigue.
Every study in this article is linked from our research page, with what it measured and where it falls short.
