Lion’s Mane Mushroom Benefits: What Human Studies Show

Lion’s mane (Hericium erinaceus) is an edible mushroom used in East Asian medicine, and it is sold as capsules, powders and liquid extracts. Human studies are small and mixed: some report modest changes in memory tests, mood, stress or task speed, and none shows that it prevents dementia. A 2025 narrative review says clinical validation remains limited.

Quick facts from the studies

Does lion’s mane help memory and thinking?

The MSK herb summary lists improving memory as a studied use. It says limited clinical data suggest lion’s mane may improve memory in overweight individuals, in people with mild cognitive impairment and in older adults. Terms like placebo, double-blind and p-value are explained in ingredient evidence vs marketing claims.

Mild cognitive impairment

A 2009 double-blind, placebo-controlled trial in Japan enrolled 30 adults aged 50 to 80 with mild cognitive impairment. Half took the mushroom and half a placebo for 16 weeks. Double-blind means neither the participants nor the researchers knew who got which. The mushroom group scored significantly higher than the placebo group on a cognitive scale at weeks 8, 12 and 16. Four weeks after stopping, scores had dropped significantly. The authors reported no adverse effect in laboratory tests.

Older adults

A 2019 randomized, double-blind, placebo-controlled trial gave older adults supplements containing the fruiting body for 12 weeks. Oral intake significantly improved scores on the Mini-Mental State Examination, a widely used test of thinking and memory. The authors speculate that compounds such as hericenones play a role. They describe the intake as a ‘safe and convenient method for dementia prevention’, but that is their view. The trial measured test scores, so it cannot show that dementia was prevented.

MSK also cites a 2022 four-week study that found no impact on markers of metabolic flexibility or cognition.

Early Alzheimer’s disease

MSK cites a pilot study of erinacine A-enriched mycelia in patients with mild Alzheimer’s disease. A pilot is a small first test. The study’s title uses the word ‘prevention’, but a pilot cannot show that a disease was prevented.

Does lion’s mane help mood, depression or anxiety?

MSK lists improving mood and reducing stress among the uses people seek, and notes that some uses have not been studied. The most direct trial is a 2010 placebo-controlled study of 30 women, randomly assigned to lion’s mane cookies or placebo cookies for four weeks. Within the lion’s mane group, depression and general-complaint scores were significantly lower after four weeks. On two items of a complaints index, the lion’s mane group scored lower than the placebo group, and three other items tended the same way. The authors suggest the mechanism may differ from the nerve growth factor pathway.

A 2025 systematic review states that the mushroom is effective in improving symptoms of anxiety and depression. It draws on five randomized trials, three pilot trials and 15 laboratory studies.

Does it help focus, speed or stress in healthy adults?

A 2023 randomized, double-blind, placebo-controlled pilot enrolled 41 healthy adults aged 18 to 45. One dose of 1.8 g made participants faster on a Stroop task, a timed word and color attention test, at 60 minutes (p = 0.005). After 28 days, the authors saw a trend toward less subjective stress (p = 0.051), which falls short of the usual cutoff. The authors describe the findings as tentative because the sample was small.

A 2023 crossover trial had each participant take one dose of 1 g Nordic-grown lion’s mane, a 650 mg guayusa extract or a placebo, on separate visits. Lion’s mane improved attempts on a Serial 7s task, reaction time on an N-Back task and reaction time on a Go task. It improved ratings of ‘happiness compared to peers’ and ‘getting the most out of everything’ at one hour. The guayusa extract gave greater ratings than lion’s mane for mental clarity and focus.

If you are comparing mushrooms with other supplements studied for stress, the ashwagandha benefits evidence page covers how those human trials are read.

Does it give you a buzz?

The trials measured task speed, reaction time and mood ratings, not a buzz or high. The trials report changes on specific measures, not on the size of any real-world effect. If you feel unwell after a dose, compare what you feel with the side effects listed in the safety section below.

How long does lion’s mane take to work?

The trials tested two windows. Single doses were measured at 60 minutes in the 2023 pilot and at one and two hours in the 2023 crossover. Ongoing use was measured at 4, 12 and 16 weeks. In the 2009 memory trial, scores rose with the length of use and dropped after stopping. These are the windows the studies tested, not a timeline you can count on.

Is lion’s mane different for men and women?

The 2010 mood trial enrolled 30 women and measured menopausal symptoms. The 2009 memory trial enrolled men and women aged 50 to 80. No sex-specific benefit is established in these trials.

Lion’s mane and ADHD

None of the trials described on this page is reported as studying people with ADHD, so they do not show whether lion’s mane affects ADHD symptoms. If ADHD is why you are asking, talk with the clinician who manages it before you start any supplement.

Is lion’s mane proven to work?

No. It has been studied in people, and some trials report small effects on specific measures, but the studies are small, short and mixed. The 2025 narrative review calls for large clinical trials. Until those are done, the most accurate description is that lion’s mane is studied, not proven.

Doses used in studies

These are the amounts researchers used, not recommended amounts. A clinician can advise what, if anything, suits you.

Safety, side effects and medicine interactions

MSK says lion’s mane is generally safe in food and tea, but supplements are stronger than the herb you would cook with, and they can interact with some medicines. The side effects reported in these studies and pages are below.

For a serious allergic reaction, WebMD advises stopping lion’s mane and getting help right away. For too much taken, call 911 or Poison Control at 800-222-1222.

Is lion’s mane hard on the liver?

It lists kidney or liver problems among the conditions to discuss with a clinician before use.

Drug interactions

WebMD says the interactions between lion’s mane and medicines are not fully understood, and that research on drug interactions is incomplete. It lists no known interactions with foods or drinks, and says it is unknown whether alcohol affects lion’s mane. In the 2023 crossover, the abstract says the guayusa extract uniquely raised blood pressure from baseline. Lion’s mane is not named as the cause. Ask your prescriber or pharmacist before combining lion’s mane with any prescription medicine. Lion’s mane is not a substitute for a prescribed medicine.

Who should talk to a clinician first?

• Anyone taking prescription or over-the-counter medicines, vitamins or other supplements. WebMD says to tell your provider about all of them.
• People with a mold or mushroom allergy, who WebMD says may face a higher risk of an allergic reaction.
• People with asthma, or with kidney or liver problems.
• People who are pregnant, planning pregnancy or breastfeeding. WebMD says it is not known whether lion’s mane affects pregnancy or passes into breast milk.
• Anyone allergic to lion’s mane, monkey head mushroom, yamabushitake or any ingredient in a product. WebMD says these people should not take it.

What is still unknown?

• Most trials are small, enrolling 30 to 41 people, and mostly short. The 2025 review calls for large trials and standardized extraction methods.
• Results are mixed. A 2022 four-week study cited by MSK found no impact on cognition, and the 2023 pilot’s stress result missed the usual cutoff.
• Product amounts vary. WebMD says chemical amounts change with growing area, weather, harvest time and processing, so switching bottles may change the effects.
• Most research has been on the fruiting body, not the mycelia.
• The FDA has not reviewed lion’s mane for safety and effectiveness, and has not tested products to confirm their labels, according to WebMD.
• Cancer: the 2025 systematic review states the mushroom is effective in ‘preventing and alleviating cancer’, while MSK says there are no studies in humans that show anti-cancer effects. Read the review’s cancer claim alongside MSK’s view.
• The 2023 pilot’s product came from the company that supplied it, which had no role in the design, data analysis, writing or decision to publish.

How to read a lion’s mane label

By ClinicalStudyConnect.com Research Desk