How Does Lion's Mane Make You Feel? Reports and Trials

Most people feel nothing obvious from lion's mane. It contains no caffeine and no psychoactive compound, and the trials that found anything measured scores on cognitive tests in older adults with mild memory impairment, not feelings.^{1, 9} Among 50 forum threads read in October 2026, about 22 people described clearer thinking or steadier mood, usually from day two or three; about 15 noticed nothing after weeks or months; and about 14 blamed lion's mane for feeling weird, anxious or flat, most of them also taking a medicine, a stack of supplements or a doubled dose. No published study has recorded those reactions, which is not proof they do not happen. The Wellgard mushroom guide covers every species, what lion's mane is good for covers the trials, and lion's mane side effects covers safety in full.

Sources checked on 29 October 2026.

How does lion's mane make you feel?

Usually, like you did before. The reports that describe a change use modest words: "clearer", "less scattered", "short-term memory a bit better". The "nothing" reports are as common after one to three months on 1 to 3 g a day. Neither is a measurement. The trials measured something different: in 30 Japanese adults aged 50 to 80 with mild cognitive impairment, 3 g a day of fruiting-body powder for 16 weeks raised scores on a dementia rating scale from week 8 onwards, and the gain had gone four weeks after they stopped.¹ Lion's mane is not a psychedelic; does lion's mane get you high covers that.

Why do I feel weird after taking lion's mane?

What forum threads report, across our sample: anxiety or panic (five posts), low mood or suicidal thoughts (four), feeling spaced out, unreal or detached from yourself (three), insomnia (two), loss of pleasure, tearfulness and gut upset (one each). What the research holds: trials up to 10 g a day for four weeks and about 1 g a day for 49 weeks reported no serious adverse effects; a 2025 systematic review lists stomach discomfort, headache and allergic reactions as the potential side effects; and a PubMed search pairing lion's mane with anhedonia, depersonalisation or emotional blunting returned no records on 29 October 2026.^{3, 6, 9} If you feel weird, stop taking it; see a pharmacist or GP, or call NHS 111, if it does not settle, and report it to your local authority's trading standards or environmental health team, which works with the Food Standards Agency.¹⁰ Thoughts of harming yourself are urgent whatever the cause: call NHS 111 and choose the mental health option, contact your GP, or ring Samaritans on 116 123.¹¹

Does lion's mane help with brain fog?

No trial has tested it for brain fog, and none has tested it in ADHD. The cognition trials are three small studies in older adults with impairment and four in healthy young adults. In the impaired group: the 30-person, 16-week trial above; a 12-week trial of 31 adults over 50 in which a fruiting-body supplement improved one test score (the MMSE) but not two others; and a 49-week pilot in mild Alzheimer's disease using about 1 g a day of a mycelium standardised to erinacine A, with better MMSE and daily-living scores than placebo.^{1, 2, 3} In healthy adults: 41 people aged 18 to 45 performed one attention task faster an hour after a single 1.8 g dose, with "null and limited negative findings" elsewhere; in a crossover study, 1 g improved a few reaction-time measures but a caffeinated tea extract improved more; 10 g a day in muffins for four weeks changed nothing in 24 adults; and one 3 g extract dose changed no overall score in 18.^{4, 5, 6, 12} The 2025 systematic review pooled one randomised and one pilot trial to a 1.17-point MMSE gain.⁹ So for a 45-year-old with "meno brain" or a 30-year-old who cannot focus: the people studied were not you, and the best trial's effect was a test score that reversed on stopping.

Does lion's mane help menopause brain fog, or brain fog during cancer treatment?

One trial comes close: 30 women with menopausal complaints ate lion's mane cookies or placebo cookies for four weeks; depression and "indefinite complaint" scores fell from their own baselines, but against placebo only two items, "insensitive" and "palpitation", were lower, with concentration, irritation and anxiety "tending" lower.⁷ On UK menopause forums, lion's mane is an aside in a brain-fog conversation whose better-supported answers are HRT, checking B12, thyroid and blood sugar, sleep and exercise; which menopause supplements have evidence and signs of vitamin B12 deficiency cover the checks. The hardest case is the woman on letrozole, anastrozole or tamoxifen after breast cancer, who cannot have HRT. No trial has tested lion's mane alongside any of those medicines, and some trials of fungal beta-glucans changed immune markers in blood tests, which is a laboratory finding, not an authorised claim, so ask the oncology pharmacist first; what are the side effects of mushroom supplements has the medicine table.

Does lion's mane affect mood, anxiety or depression?

The human mood evidence is two small studies, one trend and one null single-dose trial. The 30-woman cookie trial above; an eight-week study of 77 overweight adults with mood, sleep or binge-eating problems on a low-calorie diet, in which depression, anxiety and sleep scores improved, with no control group to separate the diet, the attention and the mushroom; the 41-adult trial's lower subjective stress at 28 days, p = 0.051; and the 18-adult single dose, null for mood.^{4, 7, 8, 12} That is not evidence that lion's mane reduces anxiety or depression; nothing here should change how anyone takes a prescribed antidepressant. Compounds in lion's mane raise nerve growth factor in laboratory and animal studies; this has not been shown to repair nerves or grow brain cells in people.^{7, 9} Cortisol has not been measured in any human lion's mane trial, unlike ashwagandha's (ashwagandha vs lion's mane); the stress trials used questionnaires.⁴

Does lion's mane give you energy, make you sleepy, or change your dreams?

Lion's mane has no caffeine, so any lift is not a stimulant effect; no trial recorded energy, sleepiness, appetite or motivation as an outcome. The reports go both ways, and four posters in our sample described vivid dreams or "dreaming again". The sleep data are the uncontrolled 77-adult study, where sleep scores improved alongside everything else, and the 30-woman cookie trial, which scored sleep quality but reported no sleep result; nobody has measured REM sleep.^{7, 8}

Should you take lion's mane in the morning, at night or before bed?

No trial has compared times of day. The 16-week trial gave its 3 g as tablets three times a day with meals; the healthy-adult trials dosed once in the morning before testing.^{1, 4} Take it with breakfast by default; if it keeps you awake, keep it to the morning; if it makes you drowsy, take it in the evening.

What we don't know

Whether what people report is the mushroom: no trial has asked healthy adults how lion's mane makes them feel, and forum counts are reports, not rates. Whether it changes sleep, dreams, energy or appetite: no controlled trial has scored them as outcomes.^{7, 8} Whether the 28-day stress trend holds in a larger group: its authors asked for caution.⁴

Frequently asked questions

Does lion's mane work immediately, and how long does it take?

Most people feel nothing; those who report a change say day two or three, while the 16-week trial, run by a producer's laboratory, first measured a difference at week 8 and the effect was gone four weeks after stopping.¹ A single 3 g extract dose in 18 adults changed no overall score at 90 minutes in a maker-run 2025 trial.¹²

Can lion's mane cause anxiety?

It is reported, in five posts in our sample, most with another factor present; no trial has recorded it, and the one trial that measured stress found a trend the other way.⁴ Stop if it happens.

Does lion's mane make you tired or sleepy?

No trial has recorded drowsiness as a side effect or measured sleepiness as an outcome: the 2025 review lists stomach discomfort, headache and allergic reactions.^{4, 9} Lion's mane contains no caffeine and nothing that acts as a sedative. If it leaves you drowsy, move it to the evening or stop; tiredness that lasts for weeks is a GP matter whatever you take.

Is lion's mane an antidepressant?

No. Two small studies, one uncontrolled, a non-significant stress trend and a null single-dose trial are the evidence; it is a food, never a substitute for a medicine.^{4, 7, 8, 12} Nor is it addictive: no dependence or withdrawal has been described, see does lion's mane get you high.

Does lion's mane make you hungry?

Appetite has not been measured in any trial; the one study in people with binge eating was uncontrolled.⁸

Sources

1. Mori K, et al. Lion's mane (Yamabushitake) in mild cognitive impairment. Randomised placebo-controlled trial, 30 adults, 16 weeks; run by a producer's laboratory. Phytotherapy Research, 2009. PubMed 18844328.
2. Saitsu Y, et al. Cognitive functions and oral intake of Hericium erinaceus. Randomised placebo-controlled trial, 31 adults over 50, 12 weeks; funding not stated. Biomedical Research, 2019. PubMed 31413233.
3. Li IC, et al. Erinacine A-enriched mycelia in early Alzheimer's disease. Randomised placebo-controlled pilot, 68 enrolled, 49 weeks; supplier-run. Frontiers in Aging Neuroscience, 2020. PubMed 32581767.
4. Docherty S, et al. Lion's mane, cognition, stress and mood in young adults. Randomised placebo-controlled pilot, 41 adults, 28 days; product supplied by a producer. Nutrients, 2023. PubMed 38004235.
5. La Monica MB, et al. Guayusa tea and lion's mane extracts and cognitive performance. Randomised crossover, single dose; part-funded by the tea extract's supplier. Nutrients, 2023. PubMed 38140277.
6. Grozier CD, et al. Four weeks of Hericium erinaceus and metabolic flexibility or cognition. Single-blind placebo-controlled trial, 24 adults, 4 weeks; funding not stated. International Journal of Exercise Science, 2022. PubMed 36582308.
7. Nagano M, et al. Depression and anxiety after 4 weeks of Hericium erinaceus. Randomised placebo-controlled trial, 30 women, 4 weeks; funding not stated. Biomedical Research, 2010. PubMed 20834180.
8. Vigna L, et al. Hericium erinaceus, mood and sleep in overweight adults. Uncontrolled before-and-after study, 77 adults, 8 weeks. Evidence-Based Complementary and Alternative Medicine, 2019. PubMed 31118969.
9. Menon A, et al. Hericium erinaceus as a supplement. Systematic review, 5 randomised and 3 pilot trials; no commercial funding. Frontiers in Nutrition, 2025. PubMed 40959699.
10. Food Standards Agency. How to report a food safety or hygiene issue for members of the public. gov.uk.
11. NHS. Where to get urgent help for mental health. Reviewed 26 April 2023; read 29 October 2026. nhs.uk.
12. Surendran G, et al. A standardised Hericium erinaceus extract and cognition in healthy younger adults. Randomised placebo-controlled crossover, 18 adults, one 3 g dose; two authors employed by a drinks maker using lion's mane. Frontiers in Nutrition, 2025. PubMed 40276537.

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General information, not medical advice: with a prescribed medicine, a history of anxiety or depression, pregnancy, breastfeeding or cancer treatment, ask a pharmacist, GP or specialist first.