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 the 50 forum threads we 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. This page says what people report, what the trials measured, and what to do if you feel unwell; it is a spoke of the Wellgard guide do mushroom supplements work?, and lion's mane side effects covers safety in full.

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", and the line one long-term user chose, "I didn't become Einstein". The "nothing" reports are as common: "nada, zilch, nothing" 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 Nobody in that trial was asked how they felt. Lion's mane is not a psychedelic and contains no psilocybin; does lion's mane get you high deals with that question.

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

This has become the most searched lion's mane question, and today forum threads answer it. What those 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). Most posters disclose something else going on: an anxiety or depressive disorder, antidepressants, stimulants, antihistamines, recreational drugs, a four-supplement stack, or a sublingual or doubled dose. 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 8 October 2026.^{3, 6, 9} So the reports are real as reports and undocumented as effects. If you feel weird, stop taking it; most early reactions settle. See a pharmacist or GP, or call NHS 111, if it does not, and report it through the MHRA Yellow Card scheme.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 three in healthy young adults. In the impaired group: the 30-person, 16-week trial above; a 12-week trial 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; and 10 g a day in muffins for four weeks changed nothing in 24 adults.^{4, 5, 6} The systematic review that pooled what it could found a 1.17-point MMSE gain, in trials it called small and unreplicated.⁹ So the plain reading for a 45-year-old with "meno brain" or a 30-year-old who cannot focus at work is: the people studied were not you, the effect in the best trial was on a test score and reversed on stopping, and "nootropic" is a marketing word rather than a measured outcome.

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 That is the whole menopause literature. On the UK menopause forums, lion's mane comes up as an aside in a brain-fog conversation whose better-supported answers are HRT options, 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 who cannot have HRT because she is on letrozole, anastrozole or tamoxifen after breast cancer. 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 the step before any tub is a conversation with the oncology pharmacist; 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 and one trend. 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, but with no control group, so the diet, the attention and the mushroom cannot be told apart; and the 41-adult trial's lower subjective stress at 28 days, p = 0.051.^{4, 7, 8} That is not evidence that lion's mane reduces anxiety or depression, and it is not an antidepressant: nothing here should change how anyone takes a prescribed one. 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, and the cookie trial's own authors doubted NGF explained their result.^{7, 9} Cortisol, which readers ask about in five different ways, has not been measured in any human lion's mane trial we found; the trials that touched stress used questionnaires.⁴

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

None of these has been measured. 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: some people describe feeling more awake, a few say it makes them drowsy or keeps them up, and four posters in our sample described vivid dreams or "dreaming again", usually welcomed, once listed as a symptom. The only sleep data are the uncontrolled 77-adult study, where sleep scores improved alongside everything else, and nobody has measured REM sleep.⁸ If it noticeably changes your sleep in either direction, the fix is timing, below, or stopping.

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

Untested: 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} So the practical answer follows your own response. Take it with breakfast as the default; if it seems to keep you awake, keep it to the morning; if it seems to make you drowsy, move it to the evening. "Can I take lion's mane at night" is therefore yes, if that suits you.

Frequently asked questions

Can you feel lion's mane working, and how long does it take?

Most people feel nothing; those who report a change say day two or three, while the one positive trial first measured a difference at week 8 and the effect was gone four weeks after stopping.¹

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, and see the safety page.

Does lion's mane affect cortisol?

No human trial has measured cortisol; claims that it raises or lowers it come from laboratory and animal work.

Is lion's mane an antidepressant?

No. Two small studies, one uncontrolled, and a non-significant stress trend are the evidence; it is a food, not a medicine, and never a substitute for one.^{4, 7, 8}

Does lion's mane make you hungry?

Appetite has not been measured in any trial; the one study in people with binge-eating problems had no control group.⁸

Sources

1. 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 18844328.
2. Saitsu Y, et al. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomedical Research, 2019. PubMed 31413233.
3. 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 32581767.
4. Docherty S, et al. The acute and chronic effects of lion's mane mushroom supplementation on cognitive function, stress and mood in young adults: a double-blind, parallel groups, pilot study. Nutrients, 2023. PubMed 38004235.
5. La Monica MB, et al. Acute effects of naturally occurring guayusa tea and Nordic lion's mane extracts on cognitive performance. Nutrients, 2023. PubMed 38140277.
6. Grozier CD, et al. Four weeks of Hericium erinaceus supplementation does not impact markers of metabolic flexibility or cognition. International Journal of Exercise Science, 2022. PubMed 36582308.
7. Nagano M, et al. Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake. Biomedical Research, 2010. PubMed 20834180.
8. Vigna L, et al. Hericium erinaceus improves mood and sleep disorders in patients affected by overweight or obesity: could circulating pro-BDNF and BDNF be potential biomarkers? Evidence-Based Complementary and Alternative Medicine, 2019. PubMed 31118969.
9. Menon A, et al. Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Frontiers in Nutrition, 2025. PubMed 40959699.
10. MHRA. Yellow Card: report a suspected side effect. yellowcard.mhra.gov.uk.
11. NHS. Where to get urgent help for mental health. nhs.uk/nhs-services/mental-health-services/where-to-get-urgent-help-for-mental-health.

General information, not medical advice. If you take a prescribed medicine, have a history of anxiety or depression, are pregnant or breastfeeding, or are on cancer treatment, ask your pharmacist, GP or specialist before starting lion's mane, and never change a prescribed medicine on the strength of a supplement.