Lion's Mane Dosage & Side Effects
The clinical trial with the clearest published cognitive results used 3 g/day for 16 weeks in adults with mild cognitive impairment; reported side effects were mild and gastrointestinal or skin-related, with no documented liver injury at typical doses.
Doses used in published research
The most-cited human trial on Lion's Mane dosed adults age 50 to 80 with mild cognitive impairment at four 250 mg tablets of 96% Yamabushitake dry powder, three times a day, roughly 3 g/day total, for 16 weeks, per Mori et al., 2009, Phytotherapy Research. A separate pilot study in healthy adults 18 to 45 tested Lion's Mane over a shorter 4-week period, per PMC10675414, 2023, though that study doesn't publish the same level of dose detail as the 2009 trial.
| Study | Population | Dose | Duration |
|---|---|---|---|
| Mori et al., 2009, Phytotherapy Research | Adults 50-80 with mild cognitive impairment (n=30) | 3 g/day (four 250 mg tablets, 96% Yamabushitake dry powder, three times daily) | 16 weeks, plus a 4-week washout period |
| PMC10675414, 2023 | Healthy adults 18-45 | Not specified in the same detail; smaller pilot dose over a shorter period | 4 weeks |
A limitation worth naming plainly: the 2009 trial had 30 total participants, 15 per group, and the cognitive improvement seen during treatment reversed after a 4-week washout once subjects stopped taking it, meaning the measured benefit required continued use at that dose.
Reported side effects
Per Memorial Sloan Kettering Cancer Center's clinical summary, abdominal discomfort, nausea, and skin rash were reported in a clinical study of Lion's Mane. Skin reactions have also been documented in case reports as itching or rash that resolved after discontinuing use, most relevant to anyone with a known mushroom allergy. Per the NCBI Bookshelf LiverTox review, there are no reported cases of liver injury attributed to Lion's Mane at typical oral doses in the available clinical literature.
This page doesn't evaluate how any specific supplement product's label dose compares to these study doses; see the Lion's Mane Supplement Guide for a label-by-label breakdown of what two named brands disclose.
Frequently Asked Questions
Sources
- Mori et al., 2009, Phytotherapy Research: Double-blind, placebo-controlled trial: 3 g/day Yamabushitake dry powder for 16 weeks in adults 50-80 with mild cognitive impairment (n=30), plus a 4-week washout
- PMC10675414, 2023: Double-blind pilot study of Lion's Mane on cognition, stress, and mood in healthy adults 18-45 over 4 weeks
- Memorial Sloan Kettering Cancer Center, Lion's Mane Mushroom clinical summary: Reported adverse effects (abdominal discomfort, nausea, skin rash) documented in clinical study
- NCBI Bookshelf, LiverTox: Lion's Mane: Clinical safety review of Lion's Mane supplementation