Guide
Who should not take lion's mane?
People with a mushroom allergy should not take lion's mane. Our label also says to ask a physician first if pregnant or nursing, under 18, on medication or with a medical condition.
Anyone with a mushroom allergy should not take lion's mane, and our label says so. Our label also says to ask a physician first if you are pregnant or nursing, under 18, taking medication or have a medical condition. Those are cautions from the label, not findings from a study of those groups.
The groups to be careful with
- Mushroom allergy. Do not use it. A 2025 systematic review lists allergic reactions among possible side effects (PMID 40959699).
- Pregnant or nursing. Ask a physician first. We found no safety data for lion's mane in pregnancy or breastfeeding and give no use guidance.
- Under 18. Ask a physician first. We give no use guidance for children.
- Anyone taking medication. Ask first. We found no human interaction trials, so the question cannot be answered from research; see lion's mane and medications.
- Anyone with a medical condition, including kidney or liver problems. We found no studies in these groups, so there is no evidence either way. Your doctor knows your history; we do not.
- Before surgery. If you are scheduled for surgery, tell your surgeon about every supplement. In lab work, a compound from lion's mane reduced collagen-triggered platelet clumping in rabbit and human platelets (PMID 20637576). That does not show an effect in people, but it is the reason to mention it.
Our label
Lion's Mane Mushroom: 1,000 mg of organic lion's mane fruiting body and mycelium powder per two capsules, as low as $18.23 a bottle on subscription. The label warns: do not use if allergic to mushrooms; ask a physician before use if pregnant or nursing, under 18, on medication or with a medical condition.
Questions people ask
Who should not take lion's mane?
People with a mushroom allergy. People in the groups above should talk to a physician before trying it.
Is lion's mane safe if I have kidney or other organ problems?
We found no human study of lion's mane in people with kidney problems, either for or against it, and we make no claim about kidney health. Ask your doctor. A 2016 study in rats given an aqueous fruiting-body extract found no adverse effect on body weight, blood tests or organ weights at up to 1,000 mg/kg for 90 days (PMID 27816657), but rat results do not establish safety for people with kidney problems.
What if lion's mane is not working?
The honest answer is that nobody has shown what it should do at capsule doses, so "not working" has no agreed measure. The trials ran from single doses to 49 weeks. If you do not notice a difference, you are in line with some of the null trials in lion's mane benefits: what the research does and doesn't show. If you have a symptom that worries you, see a doctor instead of increasing the dose.
Sources
- Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review A 2025 review of lion's mane studies listed stomach discomfort, headache and allergic reactions as possible side effects and noted they are commonly unreported.
- Inhibitory effect of hericenone B from Hericium erinaceus on collagen-induced platelet aggregation In the lab, a compound from lion's mane reduced collagen-triggered platelet clumping in rabbit and human platelets.
- Haematological, biochemical and histopathological aspects of Hericium erinaceus ingestion in a rodent model: A sub-chronic toxicological assessment Rats given a lion's mane fruiting-body extract for 90 days at up to 1,000 mg/kg showed no adverse effects on weight, blood tests or organ weights.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
