Due to the growing popularity of vital mushroom supplementation, the question of their tolerance is increasingly being raised. In which cases should caution be exercised when taking lion's mane? Side effects and adverse reactions after its consumption are relatively rare. Nevertheless, not everyone can take it. Find out who should avoid this mushroom and what body signals to pay attention to during treatment.
How does lion's mane affect the body?
Lion's mane (Hericium erinaceus) acts on the body in multiple ways thanks to the presence of hericenones, erinacines, and β-glucans. It supports nervous system function, reduces oxidative stress, alleviates inflammation, modulates the immune system, and promotes gut microbiota diversity.
It is precisely its multi-directional action that accounts for both the benefits of using lion's mane and the fact that some people may experience adverse reactions. The bioactive compounds in lion's mane can potentially influence, among other things:
-
inflammatory mechanisms,
-
blood clotting,
-
glucose metabolism.
Is lion's mane supplementation safe?
Most people can safely take lion's mane. Side effects from its consumption are rare, and its supplementation is considered safe. This mushroom has no toxic effects and is well-tolerated both in single doses and during long-term treatment.
This is confirmed by the analysis of Mahadevan et al. (2025), which showed no toxicity or genotoxic effects (i.e., damage to the genetic material of cells) – even at doses significantly higher than those typically used in humans.
What are the most common side effects of lion's mane?
Among the most frequently reported side effects of lion's mane supplementation, mild gastrointestinal discomfort and skin reactions dominate. Most of them resolve spontaneously after reducing the dose.
What ailments can appear after taking lion's mane? Side effects listed in the systematic review by Menon et al. (2025) include:
-
stomach discomfort,
-
nausea,
-
headaches,
-
allergic reactions (rash, itchy skin),
-
changes in bowel habits.
When can lion's mane cause adverse reactions?
Adverse reactions to lion's mane most often occur with hypersensitivity to mushrooms, excessively high doses, concomitant use of certain medications, and consumption of the raw fruiting body.
Drug interactions pose a significant risk. Lion's mane should not be combined with:
-
antidiabetic medications,
-
anticoagulants,
-
immunosuppressants.
Are you unsure if your body will tolerate the treatment well? In such a situation, talk to a doctor, especially if you are taking any of the listed types of pharmaceuticals.
Who should avoid or use lion's mane supplementation with caution?
Not everyone can take lion's mane. Its side effects and its impact on the body are dangerous for people with mushroom allergies. Its supplementation is also not recommended for chronically ill individuals, particularly patients with autoimmune diseases, and pregnant women.
Avoid lion's mane if:
-
you have a mushroom allergy,
-
you suffer from an autoimmune disease,
-
you are planning a pregnancy, are pregnant, or breastfeeding,
-
you have a planned surgical procedure.
Can everyone take lion's mane? The side effects resulting from its use are a topic worth exploring before starting supplementation. Lion's mane is one of the best-tolerated vital mushrooms, and the most commonly reported adverse effects are mild. Nevertheless, every decision to include the supplement should be tailored to one's health situation, and in case of doubt, consulted with a specialist.
FAQ – frequently asked questions
-
Can lion's mane cause allergies?
Yes, cases of allergic reactions to lion's mane have been described in scientific literature. People with mushroom allergies should refrain from supplementation.
-
Is lion's mane safe for long-term supplementation?
Lion's mane shows good tolerance, even with prolonged use. However, data from multi-year observations are lacking, so it is advisable to take a short break every few months.
-
Does lion's mane affect blood sugar levels?
Some compounds in lion's mane inhibit α-glucosidase, which can lower postprandial glucose levels. Diabetics taking medication should regularly monitor their blood glucose.
-
Can lion's mane affect blood pressure?
The direct hypotensive effect of lion's mane has not been confirmed in human clinical trials. Nevertheless, individuals taking blood pressure medication should exercise caution and consult a specialist about their treatment.
-
Can lion's mane cause headaches?
Yes, headaches are considered a potential, though rarely reported, side effect of lion's mane. They are usually mild and resolve after lowering the dose or a short break in supplementation.
Sources:
-
Menon, A., Jalal, A., Arshad, Z., Nawaz, F., & Kashyap, R. (2025). Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Frontiers in Nutrition, 12. https://doi.org/10.3389/fnut.2025.1641246.
-
Mahadevan, K., Daoust, J., Brendler, T., Chaudhary, A., Saifi, A., & Garg, V. (2025). A toxicological assessment of Hericium erinaceus (Lion’s mane) and Trametes versicolor (Turkey tail) mushroom powders. Frontiers in Toxicology, 7. https://doi.org/10.3389/ftox.2025.1651442.
-
Komoń, A., Romańczuk, K., Kamińska-Omasta, K., Wójtowicz, J., Ujazda, D., Bodziony, K., Tyniec, M., & Morshed, K. (2024). Neuroprotective and Cognitive Benefits of Hericium erinaceus: A Comprehensive Review of Recent Clinical Studies. Biuletyn Głównej Biblioteki Lekarskiej, 57, 279 - 290. https://doi.org/10.2478/bgbl-2024-0038.
-
Lee, S., Ryu, S., Turk, A., Yeon, S., Jo, Y., Han, Y., Hwang, B., Lee, K., & Lee, M. (2020). Characterization of α-glucosidase inhibitory constituents of the fruiting body of lion's mane mushroom (Hericium erinaceus).. Journal of ethnopharmacology, 113197 . https://doi.org/10.1016/j.jep.2020.113197.
-
Contato, A., & Conte‐Junior, C. (2025). Lion’s Mane Mushroom (Hericium erinaceus): A Neuroprotective Fungus with Antioxidant, Anti-Inflammatory, and Antimicrobial Potential—A Narrative Review. Nutrients, 17. https://doi.org/10.3390/nu17081307.
Leave a comment: