The #1 Lion's Mane Superfood


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Lion’s Mane Side Effects

People swear by lion’s mane mushrooms for their ability to improve overall cognitive function, while others use them as complementary medicine in their fight against cancer, diabetes, or multiple sclerosis.

Are there any side effects to taking lion’s mane? We read through the latest studies on the potential dangers of lion's mane so you don't have to.

Spoiler alert—lion’s mane is safe with few contraindications.

Article jumplinks:

What are the side effects of taking lion's mane?

What are the lion's mane mushroom benefits?

How much lion’s mane is in Forij granola?

Centuries of Hericium erinaceus use in traditional Chinese medicine and research by qualified health care professionals suggest that lion’s mane mushrooms are not addictive and are completely safe to consume.


Lion’s Mane Risks and Side Effects

When taking lion’s mane, there is always a remote possibility of adverse effects such as an upset stomach, diarrhea, abdominal discomfort, nausea, and mild skin rashes, but these occur rarely and at high dosages. In order to avoid these side effects, start with a lower dose of the mushroom and work your way up.

Lion’s Mane Drug Interactions

Although there is sparse research on lion’s mane drug interactions, the mushroom may have certain effects that may interfere with medications for medical conditions such as diabetes or blood clotting.

For one, lion’s mane seems to have antiplatelet effects. According to a study, “hericenone B had a strong anti-platelet activity and it might be a novel compound for antithrombotic therapy possessing a novel mechanism.”

If you’re already on blood thinners, you may want to consult with a medical professional about a potential interaction in order to avoid symptoms such as prolonged wound healing and bruising.

Similarly, an animal study on the effects of lion’s mane on diabetic mice suggests that this medicinal mushroom has antihyperglycemic effects, meaning that it lowers blood sugar levels. Therefore, if you’re already on antidiabetics, you should keep track of your blood sugar levels when taking lion’s mane to make sure it doesn’t dip below normal levels.

To learn more about medications that may interact with Hericium erinaceus, take a look at our guide to lion’s mane drug interactions.Lion's mane allergic reaction

Lion’s Mane Allergic Reactions

The chances of having an allergic reaction to lion’s mane are slim. However, if you are prone to allergies or have experienced allergic reactions to fungi or yeast before, lion’s mane could be contraindicated for you. If you notice any signs of an allergic reaction, stop taking the mushroom immediately and contact a medical professional.

Lion’s Mane Use During Pregnancy

There is no evidence that lion’s mane has an adverse effect on fetal development. Centuries of use suggest that it’s fine for pregnancy and newborns. However, since there are no studies on the safety of this mushroom during pregnancy, you might err on the side of caution and consult your physician if trying for a baby.

We go further in depth on this topic in our article on taking lion’s mane during pregnancy. And, if you want to learn about the mushroom’s safety while breastfeeding, take a look at our blog post on lion’s mane and breastfeeding.

Potential Health Benefits of Lion’s Mane Mushrooms

Lion’s mane mushrooms have a plethora of potential benefits, as they seem to have protective effects on the whole body and improve overall immune function. Many use these medicinal mushrooms for weight loss and weight management, while others praise them for their antioxidant activity.

To learn more about how this amazing mushroom can improve your physical and mental wellbeing, read our guide to lion’s mane health benefits.

Protection Against Cancer

A few studies suggest that lion’s mane mushrooms seem to cause apoptosis (the process of programmed cell death) of cancer cells, and protect against various types of cancer, including leukemiabreast cancer, and gastric cancer.

Cerebrosides, compounds found in the fruiting bodies of Hericium erinaceus, show promising therapeutic potential in cancer treatment. Cerebroside E, in particular, seems to aid in cancer treatment, according to an in vitro study. The results of this study “collectively reflect the beneficial effects of [Hericium erinaceus] in cancer treatment.”

Neurological Health Benefits

Lion’s mane shows potential in overall brain health protection and maintenance. For one, these nootropic mushrooms seem to preserve cognitive function in people with Alzheimer’s disease and may slow down the progression of the illness.

Chemical constituents found in Hericium erinaceus aid in neurite outgrowth, according to a 2015 study. The mushroom’s ability to promote nerve growth seems to be the main mechanism behind its neurological health properties, such as mild cognitive impairment prevention and overall nervous system protection.

placebo-controlled human study examined the effects of Hericium erinaceus on mild cognitive impairment. This study concluded that “at weeks 8, 12 and 16 of the trial, the [Hericium erinaceus] group showed significantly increased scores on the cognitive function scale compared with the placebo group.”

Additionally, lion’s mane aqueous extracts show potential in Parkinson’s disease treatment due to the mushroom’s neurotrophic properties.

We do a deep dive into the neurological benefits of lion’s mane in our article on Hericium erinaceus and neurogenesis. Check it out!

Heart Health Benefits

According to the CDC, heart disease is the leading cause of death in the United States, with coronary artery disease and heart attacks being the most prevalent.

Healthcare professionals stress proper nutrition and supplement use as a number one way to prevent heart problems, and studies published on the effect of Hericium erinaceus on heart health suggest that the fungus could be a great addition to a health-conscious diet. According to a recent study, “Administration of Hericium erinaceus ethanol extract…resulted in a significant decrease in body weight gain, fat weight, and serum and hepatic triacylglycerol levels.”

Additionally, a 2010 study found that a compound found in this mushroom seems to lessen platelet aggregation, a mechanism behind the formation of blood clots. Therefore, lion’s mane extracts could be useful for blood clot prevention in people susceptible to thrombosis.

Mental Health Benefits

In addition to cognitive health, Hericium erinaceus seems to aid in depression and anxiety relief and overall mental clarity. A double-blind, placebo-controlled study examined the effects of the lion’s mane mushroom on various menopause symptoms, including anxiety and depression.

The participants that consumed lion’s mane for 4 weeks scored lower on tests that measure symptoms of depressive disorders and anxiety than the control group, meaning they exhibited fewer signs of these conditions.

Read our article on taking lion’s mane for depression, as well as on lion’s mane and anxiety, to learn more about the mental health potential of these mushrooms.

Interested in Trying Lion’s Mane?

Lion’s mane is generally safe for most people. Still, if you want to take this adaptogenic mushroom and are concerned about possible side effects, it’s best to consult with a medical professional before you start taking a supplement.

Forij Superfood Granola

Once your doctor gives you the green light, incorporate the helpful mushroom into your diet with our mushroom granola.

The granola is vegan, gluten-free, packed with nutrients, and delicious. What more could you want in a morning bowl of cereal?

Lion’s Mane Side Effects FAQ

How much lion’s mane is in Forij granola?

Forij granola uses a high-quality lion's mane extract made from whole adaptogenic mushrooms. Our dual extraction method extracts both water-soluble beta-glucans as well as alcohol-soluble triterpenes. Our decoction process breaks down indigestible chitin cell walls of the mushroom to get much more of these compounds out than ordinary processes do.

One serving of our granola provides 250 mg of hyperconcentrated lion's mane extract, which is eight times more concentrated than a regular lion’s mane supplement. Therefore, you get as much lion's mane potency as you would if you were taking a 2000 mg mushroom powder supplement, all in one bowl of granola.

Does lion’s mane help with sleep disorders?

Evidence based research suggests that lion’s mane supplements may improve sleep quality, especially in sleep disorders related to acute stress.

clinical trial looked at the effects of lion’s mane on insomnia caused by exam-related stress in Japanese students. Compared to the control group, students who took the mushroom supplement reported feeling less anxious and having fewer sleepless nights after 4 weeks.

To learn more about these benefits, read our article on the sleep benefits of lion’s mane mushrooms.

Can lion’s mane cause stomach ulcers?

No, the lion’s mane mushroom does not cause stomach ulcers. Quite the contrary, these medicinal mushrooms seem to improve digestive health and have gastroprotective properties, and they may even protect against ulcers, according to an animal study.

To learn more about the beneficial effect of Hericium erinaceus on gut health, read our post on the taking lion’s mane for digestion.

How long does it take for lion’s mane to work?

If you take lion’s mane dietary supplements every day, you should start noticing some changes in two to three weeks. However, don’t get discouraged if you don’t see an immediate improvement in your symptoms and overall health.

Keep taking daily supplements of the medicinal mushroom, and maybe even increase the amount you consume daily, and you’ll surely notice the benefits of lion’s mane in a month or so.

Can I take lion’s mane and reishi together?

Yes, you can take a lion’s mane mushroom extract with any other type of medicinal fungus or herbal medicine, including reishi mushroom varieties. When it comes to adaptogenic mushrooms, the whole is always greater than the sum of its parts, so the benefits of reishi mushrooms can only be improved upon by taking them with lion’s make and vice versa.

Is lion’s mane good for inflammation and oxidation?

Yes, according to medical reviewers, as well as alternative medicine practitioners, lion’s mane reduces inflammation and oxidative stress in the body.

2022 study examined the antiinflammatory potential of lion’s mane mushroom extracts and found that two Hericium erinaceus compounds “showed moderate inhibitory effects indicating their potential anti-inflammatory activity.”

To learn more about this benefit, take a look at our article on the antiinflammatory potential of Hericium erinaceus.


  1. Mori, K. (2010). Inhibitory effect of hericenone B from Hericium erinaceus on collagen-induced platelet aggregation. Phytomedicine, 17(14), 1082–1085.
  2. Liang, B. (2013). Antihyperglycemic and antihyperlipidemic activities of aqueous extract of Hericium erinaceus in experimental diabetic rats. BMC Complementary and Alternative Medicines, 13(1).
  3. Kim, S. P. (2011). Mechanism of Hericium erinaceus (Yamabushitake) mushroom-induced apoptosis of U937 human monocytic leukemia cells. Food & Function, 2(6), 348.
  4. Atay, S. (2021). Transcriptome-Wide Analysis Reveals the Molecular Mechanism of Tumoricidal Effects of Lion’s Mane Medicinal Mushroom, Hericium erinaceus (Agaricomycetes), on MCF-7 Breast Cancer Cells. International Journal of Medicinal Mushrooms, 23(1), 91–106.
  5. Wang, M. (2017). A Polysaccharide Isolated from Mycelia of the Lion’s Mane Medicinal Mushroom Hericium erinaceus (Agaricomycetes) Induced Apoptosis in Precancerous Human Gastric Cells. International Journal of Medicinal Mushrooms, 19(12), 1053–1060.
  6. Lee, S. R. (2015). A new cerebroside from the fruiting bodies of Hericium erinaceus and its applicability to cancer treatment. Bioorganic & Medicinal Chemistry Letters, 25(24), 5712–5715.
  7. Zhang, C. C. (2015). Chemical constituents from Hericium erinaceus and their ability to stimulate NGF-mediated neurite outgrowth on PC12 cells. Bioorganic & Medicinal Chemistry Letters, 25(22), 5078–5082.
  8. Mori, K. (2009). Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother. Res., 23(3), 367–372.
  9. Hiwatachi, K. (2010). Yamabushitake Mushroom (Hericium erinaceus) Improved Lipid Metabolism in Mice Fed a High-Fat Diet. Bioscience, Biotechnology, and Biochemistry, 74(7), 1447–1451.
  10. Nagano, M. (2010). Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake. Biomed. Res., 31(4), 231–237.
  11. Okamura, H. (2015). The effects of Hericium erinaceus (Amyloban® 3399) on sleep quality and subjective well-being among female undergraduate students: A pilot study. Personalized Medicine Universe, 4, 76–78.
  12. Wong, J. Y. (2013). Gastroprotective Effects of Lion’s Mane Mushroom Hericium erinaceus (Bull.:Fr.) Pers. (Aphyllophoromycetideae) Extract against Ethanol-Induced Ulcer in Rats. Evid. Based Complement. Alternat. Med., 2013, 1–9.
  13. Xie, G. (2022). Secondary Metabolites from Hericium erinaceus and Their Anti-Inflammatory Activities. Molecules, 27(7), 2157.

Forij Disclaimer

This article was written strictly for informational purposes and this website is not intended to inform about professional medical advice, diagnosis, or treatment of any kind. The statements contained herein have not been evaluated by the Food and Drug Administration (FDA).

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