Lion’s mane mushroom (Hericium erinaceus) has gained attention for its potential benefits, particularly in areas relevant to midlife and menopause. As with any supplement, understanding potential side effects is an important part of informed decision-making.
This article aims to provide an evidence-based overview of reported lion’s mane side effects, specifically for perimenopausal women considering its use. Our focus is on providing balanced, non-hyped information based on available research.
Understanding the Current Evidence on Lion’s Mane Side Effects
The body of research on lion’s mane is growing, but specific studies focusing on its side effects in perimenopausal women are limited. Much of the available information on side effects comes from broader systematic reviews or individual case reports, rather than large-scale clinical trials specifically designed to assess adverse reactions in this demographic [1].
A systematic review from 2025 indicated that Hericium erinaceus is generally considered safe for consumption [1]. However, ‘generally safe’ does not mean ‘free of any potential reactions,’ and individual responses can vary. It’s important to approach supplementation with an awareness of possible, though uncommon, reactions.
Commonly Reported Side Effects: What the Research Suggests
While lion’s mane is often well-tolerated, some individuals have reported mild gastrointestinal discomfort, such as stomach upset or diarrhea, particularly when first starting supplementation or at higher doses. However, these reports are not consistently detailed in clinical trials. For instance, a double-blind, placebo-controlled clinical trial investigating the effects of lion’s mane on mild cognitive impairment did not specifically detail a high incidence of adverse gastrointestinal events, suggesting that if they occurred, they were likely mild and infrequent [2].
Another potential, though less common, reaction could involve allergic responses. As a fungal product, individuals with known mushroom allergies should exercise caution. While specific allergic reactions to lion’s mane are not widely documented in the research cited here, it is a general principle for any natural product [1]. Symptoms of an allergic reaction could include skin rashes, itching, or, in rare cases, more severe reactions.
Less Common or Isolated Side Effects: Insights from Case Reports
While rare, some case reports suggest more significant reactions. One case report from 2025 described Grade 3 cytolysis in a patient with metastatic colorectal cancer who was consuming a mushroom powder-based alternative therapy [3]. It is crucial to note that this was a specific case in a patient with a serious pre-existing condition, consuming a ‘mushroom powder-based alternative therapy’ which may or may not have been exclusively lion’s mane, and the direct causality to lion’s mane alone is not definitively established in this single report. This highlights the importance of discussing all supplements with a healthcare provider, especially if you have existing health conditions or are undergoing medical treatments.
Systematic reviews that broadly examine fungal supplementation on various health markers, such as endurance or immune function in athletes, generally do not highlight a widespread pattern of severe adverse events [4]. This suggests that significant side effects may be uncommon in the general population using these supplements.
Considerations for Perimenopausal Women
Perimenopause is a time of hormonal fluctuation and physiological changes, which can sometimes alter how the body responds to foods, medications, and supplements. While there is no specific evidence indicating that perimenopausal women are more susceptible to lion’s mane side effects compared to other populations, individual sensitivity can vary.
It is always prudent for women in perimenopause to start with a lower dose of any new supplement and monitor their body’s response carefully. Keeping a symptom diary can be helpful in identifying any potential reactions and discussing them with a healthcare professional.
Interactions with Medications and Other Supplements
The potential for lion’s mane to interact with medications is an important consideration. While direct evidence of specific interactions is limited in the research cited here, some mushrooms contain compounds that could theoretically influence various physiological pathways [5]. For example, some bioactives of lion’s mane have been investigated for their potential to target the PPAR signaling pathway [5]. If you are taking prescription medications, particularly those that affect blood clotting, blood sugar, or immune function, it is essential to consult with your doctor or pharmacist before introducing lion’s mane.
The systematic review on Hericium erinaceus as a supplement generally highlights its safety but also underscores the need for caution regarding potential interactions, particularly in individuals with pre-existing health conditions [1]. Always inform your healthcare provider about all supplements you are taking.
References
- Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Frontiers in nutrition, 2025
- Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytotherapy research : PTR, 2009
- Grade 3 cytolysis in a patient with metastatic colorectal cancer consuming a mushroom powder-based alternative therapy. Journal of oncology pharmacy practice : official publication of the International Society of Oncology Pharmacy Practitioners, 2025
- Effects of fungal supplementation on endurance, immune function, and hematological profiles in adult athletes: a systematic review and meta-analysis. Frontiers in nutrition, 2025
- Bioactives of Lion’s Mane Medicinal Mushroom Hericium erinaceus (Agaricomycetes) Targeting PPAR Signaling Pathway: An Experimental and In Silico Investigation. International journal of medicinal mushrooms, 2026
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.