lion's mane

Lion's Mane (Hericium erinaceus) is an edible mushroom found across North America, Europe, and Asia. It has long been eaten as food and used in traditional Chinese herbalism, sometimes described as a "tonic." It contains compounds known as hericenones and erinacines that have attracted scientific interest, and it is sold over the counter as a dietary supplement in the form of powders, capsules, and extracts.

Rigorous evidence in people is limited, and there is no NIH Office of Dietary Supplements or NCCIH consumer fact sheet for Lion's Mane. The NIH/NLM LiverTox monograph describes the idea that it improves cognition or relieves anxiety and depression as "purported," and states that most of these effects "have been demonstrated in cell culture or in animal models but have not been found in humans." It adds that neuroprotective and cognitive-enhancing activities "have not been shown to any great extent in humans." Human studies so far have been small and preliminary, and Lion's Mane is not an established treatment for any disease.

There is no established or standardized dose, and Lion's Mane is not approved by the FDA to treat any condition. Marketed products vary widely in form and strength, and the limited human studies have used a broad range of amounts, so no single dose can be recommended. Because quality varies and the supplement is not regulated like a medicine, talk to a clinician before starting Lion's Mane, especially if you are pregnant, nursing, or managing a health condition.

Lion's Mane has a long history of use as a food and is generally regarded as well tolerated. The NIH/NLM LiverTox resource classifies it as an unlikely cause of clinically apparent liver injury and notes that no such cases have been reported in connection with it. People with mushroom allergies should be cautious, because at least one acute hypersensitivity (allergic) reaction to oral Lion's Mane has been described. Long-term safety, and use during pregnancy or breastfeeding, have not been well studied, so check with a clinician first.

Reported side effects are generally mild and uncommon. The NIH/NLM LiverTox monograph notes that mild stomach-related complaints — such as abdominal discomfort, nausea, or diarrhea — have turned up in studies, typically in under one in ten participants. A single acute hypersensitivity (allergic) reaction has also been reported.

No specific drug interactions are documented in the cited NIH/NLM source. Even so, because the evidence base is thin and dietary supplements can interact with medicines, let your clinician or pharmacist know you are taking Lion's Mane before combining it with any prescription drugs.