Lion's mane (Hericium erinaceus) is a white, globe-shaped mushroom that grows on dead hardwood trees like oak. It's part of the tooth fungus family and is large and shaggy in appearance. Lion's mane is used in East Asian medicine for both culinary and medicinal purposes.

Lion's mane contains bioactive substances that may have many beneficial effects on the body, especially the brain, heart, and gut. It may improve nerve development and function, and protect nerves from becoming damaged. Lion's mane also contains compounds that support healthy nerve growth and inflammatory responses for the brain, immune, and gastrointestinal systems.

Lion's mane is composed of two parts: the visible fruiting body (the mushroom) and the mycelium, which is the bottom structure that resembles roots. Both the fruiting body and the root-like mycelium contain compounds that offer potential health benefits.