Hericium erinaceus — Lion's Mane mushroom — has a long history in Traditional Chinese and Japanese medicine, where it was used to support digestive health and fortify the mind. Modern neuroscience has given that tradition a molecular explanation that has turned the supplement industry's attention squarely toward this shaggy white mushroom.
The Active Compounds: Hericenones and Erinacines
Lion's Mane contains two classes of compounds with neuroactive properties found nowhere else in nature. Hericenones are found primarily in the fruiting body (the mushroom itself); erinacines are found primarily in the mycelium (the root-like network). Both have been shown to cross the blood-brain barrier and stimulate the synthesis of Nerve Growth Factor (NGF) — a protein essential for the growth, maintenance, and survival of neurons.
Nerve Growth Factor: Why It Matters
NGF was discovered by Nobel laureate Rita Levi-Montalcini in the 1950s. It plays a critical role in the development and survival of neurons in the peripheral and central nervous system, supports the maintenance of cholinergic neurons (which decline significantly in Alzheimer's disease), and promotes neuroplasticity — the brain's ability to form new connections.
The challenge has been that NGF itself cannot easily cross the blood-brain barrier, making it difficult to administer therapeutically. Compounds that stimulate the brain's own NGF production — from within — represent a fundamentally different and more practical approach. Lion's Mane hericenones and erinacines do exactly this.
Clinical Evidence
Mild Cognitive Impairment
The landmark human clinical trial for Lion's Mane was published in Phytotherapy Research in 2009 by Mori et al. The double-blind, placebo-controlled study enrolled 30 Japanese adults aged 50–80 with mild cognitive impairment. The treatment group received 750mg of H. erinaceus fruiting body powder three times daily for 16 weeks. Cognitive function scores improved significantly compared to placebo — and notably, the improvements reversed when supplementation was stopped, suggesting an ongoing mechanistic effect rather than a one-time benefit.
Anxiety and Depression
A 2010 study in Biomedical Research found that Lion's Mane supplementation significantly reduced depression and anxiety scores in a cohort of menopausal women. The mechanism is likely related to NGF's role in the maintenance of serotonergic and cholinergic neuronal populations, as well as the compound's anti-inflammatory effects in the brain.
Peripheral Nerve Repair
Erinacines have demonstrated the ability to accelerate peripheral nerve regeneration in animal models — with implications for conditions like peripheral neuropathy, post-surgical nerve damage, and diabetic neuropathy. This is one of the more remarkable properties in the Lion's Mane research portfolio.
My neurologist told me there wasn't much I could do proactively to slow the cognitive decline my family history puts me at risk for. I started Lion's Mane after reading the Mori study. Three months in, my memory and word retrieval are noticeably better — and my partner has commented without me asking. — Lion's Mane consumer, 61, Boston
Fruiting Body vs. Mycelium: The Formulation Decision That Matters
This distinction is critical for practitioners and brands. The erinacines are concentrated in the mycelium; hericenones in the fruiting body. Most commercial Lion's Mane products are mycelium grown on grain substrate — which means the final product contains significant starch from the grain, not just fungal matter. Fruiting body extracts standardized to beta-glucan content are generally considered the higher-quality standard and more closely match what was used in clinical trials.
When evaluating Lion's Mane products, look for: fruiting body source (or a specified mycelium extraction process that removes grain), beta-glucan content verification by third-party testing, and organic certification to ensure absence of pesticides and heavy metals.