Science · Lion's Mane
Lion's Mane and the Brain: The Scientific Evidence Behind the Mushroom that Stimulates Neuronal Growth
Hericium erinaceus — also known as Lion's Mane — is one of the most studied mushrooms in neuroscience. A comprehensive review published in the International Journal of Molecular Sciences (2023) summarizes decades of research on its neuroprotective and neurotrophic properties, with results that point to real potential in the prevention and support of neurodegenerative diseases.
Key Study Finding
The active compounds in Lion's Mane — erinacines and hericenones — are able to cross the blood-brain barrier and directly stimulate the synthesis of nerve growth factor (NGF) in the brain.
What is NGF and why does it matter?
Nerve growth factor (NGF) is an essential protein for the survival, differentiation, and plasticity of neurons. Without sufficient NGF, cholinergic neurons — responsible for memory and learning — degenerate. It is no coincidence that NGF levels are significantly reduced in Alzheimer's patients.
The problem is that NGF cannot be administered directly as a drug: it does not cross the blood-brain barrier and degrades quickly. Hence the scientific interest in finding natural compounds that stimulate its production from within. Lion's Mane is, to date, the most promising candidate.
Active Compounds
Lion's Mane contains two families of unique compounds with proven neurotrophic activity:
From the mycelium
Erinacines
Diterpenoids that stimulate NGF synthesis and cross the blood-brain barrier. 19 types identified, 10 with proven neuroprotective activity.
From the fruiting body
Hericenones
Phenolic derivatives exclusive to Lion's Mane. Hericenones C, D, E, and H stimulate NGF synthesis. Hericenone E is the most active.
An important fact: erinacine A — one of the most studied compounds — is exclusively present in fermented mycelium, not in the fruiting body. Hericenones, on the other hand, are exclusive to the fruiting body. This explains why the origin of the extract (mycelium vs. fruiting body) significantly changes the activity profile of the supplement.
What the Evidence Says
Alzheimer's
↓ Aβ
Reduction of amyloid plaques in transgenic models after 30 days of supplementation
Memory
+NGF
5x increase in NGF gene expression in the hippocampus after 7 days of oral administration
Clinical Trial
16 wk
Significant improvement in cognitive function in adults with mild cognitive impairment (double-blind)
Depression & Anxiety
↓ 4 wk
Reduction of depression and anxiety symptoms in 30 women after 4 weeks of supplementation
Mechanisms of Action
Lion's Mane acts on the nervous system through several simultaneous mechanisms:
NGF and BDNF Stimulation
Erinacines and hericenones activate the synthesis of the two most important neurotrophins: NGF (memory, learning) and BDNF (synaptic plasticity, mood).
Reduction of Neuroinflammation
Inhibition of NF-κB, reduction of pro-inflammatory cytokines (IL-6, TNF-α, iNOS) and activation of the neuroprotective Nrf2/HO-1 pathway.
Protection against Oxidative Stress
Polysaccharides (beta-glucans), hericenones, and erinacines reduce ROS accumulation and protect neuronal mitochondria from oxidative damage.
Promotion of Neurogenesis
Stimulates the proliferation of progenitor cells in the hippocampus (dentate gyrus), the brain area responsible for forming new memories.
Inhibition of Neuronal Apoptosis
Protection against endoplasmic reticulum stress, one of the key mechanisms of neuronal death in Alzheimer's, Parkinson's, and Huntington's diseases.
Human Clinical Trials
Data in humans is still limited but consistent. The reference clinical trial (Mori et al., 2009) conducted a double-blind, placebo-controlled study in adults aged 50 to 80 with mild cognitive impairment. After 16 weeks of Lion's Mane supplementation, participants showed significant improvements on the Hasegawa dementia scale. The improvements disappeared 4 weeks after stopping the treatment, suggesting that the effect requires continuous supplementation.
Subsequent studies confirmed improvements in short-term memory, reduction of anxiety and depression, and improvements in sleep. A study in patients with mild Alzheimer's showed a reduction in cognitive decline after 49 weeks of supplementation with erinacine A-enriched mycelium extract.
Safety and Toxicology
The review confirms a strong safety profile. Subchronic studies in rats with doses up to 2,000 mg/kg/day for 90 days showed no toxicity, morbidity, or mortality. The no observed adverse effect level (NOAEL) for the beta-glucan extract was established at 2,000 mg/kg/day — the highest dose tested.
Genotoxicity tests (Ames test, in vitro chromosomal aberration test, in vivo micronucleus test) were all negative, confirming the absence of mutagenic effects.
Why the Origin of the Extract Matters
The review highlights a point that many manufacturers overlook: mycelium and fruiting body have distinct compound profiles. Erinacine A — the most studied compound in Alzheimer's models — is only present in fermented mycelium. Hericenones — equally valuable for NGF stimulation — are exclusive to the fruiting body.
A quality supplement should clearly specify the origin (mycelium, fruiting body, or both), standardized compounds (beta-glucans, erinacines, hericenones), and have third-party analyses verifying the product's actual composition.
Available Now
Lion's Mane Grow Kit
Grow your own Hericium erinaceus at home.
Origin Tenerife, Canary Islands.
Scientific Reference
Szućko-Kociuba I, Trzeciak-Ryczek A, Kupnicka P, Chlubek D. (2023). Neurotrophic and Neuroprotective Effects of Hericium erinaceus. International Journal of Molecular Sciences. PMCID: PMC10650066. PMID: 37958943.