Lion's Mane (Hericium erinaceus) is unlike any other mushroom in nature — a cascading white pom-pom of icicle-like spines that looks nothing like a typical mushroom and even less like anything you would find in a supermarket. It grows on dead hardwood trees across East Asia, North America, and increasingly in commercial cultivation facilities in Ireland. In traditional Chinese and Japanese medicine it has been used for thousands of years to support digestive health and mental clarity. What makes it uniquely interesting to modern neuroscience is that it contains compounds — hericenones and erinacines — that stimulate the production of Nerve Growth Factor (NGF) in the brain.
NGF is not a minor compound. It is essential for the growth, maintenance, and survival of neurons, particularly cholinergic neurons in the hippocampus and basal forebrain — areas critical for memory and learning. NGF also promotes myelination, the formation of the fatty sheath that enables fast neuronal signalling. A substance that reliably increases NGF synthesis is, from a neuroprotection standpoint, extremely interesting.
There are two distinct families of NGF-stimulating compounds in Lion's Mane, and they come from different parts of the mushroom:
This distinction has practical implications when buying supplements: products made from fruiting body only, mycelium only, or both will have different active compound profiles. A high-quality Lion's Mane supplement should ideally contain both fruiting body and mycelium, and should be tested for hericenone content.
The research base on Lion's Mane in humans is smaller than for ashwagandha but growing rapidly. The landmark study is a 2009 double-blind, placebo-controlled trial published in Phytotherapy Research, which followed 30 Japanese adults aged 50–80 with mild cognitive impairment over 16 weeks. Those taking 750mg of dried Lion's Mane fruiting body three times daily (total 2,250mg/day) showed significant improvement on the Hasegawa Dementia Scale compared to placebo. Crucially, the cognitive scores declined again when supplementation stopped — suggesting an ongoing requirement and a real effect, not a placebo response.
A 2019 study in Journal of Alzheimer's Disease found that Lion's Mane extract promoted hippocampal neurogenesis and improved spatial memory in mouse models. A 2020 clinical trial in the International Journal of Medicinal Mushrooms found that 8 weeks of Lion's Mane supplementation significantly improved self-reported concentration and attention in healthy adults aged 18–45.
A 2023 randomised trial published in Nutrients showed that 1.8g/day of Lion's Mane for 28 days produced significant improvements in cognitive processing speed and episodic memory in healthy young adults — one of the first high-quality trials in younger populations.
Beyond raw cognitive performance, Lion's Mane has been studied for its effects on mood. A 2010 Japanese study found that menopausal women who consumed Lion's Mane-containing cookies for four weeks reported significantly lower scores on measures of anxiety, irritability, and concentration difficulty compared to placebo. The researchers proposed that the anti-neuroinflammatory effects of Lion's Mane, combined with NGF support in limbic areas, may explain mood benefits.
A 2023 preclinical study identified a specific compound in Lion's Mane — N-de phenylethyl isohericerin (NDPIH) — that promotes hippocampal neurogenesis and shows antidepressant-like effects. While this research is at an early stage, it adds mechanistic support to the clinical and traditional observations about mood.
For Irish adults with family histories of neurodegenerative conditions, Lion's Mane research is particularly encouraging. Animal studies have consistently shown neuroprotective effects in Alzheimer's, Parkinson's, and traumatic brain injury models. The erinacines, in particular, have been shown to reduce amyloid beta plaque accumulation in animal Alzheimer's models.
This does not mean Lion's Mane treats Alzheimer's disease — the human trials are not there yet. But as a long-term neuroprotective strategy for healthy middle-aged adults, the risk-benefit profile is extremely favourable. It is safe, well-tolerated, and the potential upside is significant. For anyone watching a parent navigate cognitive decline and wondering what they can do proactively, Lion's Mane is one of the few supplements where the underlying science genuinely supports optimism.
NGF is important not just in the brain but in the peripheral nervous system. Lion's Mane has been studied for peripheral neuropathy — nerve damage in the extremities that causes pain, numbness, and tingling, often seen in diabetes. A 2020 pilot study in people with mild diabetic neuropathy found that Lion's Mane supplementation improved nerve conduction velocity and reduced symptoms. While this research is preliminary, it opens an interesting avenue for one of Ireland's most common chronic conditions — diabetes affects approximately 225,000 Irish adults.
The Lion's Mane market in Ireland varies enormously in quality. Key things Pat Coffey at The Honey Pot recommends looking for:
Lion's Mane supplements are widely available in Irish health food stores including The Honey Pot. Fresh Lion's Mane mushrooms are increasingly available at Irish farmers' markets and some specialty grocers, particularly in Dublin and Cork. Several Irish mushroom cultivation companies now produce fresh Lion's Mane, and grow-your-own kits are available online if you want a reliable supply of fresh fruiting bodies.
As a food, Lion's Mane has an appealing meaty texture and mild seafood-like flavour — it works well pan-fried in butter or olive oil. However, cooking temperatures denature some of the active compounds, so culinary Lion's Mane is not equivalent to a well-made extract supplement for medicinal purposes.
"Lion's Mane is one of the most exciting supplements I've seen come into the market in 20 years," says Pat. "The research on nerve growth factor is genuinely compelling, and the customers who try it consistently come back for more. I recommend a good dual-extract, starting at around 500–1000mg per day, taken consistently for at least 8 weeks before judging results. It's one of those supplements where patience is rewarded." The Honey Pot at 14 Abbey Street, Clonmel stocks quality Lion's Mane products and ships nationwide through thehoneypotonline.ie — free delivery on orders over €55.