Day: October 21, 2025

If you’re reading this, you either replied to our email about Lion’s Mane and memory, or you’re one of the people considering joining our community replication study. Either way, you deserve to know exactly what the science says. Not marketing spin. Not cherry-picked data. The full picture. This breakdown covers the two most important Lion’s Mane studies for cognitive function: Let’s start with the study that changed everything. Study #1: The Mori Study (2009) Full Citation Mori K, Inatomi S, Ouchi K, Azumi Y, Tuchida T. “Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial.” Phytother Res. 2009 Mar;23(3):367-72. Read the full study here → Why This Study Matters Before 2009, Lion’s Mane (Hericium erinaceus, also called Yamabushitake in Japan) was primarily studied for: But there was no human data showing it could actually improve cognitive function in people with memory concerns. The Mori study changed that. It’s the first (and for a long time, the only) double-blind, placebo-controlled clinical trial testing Lion’s Mane specifically for cognitive impairment in older adults. This is the study that every reputable Lion’s Mane supplement company cites when they talk about “clinically studied for brain health.” The question is: Does what’s in their bottle match what was in this study? More on that later. Study Design: What They Actually Did Population: What is MCI? It’s the stage between normal age-related memory decline and dementia. People with MCI notice memory problems, others might notice too, but it’s not severe enough to interfere significantly with daily life. About 10-20% of people over 65 have MCI, and it often (but not always) progresses to dementia. Intervention: Source Material: The tablets contained dried powder of Lion’s Mane fruiting bodies (the actual mushroom, not mycelium grown on grain). The mushroom was cultivated in Japan specifically for this study. Key Detail: This was a double-blind study, meaning neither the participants nor the researchers knew who was getting Lion’s Mane vs. placebo until after the data was analyzed. This is the gold standard for eliminating bias. How They Measured Cognitive Function The researchers didn’t just ask people “do you feel smarter?” They used a validated assessment tool called the HDSR (Hasegawa Dementia Scale-Revised) which is widely used in Japan to assess cognitive function. The HDSR tests: Scores range from 0-30. Lower scores indicate greater cognitive impairment. Participants were tested at: The Results: What Actually Happened Here’s where it gets interesting. At baseline (week 0): During treatment (weeks 8-16): The Lion’s Mane group showed progressive improvement in cognitive scores throughout the 16 weeks: The placebo group? Their scores stayed essentially the same or declined slightly (which is expected with MCI). Statistical significance: The difference between groups was significant at week 12 (p<0.05) and highly significant at week 16 (p<0.01). In plain English: This wasn’t chance. This was a real, measurable improvement. After stopping (week 20): This is the part most supplement companies don’t mention. Four weeks after participants stopped taking Lion’s Mane, their cognitive scores declined back toward baseline. They didn’t drop all the way back immediately, but the trajectory was clear: the benefits required ongoing supplementation. What Does This Actually Mean? Let’s be honest about what this study shows and what it doesn’t. What it DOES show: What it DOESN’T show: Clinical significance: A 4-point improvement on the HDSR (which is roughly what the Lion’s Mane group achieved) might sound small, but in the context of MCI, it’s substantial. For reference: Safety and Tolerability This is important: No adverse events were reported in the Lion’s Mane group. No stomach issues. No headaches. No interactions. No participants dropped out due to side effects. Compare this to pharmaceutical cognitive enhancers, which often cause: Lion’s Mane appears to be remarkably well-tolerated, even at 3g daily for 16 weeks. Study Limitations (Being Honest) No study is perfect. Here are the limitations: The Study-Washing Problem Here’s why this study matters for choosing a Lion’s Mane supplement: What the study used: What most supplements provide: To match the Mori study, you would need to take: This is why people try Lion’s Mane and feel nothing. They’re not taking what the study used. Study #2: The Mechanism (Martínez-Mármol et al., 2023) Full Citation Martínez-Mármol R, Chai Y, Conroy JN, et al. “Hericerin derivatives activates a pan-neurotrophic pathway in central hippocampal neurons converging to ERK1/2 signaling enhancing spatial memory.” J Neurochem. 2023;165(6):791-808. Read the full study here → Why This Study Matters The Mori study proved that Lion’s Mane works. The Martínez-Mármol study figured out how. This 2023 study from the University of Queensland (Australia) is groundbreaking because it: In other words: This isn’t folk medicine anymore. This is molecular neuroscience. What They Discovered The Active Compounds: The researchers isolated and identified specific molecules from Lion’s Mane: These are aromatic compounds with prenyl side chains — basically, small fat-soluble molecules that can cross the blood-brain barrier. The Mechanism: These compounds promote neurite outgrowth (the growth of new neuron branches) and neuritogenesis (the formation of new neural connections) through activation of the ERK1/2 signaling pathway. Here’s what that means in plain English: Your brain has signaling pathways that tell neurons to grow, connect, and strengthen their connections. One of the most important is the ERK1/2 pathway, which leads to: The novel finding: Hericene A activates ERK1/2 through a TrkB-independent pathway. Most neurotrophic compounds (like BDNF, brain-derived neurotrophic factor) work by activating the TrkB receptor. Hericene A doesn’t. It uses a completely different route to arrive at the same destination (ERK1/2 activation). This means Lion’s Mane can potentially work synergistically with other neurotrophic factors, rather than competing for the same receptor. The Animal Study Results They tested Lion’s Mane extracts in mice for 31 days: Doses tested: Results: The most remarkable finding: Purified hericene A at just 5mg/kg was equally potent as 250mg/kg of crude extract. That’s a 50-fold concentration advantage. Why This Matters for Humans Translating mouse doses to human doses isn’t straightforward, but researchers often use a conversion factor of