The Mycelium Problem: Why What’s on the Label Isn’t What’s in the Bottle
Shane SchoolmanA deep dive into Lion’s Mane chemistry, the mycelium-on-grain problem, and what the research actually shows about therapeutic potency.
There’s an argument that has quietly taken over the functional mushroom industry. It goes something like this: mycelium is where the real action is. More bioavailable. More potent. The compounds that actually cross the blood-brain barrier and do something. And if you want those compounds — specifically the ones that drive neurological benefit — you need mycelium.
It’s a compelling argument. And for Lion’s Mane, it’s partially grounded in legitimate science.
The problem is what the industry did with it.
The Chemistry of Lion’s Mane — What’s Actually Where
Let me start with what the research actually says, because the compound picture is more nuanced than most supplement marketing lets on.
Lion’s Mane produces two primary families of neuroactive compounds. Hericenones — aromatic meroterpenoids found exclusively in the fruiting body. And erinacines — cyathane diterpenoids found predominantly in the mycelium. Both families have been documented as nerve growth factor (NGF) stimulators since the early 1990s. Both cross the blood-brain barrier. And for decades, researchers treated them as complementary — two different tissues, two different compound profiles, both pharmacologically interesting.
This isn’t a contested point. A 2015 literature review by Mendel Friedman, a USDA researcher with no commercial stake in the outcome, cataloged approximately 70 characterized bioactive secondary metabolites in Hericium erinaceus — including hericenones, erinacines, hericerins, hericenes, resorcinols, sterols, polysaccharides, volatile aroma compounds, erinaceolactones, and isoindolinones. The compound diversity across the organism is remarkable. But it isn’t distributed evenly between tissues.
The fruiting body contains the majority of that chemical diversity. The mycelium contributes primarily one compound class: erinacines.
That distinction is important. It’s also where the industry’s argument breaks down.
The Mycelium-on-Grain Problem
Here’s what the supplement industry doesn’t tell you about mycelium products.
Commercial mycelium for supplements is almost universally grown on grain — typically rice, oats, or sorghum. The mycelium colonizes the substrate, threading through it until the two are inseparable. When manufacturers harvest and process it, they’re processing both the mycelium and the grain it grew on. Independent testing has repeatedly found that products labeled as “lion’s mane mycelium” contain 60–70% grain starch by weight.
You are paying for a mushroom supplement and receiving, by mass, mostly grain.
Now layer in the erinacine concentration data. A 2024 study on erinacine A content across multiple Lion’s Mane strains found concentrations ranging from 0.23 mg/g to 42.16 mg/g — a 183-fold difference — depending on strain genetics and cultivation conditions. The only clinical trial that has demonstrated meaningful cognitive benefit from erinacine A used liquid-fermented mycelium with HPLC-verified 5 mg/g erinacine A content, grown in a specific submerged fermentation process with controlled nitrogen sources and calcium carbonate.
A 2025 peer-reviewed study in Fungal Biology and Biotechnology confirmed that substrate composition is a critical determinant of erinacine production — with different media formulations producing up to 100-fold differences in erinacine C content from the same organism. The same study confirmed, by HPLC, that fruiting body tissue contained no detectable erinacines from the four compounds tested.
So the mycelium industry’s argument runs like this: erinacines are in the mycelium, and erinacines are what produce neurological benefit. What they omit is that actually delivering meaningful erinacine concentrations requires liquid bioreactor cultivation, strain selection, HPLC verification, and the complete absence of grain dilution — none of which describe a typical mycelium-on-grain supplement.
A grain-colonized mycelium capsule with no verified erinacine content is not a mycelium product in any meaningful sense. It’s a grain product with marketing copy.
What the Fruiting Body Actually Delivers
Here’s where the argument gets interesting — and where the industry narrative breaks down from the other direction too.
While mycelium advocates have been staking their claim on erinacines, clinical trials using fruiting body extract have been quietly showing cognitive benefit.
A 2019 double-blind, placebo-controlled study found that oral intake of fruiting body supplements significantly improved cognitive functions over 12 weeks as measured by MMSE scores, with researchers attributing the effect to hericenones and the broader chemical compounds present in the tissue. A 2025 acute trial using 3g of a 10:1 fruiting body extract showed task-specific improvements in psychomotor function in healthy young adults within 90 minutes of consumption.
These results exist without a single milligram of erinacine.
What’s producing the effect? The honest answer is: we don’t fully know yet. And that might actually be the point. The fruiting body delivers hericenones, polysaccharides, beta-glucans, polyphenols, sterols, and a complex matrix of compounds that appear to act synergistically on neurological function. The compound diversity of the fruiting body is substantially broader than the mycelium’s, and clinical evidence suggests that diversity is doing something.
This is my hypothesis: the question isn’t fruiting body versus mycelium in the abstract. The question is whether you can actually deliver a therapeutic dose of the compounds you’re claiming to provide. A quality fruiting body extract — properly concentrated, dual extracted, with verified beta-glucan content — can deliver a meaningful dose of hericenones, polysaccharides, and the full compound matrix that has shown up in clinical trials. A mycelium-on-grain capsule with no erinacine verification delivers neither.
It is simultaneously failing at being a mycelium product and failing at being a fruiting body product.
The Conflict of Interest Problem
I want to be direct about something, because I think intellectual honesty matters in this space.
The most rigorous recent paper on substrate-dependent erinacine production was authored by the research team at Fungi Perfecti — Paul Stamets’ company. They have a commercial interest in the outcome. That’s worth knowing.
But their core findings are corroborated across multiple independent research groups going back years. The substrate-dependency of erinacine production isn’t a novel claim invented by a supplement company — it’s established mycology. The Fungi Perfecti paper ran the most systematic recent experiment on the question, and their HPLC results confirming zero detectable erinacines in fruiting body tissue are consistent with the broader literature. I cite it because it’s the best data available on this specific question, not because it’s the only data.
This is how we approach research at Mycolove. We cite what the evidence shows. We flag where the evidence has limits. We don’t pretend certainty we don’t have.
What This Means for How You Read a Label
If you’re evaluating any Lion’s Mane supplement — mycelium or fruiting body — here are the questions that actually matter.
For mycelium products: Is the erinacine A content HPLC-verified? What is the concentration in mg/g? Was this grown in liquid culture or on grain substrate? If the label says “mycelium” but doesn’t specify erinacine A content, you have no way to know whether you’re getting a therapeutic dose or a grain product.
For fruiting body products: What’s the beta-glucan content? Is it dual extracted — water and alcohol — to pull both polysaccharides and lipid-soluble compounds? Is the extract ratio specified? A 10:1 extract is meaningfully different from a 4:1 extract.
For either: Is there a COA? Does the company show their work?
These aren’t trick questions. They’re the baseline for any supplement you’re putting in your body. The fact that most brands in this space can’t answer them is the problem.
Where We Stand
At Mycolove, we built around full-spectrum fruiting body extraction because the compound matrix is broader and more diverse than any single-pathway product can capture. We’re not anti-mycelium. We’re anti-unverified.
And we hold ourselves to the same standard we’re describing here. Which means I’m not going to tell you to just take our word for it either. We’re currently in the process of third-party HPLC testing across our product line — samples are submitted, results are pending. When those COAs come back, they’ll be published on our site. No cherry-picking, no selective disclosure. Everything.
That’s what radical transparency actually looks like. Not a marketing claim — a commitment we’re in the process of fulfilling. Watch this space.
— Shane Schoolman, Founder | Mycolove Farm | USDA Certified Organic
This is Part One of an ongoing series examining the chemistry behind fruiting body versus mycelium across functional mushroom species. Next up: Cordyceps — where the mycelium argument has a genuinely different scientific basis, and the answer is more complicated than either side wants to admit.
Sources
Friedman M. (2015). Chemistry, Nutrition, and Health-Promoting Properties of Hericium erinaceus (Lion’s Mane) Mushroom Fruiting Bodies and Mycelia and Their Bioactive Compounds. J Agric Food Chem 63(32): 7108–7123.
Liu et al. (2024). Isolation and Evaluation of Erinacine A Contents in Mycelia of Hericium erinaceus Strains. PMC11172171.
Doar et al. (2025). Influences of substrate and tissue type on erinacine production and biosynthetic gene expression in Hericium erinaceus. Fungal Biology and Biotechnology. PMC11969743.
Li et al. (2020). Prevention of Early Alzheimer’s Disease by Erinacine A-Enriched Hericium erinaceus Mycelia Pilot Double-Blind Placebo-Controlled Study. Frontiers in Aging Neuroscience.
Saitsu et al. (2019). Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomed Res. PMID: 31413233.
Docherty et al. (2025). Acute effects of a standardised extract of Hericium erinaceus on cognition and mood in healthy younger adults. Frontiers in Nutrition. PMC12018234.
Mori et al. (2008). Neurohealth Properties of Hericium erinaceus Mycelia Enriched with Erinacines. PMC5987239.