Mushroom supplements are sold on words — fruiting body, extract ratio, polysaccharides — and only one of them is a specification. This is what each term is actually measuring, why one of the numbers can be inflated by the growing medium, and how to ask for the paperwork that settles it.
The word that does the least work
Most mushroom labels lead with a polysaccharide percentage. It is a real measurement, honestly obtained, and it is close to useless for comparing products.
What a polysaccharide is
A chain of sugar units. That is the whole definition. It is a category roughly as specific as "protein" — enormous, and containing things with nothing in common but their architecture.
Why starch qualifies
Starch is a polysaccharide. So is glycogen, and so is cellulose. A product grown on rice or sorghum can therefore post a high polysaccharide number that is substantially grain.
Beta-glucans, specifically
What they are
Glucose chains with a particular set of links. In fungi the backbone runs through beta-1,3 bonds with beta-1,6 branches coming off it — a structure the cell wall is built from.
The bond pattern is the identity. Cereal beta-glucans, from oats and barley, are beta-1,3 and beta-1,4 and are a different material despite sharing the name.
Why the number resists padding
Starch is an alpha-glucan: the same sugar, a different linkage. An assay that distinguishes the two cannot be fooled by adding grain, which is exactly why a beta-glucan percentage carries information a polysaccharide percentage does not.
How the two numbers are measured
The precipitation route
Extract the material in hot water, add ethanol, and weigh what falls out. What settles is "crude polysaccharide" — a mixed fraction, reported as a single percentage.
The subtraction route
Break the sample down and measure total glucan as glucose. Separately, measure the alpha-glucan alone using an enzyme that acts on starch. Subtract the second from the first, and what remains is beta-glucan.
The second method costs more and takes longer. It is also the only one whose answer means what a buyer thinks it means.
| Method | What it counts | Can grain inflate it? |
|---|---|---|
| Hot water, ethanol precipitation | Everything that precipitates: beta-glucans, starch, other polysaccharides | Yes |
| Total glucan minus alpha-glucan | Beta-glucan only | No — starch is measured and removed |
Fruiting body and mycelium on grain
Two different materials
The fruiting body is the mushroom — the part a forager would recognise. Mycelium is the fine root-like network it grows from, and in commercial production that network is usually cultivated on sterilised grain.
Why the grain travels with it
Mycelium cannot practically be separated from the substrate it has grown through. The standard practice is to harvest and mill the whole colonised block, so the grain becomes part of the powder.
This is disclosed. The label says "mycelium", and that is accurate. What it does not say is that a meaningful fraction of the weight is the medium.
The case for mycelium, made fairly
It is faster to grow, cheaper, and often produced domestically rather than imported. Mycelium is also genuinely a different organism stage that produces compounds a fruiting body does not, and researchers study it in its own right.
The objection is narrow and worth keeping narrow: it is about grain arriving in the capsule uncounted, not about mycelium as a material. That distinction is drawn out in what "100% fruiting body" means on a lion's mane label.
Why "8:1 extract" says less than a percentage
What the ratio is a ratio of
Eight units of starting material reduced to one unit of extract. It describes a manufacturing step, and there is no regulatory definition fixing how it must be calculated.
Three things it does not settle
- What went in. Eight kilos of fresh mushroom and eight kilos of dried mushroom are very different starting points, and mushrooms are mostly water.
- Which part went in. A ratio applied to colonised grain concentrates whatever was in the grain.
- What came out. Extracts are frequently carried on maltodextrin or another flow agent, and the ratio does not describe the final blend.
A ratio is not dishonest. It is simply a description of a process where a specification was needed.
| What the label says | What it constrains | What it leaves open |
|---|---|---|
| "8:1 extract" | A concentration step happened | Starting material, plant part, moisture, carriers, final content |
| "30% polysaccharides" | A measured fraction precipitated | How much of that fraction is starch |
| "Fruiting body" | Which part of the organism was used | How much active material it carries |
| "At least 25% beta-glucans" | A floor on a specific measured compound class | Whether the lot in your hand was tested |
What a stated percentage does not promise
It is a compositional specification, not an outcome. A beta-glucan floor tells you what is in the capsule and nothing whatsoever about what happens after it is swallowed.
It is also a claim until a document supports it, which is where the certificate of analysis comes in.
How to ask for the lot certificate
Could you send the certificate of analysis for lot [number printed on the pouch]?
I am looking for the beta-glucan result and the method used to obtain it.
What a real one carries
A specific lot number matching the pack, a test date, the analytical method named, the result, and the name of the laboratory that produced it. A third-party laboratory is better than the supplier's own, though a supplier certificate is not worthless.
What often arrives instead
A specification sheet — what the product is meant to contain — rather than a result for a particular batch. Or a certificate with the lot field empty. Or a polysaccharide figure where a beta-glucan figure was requested.
None of these are refusals, and a small brand may simply not hold the document. The reply is still information, in the same way a response about a blend total is. That parallel is drawn in what a proprietary blend actually hides.
What a good mushroom row looks like
Species named in Latin as well as English. Plant part stated. A standardisation figure with the compound class named, not just "polysaccharides". And an amount, outside any blend.
Four facts, all of which fit inside one parenthetical, and all of which are checkable. Where they sit on a panel is covered in how to read a Supplement Facts panel in about sixty seconds.
The three-second version
- Find the word after the species: fruiting body, or mycelium.
- Find the standardisation: beta-glucans, or polysaccharides, or nothing.
- If it says beta-glucans with a percentage, ask for the lot certificate.
Where we stand
The lion's mane in Weal Focus is specified as 100% fruiting body, standardised to at least 25% beta-glucans, at 400 mg — and the beta-glucan figure is one we hold a lot certificate for rather than one we print ahead of the paperwork.
That is a disclosure standard, not a performance claim. The point of the whole exercise is that a reader can apply the same three checks to any pack on the shelf, including ours.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Sources for every figure, with the population studied in each, are on our citations page.