Beta-Glucan vs. Polysaccharides: The Number That Actually Matters

Beta-glucan (1,3/1,6) is the primary active polysaccharide in functional mushrooms — reishi (Ganoderma lucidum), lion’s mane (Hericium erinaceus), cordyceps, and turkey tail (Trametes versicolor) — and it is the one number worth looking for on an extract label. But the market often shows you a different, bigger, more impressive number: “total polysaccharides.” This guide explains the difference between the two, why the second one is easy to inflate, and how to read the right one — using our own numbers, from open lab reports, as a live example.

What is the difference between beta-glucan and “polysaccharides”?

“Polysaccharides” is an entire chemical family — any long chain of sugars qualifies: fungal beta-glucan, grain starch, and fibers like inulin and pectin all count. Beta-glucan 1,3/1,6 is one specific polysaccharide — the one built into the mushroom’s cell wall, and the one that mushroom research actually studies. A label declaring “polysaccharides” says “there are some long sugars in here”; a label declaring beta-glucan 1,3/1,6 says exactly what is in there, and how much.

This distinction is not chemical pedantry — it is the difference between a mushroom product and a substrate product. The fungal cell wall is built of beta-glucans with 1,3 and 1,6 linkages (in oats, by comparison, the linkage is different — 1,3/1,4 — so even “beta-glucan” alone is worth a second look at which kind). Starch, on the other hand, is an alpha-glucan — the polymer of grain. The two look identical inside a “total polysaccharides” figure, and completely different on a specific beta-glucan line.

Why is “total polysaccharides” so easy to inflate?

Because it counts everything. A mycelium product grown on grain arrives with the substrate’s starch inside — and starch is a polysaccharide, so it counts. A producer who adds a filler fiber like inulin — also a polysaccharide, also counted. That is how a product can display “60% polysaccharides” while the lion’s share is starch and added fiber, with very little fungal beta-glucan at all. The big number isn’t technically lying — it just says nothing about the mushroom.

Nor is this theoretical. On a real test certificate of a cordyceps product on the market that reached us, the fructans (inulin) line showed 14%–17% — a filler fiber inflating “total polysaccharides” by nearly half, while the beta-glucan line itself was lower than ours. On our reports, that exact same line reads “not detected.” To learn how to spot this yourself on a full report, line by line, see our guide: How to Read a Mushroom Supplement COA.

What is a good beta-glucan percentage in a mushroom extract?

The benchmark that repeats across public market testing is clear: mycelium-on-grain products typically test below 7% beta-glucan, because most of their powder is grain substrate; quality fruiting body measures in the 25%–40% range. Every number needs two critical qualifiers: which method measured it, and what it was measured on — raw material or the finished product. Without both, even “40%” is just a slogan.

Note the nuance: our numbers are measured on the finished extract — the liquid you actually drink, after extraction — not on raw-material powder. A fair comparison between products must ask what the number was measured on; otherwise you are comparing apples to peels. And why an extract made from fresh fruiting body reaches numbers like these at all — that story is in Fresh vs. Dried mushroom extract.

How is beta-glucan measured properly — and what does “dry basis” mean?

The reliable measurement is enzymatic and specific: enzymes that break down beta-glucan in particular, so starch and other sugars are not counted by mistake. Our extracts are tested with the Megazyme Mushroom and Yeast beta-glucan assay — a method that chemically separates beta-glucan from alpha-glucan and reports each one on its own line. Generic methods that measure “total sugars” or “total polysaccharides” simply cannot tell them apart — which is why their number is bigger, and emptier.

“Dry-weight basis” means the percentage is calculated after removing the water: the liquid is taken out of the extract, and what remains — the solids — is what gets measured. So 25.65% in our reishi means: of every gram of dry matter in the extract, about a quarter is fungal beta-glucan. It is the only way to compare products fairly, since water content varies from product to product — and it is also why we do not convert the percentage into “mg per ml”: that number would require assumptions we are not willing to make without measuring.

What is alpha-glucan, and why is “not detected” the proof?

Alpha-glucan is the starch family — amylose and amylopectin — the polymers of grain. A mushroom contains almost none; ground grain substrate is full of them. That makes the alpha-glucan line of a lab report a chemical grain detector: “not detected” means there is no ground substrate in the extract, while a high number means you are paying for grain at mushroom prices. It is the line that settles the “fruiting body or mycelium” debate with a single measurement.

On the reports of all four of our tested extracts, the amylose and amylopectin lines — and the fructans (inulin) line as well — read “not detected” (below the detection limit).

What numbers were measured in our extracts?

These are the numbers from our open test reports — each measured at TÜV Austria on the finished extract, by the Megazyme method, on a dry-weight basis, with a certificate number you can verify directly with the lab:

And in the same breath, what this table does not claim: the 23.21% belongs to the combined Turkey Tail & Reishi extract — not to turkey tail alone, which was not sent for a separate test, so we do not cite a number for it. All of our tests are open on the lab results page, which also hosts the full science section on beta-glucans — definitions, mechanism, and research references; this page is its consumer edition, not a replacement.

What does beta-glucan do — and what don’t we know yet?

Fungal beta-glucans are studied mainly for their interaction with the immune system: immune cells carry a dedicated receptor called Dectin-1 that recognizes the 1,3-beta-glucan structure, and research shows this recognition depends on the molecule’s exact architecture. Further research explores how gut bacteria break beta-glucans down as dietary fiber. That is why the structure — 1,3/1,6 — is part of the metric, not just the percentage.

And what don’t we know yet? Plenty. Most mechanistic beta-glucan research comes from lab and model studies, and human clinical trials measuring tangible outcomes are still accumulating. A high beta-glucan percentage proves the product is made from real mushroom at real concentration; it is not a medical promise, and anyone selling it as one has crossed the line from measurement into marketing. We stay on the measurement side: the number, the method, and the open report. And for the research itself — on the mushrooms, not the products — our research hub, filtered to quality-control studies, is waiting.

How do you check a label with three questions?

Facing any mushroom product, in any store, three questions are enough: One — how much beta-glucan 1,3/1,6, explicitly, not “polysaccharides”? Two — measured how and on what: enzymatically, on the finished product? Three — what does the alpha-glucan line show, and is there an open third-party lab report with a verifiable certificate number? A brand that answers all three transparently has earned trust. A brand that answers “we have a high polysaccharide content” has answered — just not what you asked. The full checklist, on a real report, is in our COA reading guide.

The Bottom Line

“Polysaccharides” is a number built to be seen; beta-glucan 1,3/1,6 is a number built to be measured. The difference between them is the whole difference between ground grain substrate and real mushroom — and it is exposed by three lines of a lab report: the beta-glucan percentage, the measurement method, and the alpha-glucan line. Our numbers — 28.16%, 25.65%, 23.93%, 23.21% — are open for your inspection, certificate by certificate. From now on, when a label says “60% polysaccharides,” you will know exactly which question to ask.

Frequently Asked Questions

Scientific Sources (Peer-Reviewed)

1. Wu DT, et al. Evaluation on quality consistency of Ganoderma lucidum dietary supplements collected in the United States. Scientific Reports, 2017. View on PubMed
2. Ohno N. Fungal beta-glucans: structure and effect on host immune responses. Yakugaku Zasshi, 2021. View on PubMed
3. Anaya EU, et al. Dectin-1 multimerization and signaling depends on fungal beta-glucan structure and exposure. Biophysical Journal, 2023. View on PubMed
4. Yamanaka D, et al. Quantification of mushroom-derived soluble beta-1,6-glucan using the function-modified recombinant beta-1,6-glucanase. International Journal of Medicinal Mushrooms, 2020. View on PubMed
5. Zhang X, et al. Edible mushroom polysaccharides: structural characteristics, chemical modification strategies, and structure-activity relationship: A review. International Journal of Biological Macromolecules, 2025. View on PubMed
6. Yu L, et al. Interaction of beta-glucans with gut microbiota: Dietary origins, structures, degradation, metabolism, and beneficial function. Critical Reviews in Food Science and Nutrition, 2024. View on PubMed

Research data source: PubMed. Commercial numbers on this page come exclusively from our open lab reports. This content is an educational review and does not constitute medical advice.