Mushroom supplement labels can get technical quickly: polysaccharides, beta-glucans, alpha-glucans, terpenoids.
These terms describe different compounds, yet they are sometimes presented as though they tell you the same thing about a mushroom product. They do not.
Understanding the difference can help you look past a big number on a label and ask the more useful question: what exactly was measured?
Polysaccharides: the broad category
Polysaccharides are complex carbohydrates made from chains of sugar molecules. They occur throughout nature - in plants, fungi, and many foods - and perform numerous structural and biological functions.
Mushrooms contain multiple types of polysaccharides. So when a supplement advertises "high polysaccharides," that number by itself does not necessarily tell you how much mushroom beta-glucan the product contains.
That distinction matters because a broad polysaccharide measurement can include carbohydrates that came from somewhere other than the fungal compounds you are trying to evaluate.
Beta-glucans: a more useful mushroom marker
Beta-glucans are a specific family of polysaccharides. Fungal beta-glucans often include beta-(1→3) linked glucose with beta-(1→6) branching, although structure varies among species and preparations.
Beta-glucans are among the most intensively studied mushroom polysaccharides. For supplement comparison, beta-glucan content is usually more informative than a generic total-polysaccharide percentage.
Beta-glucans vs. alpha-glucans
Not every glucan in a mushroom supplement is a beta-glucan. Alpha-glucans include carbohydrates such as starch.
This becomes especially relevant when mycelium is cultivated on rice, oats, sorghum, or another grain and that substrate remains in the harvested material. Residual grain can contribute substantial starch, so a broad carbohydrate or polysaccharide number can look impressive without telling you how much fungal beta-glucan is actually present.
A 2026 analytical review in the Journal of AOAC International emphasizes that starch-rich formulations can complicate glucan testing. That means the measurement method matters too: a beta-glucan number is most useful when the method properly distinguishes beta-glucans from alpha-glucans and other starches.
Why “total polysaccharides” can be misleading
Imagine two mushroom products. One reports a very high percentage of total polysaccharides but does not tell you how much is beta-glucan. The other reports a defined beta-glucan specification.
The first number may be larger, but that does not automatically mean it contains more of the fungal compounds you are trying to evaluate.
Specific measurements are more informative than broad ones. That is why beta-glucan disclosure is generally more useful than relying on a generic polysaccharide claim.
So where do terpenoids fit?
Terpenoids are different. They are not polysaccharides at all.
They are a large family of naturally occurring compounds found throughout plants and fungi. Certain mushroom species have particularly notable terpenoid profiles.
Reishi (Ganoderma species) is the classic example. Reishi contains both polysaccharides - including beta-glucans - and a diverse group of triterpenoids, including compounds commonly referred to as ganoderic acids.
Recent scientific reviews continue to identify polysaccharides and triterpenoids as two major classes of Ganoderma constituents. This is also one reason extraction method matters: water and alcohol do not recover exactly the same chemical fractions.
Does every mushroom need a terpenoid specification?
No. Different mushroom species have different chemical profiles.
A useful label should not simply collect as many impressive-looking percentages as possible. The specification should make sense for the species and ingredient being sold.
For many mushroom extracts, beta-glucan content is a useful quality marker. For mushrooms such as Reishi, terpenoids may provide additional information - but a quantified terpenoid level should only be advertised when it has actually been measured and substantiated.
Why Noomadic specifies Beta-D-Glucans
Noomadic uses fruiting-body mushroom extracts only, and all mushroom extracts used in our mushroom supplements are standardized to 30% Beta-D-Glucans.
And although ingredients such as Reishi naturally contain other compounds, including triterpenoids, we do not advertise a specific terpenoid percentage unless analytical documentation supports that number.
What to look for on a mushroom supplement
- What part of the mushroom is used?
- Is it an extract?
- What extraction method is used?
- Does the manufacturer disclose beta-glucan content?
- Is the number beta-glucans specifically - or only total polysaccharides?
- Could grain or starch be contributing to the carbohydrate measurement?
- Are other compounds, such as terpenoids, actually tested before a percentage is claimed?
The bottom line
Polysaccharides are a broad family of carbohydrates. Beta-glucans are a specific type of polysaccharide and provide a more useful measurement when evaluating many functional mushroom extracts.
Alpha-glucans can include starches and other carbohydrates that should not be confused with fungal beta-glucans. Terpenoids are an entirely different class of compounds and can be particularly relevant to species such as Reishi.
A good mushroom supplement should make these distinctions clearer - not hide them behind a larger, less meaningful number.
Know what was measured. Know what you are actually getting.
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