Beta-Glucans vs. Total Polysaccharides
Why "beta-glucan" and "polysaccharides" on a mushroom label are not the same number, how they are measured, why starch complicates it, and what a high figure does not prove.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
The short answer: polysaccharides are long chains of sugars, and beta-glucans are one kind of them. A label may show one number, the other, or both, and the two can differ because they measure different things, sometimes by different methods. Neither number shows that a product will help your health.
How the sources define the terms
Reviews describe edible fungal polysaccharides as including alpha- and beta-glucans, heteroglucans, galactans and mannans. [1] In oyster mushroom (Pleurotus ostreatus), a review says the water-soluble polysaccharides are mainly beta-glucans with beta-(1→3)(1→6)-linked glucose backbones. [2] In plain terms, beta-glucan is a subtype, while "total polysaccharides" is a broader group.
Alpha-glucans matter because the usual beta-glucan method subtracts them from the total (see the table). Mushroom products that include grain, such as mycelium on grain, can carry starch. In a chaga (Inonotus obliquus) analysis, beta-glucan quantification and iodine-starch tests confirmed a starch-rich composition in fermented grain products and its absence in authentic chaga. [3] See Mycelium Grown on Grain.
Why two label numbers differ
| Question | What the source found | Strength of evidence |
|---|---|---|
| How is beta-glucan usually measured? | The longstanding indirect approach subtracts enzymatically measured alpha-glucans from total glucans obtained by acid hydrolysis. [4] | Method description |
| Does the usual method have limits? | A 2026 methods paper says it is increasingly challenged by supplement formulations containing resistant starches, trehalose and sweeteners such as maltitol. [4] Its authors work for a laboratory-testing company and describe refinements to the workflow. | Laboratory methods |
| Do species and strains differ? | In a study of cultivated mushrooms, shiitake (Lentinula edodes) strains had beta-glucan from 13.433% to 26.190%, and one lion's mane (Hericium erinaceus) strain had 17.442%. [5] | Laboratory analysis of specific cultivated strains |
| Does the structure matter? | A review reports that beta-(1→3)-glucans with beta-(1→6) branches and triple-helix shapes show strong immune effects in laboratory work, and flags extraction standardization and quality control as challenges. [1] | Mostly preclinical |
| Does a higher number mean a better product? | Proper evidence not found. We searched PubMed for beta-glucan label, supplement and assay terms and found methods and composition papers, not trials linking a label percentage to a health outcome. | Insufficient evidence |
A result also depends on the preparation: the amount of polysaccharide in a powder, a hot-water extract and a fruiting body can differ, and findings for one do not transfer to another. See Mushroom Extraction Methods.
What this means when you read a label
- Look for whether the number is "beta-glucan" or "polysaccharides," and whether the label says how it was measured.
- Ask whether starch or grain is in the product.
- Treat the figure as a composition detail. It is not a dose recommendation, and a clinician or pharmacist decides what is right for a person.
Beta-glucan also occurs in foods. For oats and barley, see Oats and Beta-Glucan in Foods. Findings for one source do not automatically apply to another.
Frequently asked questions
Is beta-glucan the same as polysaccharide?
No. Beta-glucan is one type of polysaccharide; polysaccharides also include alpha-glucans, galactans and mannans. [1]
Why can total polysaccharides be higher than beta-glucan?
A broader measure covers more kinds of sugar chain, and products that contain grain can carry starch. [1][3]
Is a product with more beta-glucan more effective?
Proper evidence not found. The papers we read describe measurement and composition, not health results by label number. [4][5]
Do all mushrooms have the same beta-glucan?
No. One study found different values in shiitake strains and a lion's mane strain. [5]
Does the beta-glucan in mushrooms act like oat beta-glucan?
Proper evidence not found in the sources we read for a direct comparison. See Oats for oat beta-glucan.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety
Mushroom supplements can interact with medicines or carry risks with certain medical conditions or before surgery, so tell your health care providers about all supplements. [6] A cancer center advises people on immunosuppressants to talk to their provider about reishi, saying it may not be safe for them. [7] Many supplements have not been tested in pregnant women, nursing mothers or children. [6] See How Interactions Work and Quality Testing and Certifications.
References
- Zhang X, Duan Y, Xue J, Chen S, Wang H. Edible mushroom polysaccharides: structural characteristics, chemical modification strategies, and structure-activity relationship: a review. Int J Biol Macromol. 2025. PubMed 40651640. Read 2026-10-23.
- Tang W, Zhang Y, Yan L, et al. Preparation, structural features, bioactivities, and food application of oyster mushroom polysaccharides: a review. J Food Sci. 2026. PubMed 42720047. Read 2026-10-23.
- Windsor C, Kreynes AE, Chilton JS, et al. Comparative study of chaga (Inonotus obliquus) dietary supplements using complementary analytical techniques. Int J Mol Sci. 2025. Authors are employed by a company that sells chaga supplements and a testing laboratory, as the paper states. PubMed 40243601. Read 2026-10-23.
- Sweeney LC, Walsh C, O'Cochlain A, Ivory R, Mangan D. Advances in enzymatic measurement of beta-glucan in mushrooms, yeast, algae, and dietary supplements. J AOAC Int. 2026. PubMed 42152188. Read 2026-10-23.
- Keerthana CS, Kumari R, Beura M, et al. Unveiling the glucan profile: a comparative study of Lion's Mane and Shiitake mushrooms. Nat Prod Res. 2026. PubMed 40407020. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Using Dietary Supplements Wisely. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Reishi Mushroom: Purported Benefits, Side Effects & More. Read 2026-10-23.