Drug & supplement interaction

Beta-glucans + Fostamatinib

Fostamatinib brand name: Tavalisse.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Beta-glucans has a moderate interaction with Fostamatinib. Theoretically, beta-glucans might interfere with immunosuppressive therapy.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Beta-glucans and Fostamatinib

Here is the interaction we found between these two, with the evidence behind it.

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Fostamatinib

Fostamatinib falls under IMMUNOSUPPRESSANTS — the group Beta-glucans interacts with.

Theoretically, beta-glucans might interfere with immunosuppressive therapy.
Some clinical research shows that beta-glucans have immunostimulant effects.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the idea behind this one. Some lab and animal research suggests beta-glucans (especially the yeast and mushroom types) may give the immune system a little nudge. Fostamatinib works in the opposite direction. It's actually a prodrug, meaning your body converts it into an active form (R406) that calms down an overactive immune response so your platelets aren't destroyed as quickly. So in theory, a supplement that revs the immune system up could work against what the medicine is trying to do.

I want to be straight with you though: this is a theoretical concern based on weak, mostly lab evidence, not real-world cases in people on Fostamatinib. Oat and barley fiber in food is very unlikely to matter. Before starting any concentrated immune-support beta-glucan supplement, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Bergendiova, K., Tibenska, E., and Majtan, J. Pleuran (beta-glucan from Pleurotus ostreatus) supplementation, cellular immune response and respiratory tract infections in athletes. Eur.J.Appl.Physiol 2011;111(9):2033-2040.
  2. Talbott S, Talbott J. Effect of beta 1,3/1,6 glucan on respiratory tract infection symptoms and mood state in marathon athletes. J Sports Sci Med 2009;8(4):509-515.
  3. Feldman S, Schwartz HI Kalman DS Mayers A Kohrman HM Clemens R Krieger DR. Randomized phase II clinical trials of Wellmune WGP® for immune support during cold and flu season. The Journal of Applied Research 2009;9(1-2):30-42.
  4. McFarlin BK, Carpenter KC, Davidson T, McFarlin MA. Baker's yeast beta glucan supplementation increases salivary IgA and decreases cold/flu symptomatic days after intense exercise. J Diet Suppl. 2013;10(3):171-83. PubMed
  5. Mah E, Kaden VN, Kelley KM, Liska DJ. Beverage containing dispersible yeast ß-glucan decreases cold/flu symptomatic days after intense exercise: a randomized controlled trial. J Diet Suppl 2020;17(2):200-10. PubMed
  6. Zhong K, Liu Z, Lu Y, Xu X. Effects of yeast ß-glucans for the prevention and treatment of upper respiratory tract infection in healthy subjects: a systematic review and meta-analysis. Eur J Nutr. 2021. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Beta-glucans Also Interacts With Other Medications

Beta-glucans has 292 moderate known drug interactions in our database — the Fostamatinib one above is one of them. If you take anything else, check it against the full list below.

Moderate 292 No known interaction 2,538 (incl. Fostamatinib)
Taking anything else?

Check Another of Your Medications Against Beta-glucans

Covers the 2,830 medications we’ve checked against Beta-glucans. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Fostamatinib

This page covers Beta-glucans only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fostamatinib page lists 209 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 167 moderate · 36 minor.

From our pharmacist’s overview on the Fostamatinib page

“I would treat the supplement list for fostamatinib (Tavalisse), a medicine that raises platelet counts in chronic immune thrombocytopenia, with real care. Most of what shows up here involves CYP3A4, the liver enzyme that clears fostamatinib, so grapefruit can drive its blood level up while St.”

Reviewed by 2 · Jul 18, 2026

Open the Fostamatinib interaction page

One more smart check

Taking Beta-glucans as Part of a Dietary Supplement Product? Check It for Interactions

We hold 809 real supplement products containing Beta-glucans, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Beta-glucans. Your product may carry other ingredients that interact with Fostamatinib too, on top of Beta-glucans — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Beta-glucans and Fostamatinib Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Beta-glucans
Top 25%

#252 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Fostamatinib
Steady interest

#1,699 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Beta-glucans

What is Beta-glucans?

  • High cholesterol
  • Heart health
  • Immune support
  • Blood sugar control
  • Wound care (topical)

Beta-glucans are natural fibers found in oats, barley, mushrooms, and yeast. The strongest evidence supports the oat and barley types for modestly lowering cholesterol and blood sugar, while immune-related claims from yeast and mushroom sources are far less proven. They are generally well tolerated, but check with your pharmacist before starting any supplement.

Read the full Beta-glucans monograph & all interactions
Medication

About Fostamatinib

What Is Fostamatinib Used For?

Brand name: Tavalisse

Tavalisse (fostamatinib) is used to treat thrombocytopenia — dangerously low platelet counts — in adults with chronic immune thrombocytopenia (ITP). It is specifically for people whose platelet counts have not improved enough with at least one earlier ITP treatment.

The goal is to raise platelet counts high enough to reduce the risk of serious bleeding. If platelet counts do not respond sufficiently after 12 weeks, the medication is typically stopped.

See full Fostamatinib drug information
Keep checking

Other Drugs & Beta-glucans

Browse every other medication we’ve checked against Beta-glucans — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
292Moderate
0Minor
2,537No known interaction
292 Moderate 2,537 No interaction
Moderate

292 interactions

Showing 60 of 292 moderate interactions — see all 292 on the Beta-glucans page.

No interaction 2,537 drugs checked — show the list

We also checked Beta-glucans against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,537 medications checked with no known interaction — see the full Beta-glucans list.

See the full Beta-glucans interactions page
See every supplement checked against Fostamatinib, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Beta-glucans monograph › Uses, safety, and every drug interaction in one place Fostamatinib supplement interactions › Every supplement checked against Fostamatinib, ranked by severity Fostamatinib drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Beta-glucans and Fostamatinib Together: Common Questions

Can you take Beta-glucans with Fostamatinib?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Beta-glucans and Fostamatinib interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Fostamatinib and Beta-glucans?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.