Drug & supplement interaction

Eleuthero + Fostamatinib

Fostamatinib brand name: Tavalisse.

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

Fostamatinib falls into 2 drug categories that Eleuthero can interact with; the most serious is rated moderate. Theoretically, eleuthero might interfere with immunosuppressive drugs because of its immunostimulant activity.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Eleuthero and Fostamatinib

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Eleuthero interacts with whole categories of medication. Fostamatinib falls into 2 of those categories, so it can interact with Eleuthero in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

IMMUNOSUPPRESSANTS

1 of 2

Why this applies to Fostamatinib

Fostamatinib falls under IMMUNOSUPPRESSANTS — the group Eleuthero interacts with.

Theoretically, eleuthero might interfere with immunosuppressive drugs because of its immunostimulant activity.
Animal and in vitro research shows that eleuthero extracts have immunomodulatory effects, including increasing cellular and humoral activity.
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 gist for Tavalisse (fostamatinib). This medicine works partly by calming down immune-driven destruction of your platelets, so it has an immune-quieting role. Eleuthero, on the other hand, has been studied as an immune stimulant. In theory, those two pull in opposite directions, and eleuthero could blunt some of the benefit you're hoping to get from fostamatinib (meaning your platelet counts might not come up as well as expected).

I want to be honest about how solid this is: it's a theoretical concern based mostly on lab and animal studies, not real-world cases in people. So don't panic. Still, since fostamatinib treats a serious bleeding condition, it's worth a quick chat with your doctor or pharmacist before adding eleuthero. Don't start or stop anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Schmolz, M. W., Sacher, F., and Aicher, B. The synthesis of Rantes, G-CSF, IL-4, IL-5, IL-6, IL-12 and IL-13 in human whole-blood cultures is modulated by an extract from Eleutherococcus senticosus L. roots. Phytother.Res 2001;15(3):268-270.
  2. Huang, D. B., Ran, R. Z., and Yu, Z. F. [Effect of Acanthopanax senticosus injection on the activities of human tumor necrosis factor and natural killer cell in blood in the patients with lung cancer]. Zhongguo Zhong.Yao Za Zhi. 2005;30(8):621-624.
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Fostamatinib also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, eleuthero might increase levels of drugs metabolized by CYP3A4.
In vitro and animal research suggest that standardized extracts of eleuthero might inhibit CYP3A4. However, research in healthy human volunteers has found that taking eleuthero 485 mg twice daily for 14 days does not inhibit CYP3A4 drug metabolism.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the gist for Tavalisse (fostamatinib). Your body turns it into its active form, and that active piece is cleared in part by a liver enzyme called CYP3A4. The theory is that eleuthero could slow that enzyme down, which would let more of the drug build up. If that happened, you might notice more of fostamatinib's usual side effects, like high blood pressure, diarrhea, nausea, or liver test changes.

The good news is that this concern is mostly theoretical. It comes from lab and animal studies, but a study in healthy people taking eleuthero twice daily for two weeks did not actually show this effect. So a real-world problem is unlikely. Still, it's worth a quick chat with your pharmacist or doctor before adding eleuthero.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Harkey MR, Henderson GL, Zhou L, et al. Effects of Siberian ginseng (Eleutherococcus senticosus) on c-DNA-expressed P450 drug metabolizing enzymes. Alt Ther 2001;7:S14.
  2. Donovan JL, DeVane CL, Chavin KD, et al. Siberian Ginseng (Eleutheroccus senticosus) Effects on CYP2D6 and CYP3A4 Activity in Normal Volunteers. Drug Metab Dispos 2003;31:519-22.. 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

Eleuthero Also Interacts With Other Medications

Eleuthero has 678 moderate, 461 minor known drug interactions in our database — the Fostamatinib one above is among them. If you take anything else, check it against the full list below.

Moderate 678 Minor 461 No known interaction 1,691 (incl. Fostamatinib)
Taking anything else?

Check Another of Your Medications Against Eleuthero

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

From our Q&A

Questions About Eleuthero or Fostamatinib

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Eleuthero or Fostamatinib, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Fostamatinib

This page covers Eleuthero 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 Eleuthero as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3,795 real supplement products containing Eleuthero, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Eleuthero. Your product may carry other ingredients that interact with Fostamatinib too, on top of Eleuthero — 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 Eleuthero 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 Eleuthero
Top 5%

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

29 days ago today
Medication Fostamatinib
Steady interest

#1,802 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 Eleuthero

What is Eleuthero?

Eleuthero
  • Fatigue and low energy
  • Physical and athletic performance
  • Stress resistance (adaptogen)
  • Immune support
  • Mental focus and alertness

Eleuthero is an herb traditionally used as an 'adaptogen' to fight fatigue, boost energy, and help the body handle stress. The scientific evidence behind these uses is limited and mixed, so it should not replace proven treatments. It is generally well tolerated short-term, but pregnant and breastfeeding people and those with certain conditions should avoid it or check with a healthcare provider first.

Read the full Eleuthero 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 & Eleuthero

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

0Major
678Moderate
461Minor
1,690No known interaction
678 Moderate 461 Minor 1,690 No interaction
Moderate

678 interactions

Showing 60 of 678 moderate interactions — see all 678 on the Eleuthero page.

Minor

461 interactions

Showing 60 of 461 minor interactions — see all 461 on the Eleuthero page.

No interaction 1,690 drugs checked — show the list

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

Showing the 60 most looked-up of 1,690 medications checked with no known interaction — see the full Eleuthero list.

See the full Eleuthero 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
Eleuthero 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 Eleuthero and Fostamatinib Together: Common Questions

Can you take Eleuthero 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.
Why are there 2 interactions listed for Eleuthero and Fostamatinib?
Fostamatinib belongs to more than one drug category, and Eleuthero interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Eleuthero 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 Eleuthero?

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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.