Drug & supplement interaction

Tragacanth + Granisetron

Granisetron brand names: Kytril, Sustol.

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

Tragacanth has a moderate interaction with Granisetron. Theoretically, tragacanth might alter absorption of oral drugs.

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

Tragacanth and Granisetron

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

Moderate

ORAL DRUGS

Why this applies to Granisetron

Granisetron falls under ORAL DRUGS — the group Tragacanth interacts with.

Theoretically, tragacanth might alter absorption of oral drugs.
Tragacanth contains hydrocolloidal fiber which can decrease, increase, or not affect oral drug absorption. To avoid changes in absorption, take tragacanth 30-60 minutes after oral medications.
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 situation with these two. Tragacanth is basically a fiber gum that swells into a thick gel in your stomach. When you take an oral medicine like granisetron tablets at the same time, that gel can theoretically grab onto the drug and change how much of it gets absorbed. It could lower absorption, which might mean your nausea protection isn't as strong, or in some cases it might not matter at all.

I want to be honest: this is a theoretical concern based on how the gum behaves, not something proven to cause problems in people. To stay on the safe side, a simple gap helps. Take your granisetron first, then wait about 30 to 60 minutes before the tragacanth. If you're getting granisetron for chemo nausea, definitely run this by your pharmacist or oncology team first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Tragacanth Also Interacts With Other Medications

Tragacanth has 2,021 moderate known drug interactions in our database — the Granisetron one above is one of them. If you take anything else, check it against the full list below.

Moderate 2,021 No known interaction 809 (incl. Granisetron)
Taking anything else?

Check Another of Your Medications Against Tragacanth

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

Everything else you take

See Every Supplement That Interacts With Granisetron

This page covers Tragacanth only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Granisetron page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 5-htp (moderate), Acetyl-l-carnitine (moderate) and Ayahuasca (moderate).

By severity: 2 major · 25 moderate · 11 minor.

From our pharmacist’s overview on the Granisetron page

“Granisetron (Kytril, Sustol) blocks serotonin signals to stop nausea from chemotherapy and surgery, and this is a list that warrants real caution before you add a supplement to it. Most of the entries raise serotonin themselves, and stacking them on a serotonin-acting drug can push toward serotonin syndrome, a dangerous overload of tha…”

Reviewed by 2 · Jul 18, 2026

Open the Granisetron interaction page

One more smart check

Taking Tragacanth as Part of a Dietary Supplement Product? Check It for Interactions

We hold 34 real supplement products containing Tragacanth, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Tragacanth. Your product may carry other ingredients that interact with Granisetron too, on top of Tragacanth — 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 Tragacanth and Granisetron 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 Tragacanth
Top half

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

29 days ago today
Medication Granisetron
Steady interest

#2,569 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 Tragacanth

What is Tragacanth?

Tragacanth
  • Soothing sore throat and cough
  • Digestive upset and constipation
  • Thickening or binding agent in products
  • Skin soothing in creams and pastes

Tragacanth is a plant gum used mainly as a thickener and emulsifier in foods, cosmetics, and medicines, and traditionally to soothe the throat and gut. There is very little solid human research showing it treats any specific condition. It is generally considered safe in food amounts, but anyone with allergies or who is pregnant or breastfeeding should check with a pharmacist or doctor first.

Read the full Tragacanth monograph & all interactions
Medication

About Granisetron

What Is Granisetron Used For?

Brand names: Kytril, Sustol

Granisetron is used to prevent nausea and vomiting linked to emetogenic (nausea-causing) cancer chemotherapy — including high-dose cisplatin — and radiation therapy, including total body irradiation and fractionated abdominal radiation. Granisetron hydrochloride tablets and Granisol oral solution are approved for both the chemotherapy and radiation indications. Sancuso skin patch is approved for prevention of nausea and vomiting in adults receiving moderately and/or highly emetogenic chemotherapy regimens of up to 5 consecutive days.

Granisetron hydrochloride injection (intravenous) is also used to prevent and treat postoperative nausea and vomiting in adults. Sustol (subcutaneous injection) is used in combination with other anti-nausea medicines in adults specifically for the prevention of acute and delayed nausea and vomiting associated with moderately emetogenic chemotherapy or anthracycline and cyclophosphamide combination chemotherapy regimens.

See full Granisetron drug information
Keep checking

Other Drugs & Tragacanth

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

0Major
2,021Moderate
0Minor
808No known interaction
2,021 Moderate 808 No interaction
Moderate

2,021 interactions

Showing 60 of 2,021 moderate interactions — see all 2,021 on the Tragacanth page.

No interaction 808 drugs checked — show the list

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

Showing the 60 most looked-up of 808 medications checked with no known interaction — see the full Tragacanth list.

See the full Tragacanth interactions page
See every supplement checked against Granisetron, 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
Tragacanth monograph › Uses, safety, and every drug interaction in one place Granisetron supplement interactions › Every supplement checked against Granisetron, ranked by severity Granisetron 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 Tragacanth and Granisetron Together: Common Questions

Can you take Tragacanth with Granisetron?
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 Tragacanth and Granisetron 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 Granisetron and Tragacanth?

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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.