Drug & supplement interaction

European Chestnut + Granisetron

Granisetron brand names: Kytril, Sustol.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between European Chestnut and Granisetron in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Granisetron states a food rule worth keeping to.

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Interaction report

European Chestnut and Granisetron

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Granisetron and European Chestnut in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for European Chestnut at all — not against Granisetron, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

European Chestnut safety at a glance

European Chestnut overall Use caution The nut is a common food, but concentrated leaf or bark extracts have not been well studied for safety.
Pregnancy Avoid There is not enough safety information, so medicinal use during pregnancy is best avoided.
Breastfeeding Avoid Safety during breastfeeding is unknown, so medicinal use is best avoided.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Granisetron and European Chestnut? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Granisetron’s Own FDA Label Lists

This is not an interaction — none of it involves European Chestnut. These are the most notable effects listed in the ADVERSE REACTIONS section of Granisetron’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 7 of them are worth acting on rather than waiting out — marked below.

  • A slow heartbeat Worth acting on
  • An irregular heartbeat Worth acting on
  • Raised blood pressure Worth acting on
  • Shortness of breath Worth acting on
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on
  • An allergic reaction Worth acting on
  • A change in taste
  • A fast or pounding heartbeat
  • Low blood pressure

Showing the 10 most notable of 21 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Granisetron. Read the label on DailyMed › European Chestnut’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no European Chestnut side to compare — that is a limit of the record, not a statement that European Chestnut has no side effects.

How to take them

Some Granisetron Products Have a Food Rule — European Chestnut Should Not Break It

At least one FDA label for a product containing Granisetron says to take it on an empty stomach. Most supplements — European Chestnut included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Granisetron on its own and move European Chestnut to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Granisetron products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Recommended Dosage ( 2.2 ): The recommended dosage in adults is 10 mg administered as a single subcutaneous injection at least 30 minutes before the start of emetogenic chemotherapy on Day 1.

From the Dosage and Administration section of the FDA label we read for Granisetron — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Granisetron Is Prescribed For, and What European Chestnut Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Granisetron is a prescription medicine with approved uses on its FDA label. European Chestnut is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Granisetron is prescribed for: 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.

Read the rest of what Granisetron is prescribed for

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.

European Chestnut has been studied for:

  • Nausea and vomiting studied, not established European Chestnut has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    European Chestnut for nausea and vomiting

    Although there is interest in using oral European chestnut for nausea and vomiting, there is insufficient reliable information about the clinical effects of European chestnut for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Granisetron on your own; if you are taking European Chestnut for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Granisetron

This page covers European Chestnut 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

How much people look this up

Where European Chestnut 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 European Chestnut
Steady interest

#1,420 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Granisetron
Steady interest

#1,947 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every European Chestnut reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The European Chestnut and Granisetron records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About European Chestnut

What is European Chestnut?

  • Coughs and respiratory irritation
  • Diarrhea and digestive upset
  • Sore throat
  • Wound and skin care
  • General antioxidant support

European Chestnut is a tree whose leaves and nuts have a long history of use for coughs, diarrhea, and skin care, mostly in traditional folk medicine. High-quality human studies are lacking, so its benefits remain unproven, and it should be used cautiously and discussed with a pharmacist or doctor.

Castanea sativa · Fagaceae · Leaves, nuts (seeds), bark, and flowers · Tea, liquid extract, capsules, honey, and topical preparations

An interaction check asks whether these two react with each other — it does not ask whether European Chestnut is a good idea for someone in your situation. Here is what our European Chestnut record says about it on its own.

European Chestnut: dosing

There is no standardized or well-established medicinal dose for European Chestnut. Products vary widely in strength and in which part of the plant they use.If you choose to use a chestnut product, follow the directions on the label and do not exceed the recommended amount.

From our European Chestnut monograph — the full record covers uses, side effects and every documented interaction.

Read the full European Chestnut 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 & European Chestnut

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full European Chestnut list.

See the full European Chestnut interactions page
See every supplement checked against Granisetron, ranked by severity
Evidence & sources

European Chestnut References

The 1 references that drive our European Chestnut monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking European Chestnut and Granisetron Together: Common Questions

Is it safe to take European Chestnut with Granisetron?
We do not list a known interaction between European Chestnut and Granisetron. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take European Chestnut and Granisetron at the same time of day?
At least one FDA label for a product containing Granisetron says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Granisetron on its own and move European Chestnut to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
Are European Chestnut and Granisetron used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for European Chestnut in each. That is a conversation for your prescriber, especially if Granisetron is being adjusted to a target.
Does Granisetron interact with any supplements?
Yes. Granisetron has documented interactions with 38 supplements in our database — European Chestnut is not one of them. The Granisetron interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

European Chestnut monograph Uses, safety profile, and every drug interaction in one place Granisetron drug information The full plain-English guide to this medication Granisetron supplement interactions Every supplement checked against Granisetron, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Granisetron and European Chestnut?

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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.