Drug & supplement interaction

Bergamot + 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 Bergamot 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

Bergamot 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 Bergamot 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.

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.

Bergamot safety at a glance

Bergamot overall Use caution Oral extract appears generally well tolerated short-term, but the essential oil can be toxic if swallowed and can cause sun-related skin reactions.
Pregnancy Possibly Unsafe When the oil is used topically. There is insufficient reliable information available about the safety of bergamot when taken by mouth in medicinal amounts; avoi... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When the oil is used topically. There is insufficient reliable information available about the safety of bergamot when taken by mouth in medicinal amounts; avoi... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Granisetron and Bergamot? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Granisetron

Interactions in our licensed database are recorded against drug classes, not just single drug names. Granisetron is filed under 3 classifications — serotonergic drugs, serotonergic drugs, oral drugs. Bergamot has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (moderate) and photosensitizing drugs (moderate) — and none of Granisetron’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Bergamot Does Interact With Other Medications

Bergamot has 410 moderate known drug interactions in our database — Granisetron isn’t one of them. If you take anything else, check it against the full list below.

Moderate 410 No known interaction 2,420 (incl. Granisetron)
Taking anything else?

Check Another of Your Medications Against Bergamot

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

What to actually watch for

What Bergamot Itself Has Been Linked To

This is not an interaction — nothing below involves Granisetron. It is the side-effect record for Bergamot on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Bergamot, this list is the first place to look.

  • Heartburn Additional detail

    “Orally, bergamot extract has been associated with one case of heartburn in clinical research.”

    Bergamot · Natural Medicines adverse-effect record, reported in dyspepsia.

    1 source cited
    1. 96356. Bruno A, Pandolfo G, Crucitti M, Cedro C, Zoccali RA, Muscatello MRA. Bergamot Polyphenolic Fraction Supplementation Improves Cognitive Functioning in Schizophrenia: Data From an 8-Week, Open-Label Pilot Study. J Clin Psychopharmacol 2017;37(4):468-71. PubMed
  • Sun sensitivity Additional detail

    “Frequent contact with the peel or oil of bergamot can cause erythema, blisters, pustules, dermatoses leading to scab formation, and pigment spots (18).

    Topically, photosensitivity can also occur, especially in fair-skinned people.”

    Bergamot · Natural Medicines adverse-effect record, reported in erythema.

    2 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 11019. Naganuma M, Hirose S, Nakayama Y, et al. A study of the phototoxicity of lemon oil. Arch Dermatol Res 1985;278:31-6. . PubMed
  • Muscle pain Additional detail

    “Orally, muscle cramps have been reported for a patient starting one week after switching from drinking 4 liters of black tea to drinking 4 liters of Earl Grey tea daily. The muscle cramps were attributed bergapten, a constituent of bergamot essential oil in Earl Grey tea.”

    Bergamot · Natural Medicines adverse-effect record, reported in muscle cramps.

    1 source cited
    1. 34344. Finsterer, J. Earl Grey tea intoxication. Lancet 4-27-2002;359(9316):1484. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Bergamot — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Granisetron’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Granisetron column appears here.

Special populations

Bergamot in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When the oil is used topically. There is insufficient reliable information available about the safety of bergamot when taken by mouth in medicinal amounts; avoid use.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

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

At least one FDA label for a product containing Granisetron says to take it on an empty stomach. Most supplements — Bergamot 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 Bergamot 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. See the Granisetron drug page ›

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 Bergamot 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. Bergamot 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.

Bergamot has been studied for:

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

    Bergamot for nausea and vomiting

    It is unclear if inhaled bergamot essential oil is beneficial for nausea and vomiting in children undergoing stem cell transplantation.

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 Bergamot for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Bergamot or Granisetron

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Bergamot or Granisetron, 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 Granisetron

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

We hold 47 real supplement products containing Bergamot, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bergamot. Even though Bergamot itself has no known interaction with Granisetron, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Bergamot 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 Bergamot
Top half

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

29 days ago today
Medication Granisetron
Steady interest

#2,457 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 Bergamot reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Bergamot 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 Bergamot

What is Bergamot?

Bergamot
  • High cholesterol
  • Heart and metabolic health
  • Anxiety and stress (aromatherapy)
  • Antimicrobial/antiseptic
  • Skin care and fragrance

Bergamot is a Mediterranean citrus fruit, and its standardized extract is most often used to support cholesterol and heart health, with some early but promising research. The essential oil is widely used for fragrance and aromatherapy but should not be taken by mouth, and it can make skin more sensitive to sunlight. Talk with your pharmacist or doctor before using bergamot supplements, especially if you take medicine for cholesterol or blood sugar.

Citrus bergamia · Rutaceae · Fruit (juice, peel, and essential oil) and standardized flavonoid extract · Capsules, tablets, essential oil, standardized extract, food and drink flavoring

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

Bergamot: dosing

There is no official, well-established standard dose for bergamot. Supplements are often standardized to a percentage of total flavonoids, and the amount per capsule varies a lot between products.The best approach is to follow the directions on the product label and not exceed the recommended amount. Because product strength and quality differ, choose brands that test for quality and clearly list the standardized flavonoid content.Bergamot essential oil should not be taken by mouth.

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

Read the full Bergamot 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 & Bergamot

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

0Major
410Moderate
0Minor
2,419No known interaction
410 Moderate 2,419 No interaction
Moderate

410 interactions

Showing 60 of 410 moderate interactions — see all 410 on the Bergamot page.

No interaction 2,419 drugs checked — show the list

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

Showing the 60 most looked-up of 2,419 medications checked with no known interaction — see the full Bergamot list.

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

Bergamot References

The 17 references that drive our Bergamot 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Naganuma M, Hirose S, Nakayama Y, et al. A study of the phototoxicity of lemon oil. Arch Dermatol Res 1985;278:31-6. . PubMed
  4. Kaddu, S., Kerl, H., and Wolf, P. Accidental bullous phototoxic reactions to bergamot aromatherapy oil. J.Am.Acad.Dermatol. 2001;45(3):458-461. PubMed
  5. Finsterer, J. Earl Grey tea intoxication. Lancet 4-27-2002;359(9316):1484. PubMed
  6. Gruson, L. M. and Chang, M. W. Berloque dermatitis mimicking child abuse. Arch.Pediatr.Adolesc.Med. 2002;156(11):1091-1093. PubMed
  7. Weisenseel, P. and Woitalla, S. [Toxic mustard plaster dematitis and phototoxic dematitis after application of bergamot oil]. MMW.Fortschr.Med. 12-15-2005;147(51-52):53, 55.
  8. Placzek, M., Fromel, W., Eberlein, B., Gilbertz, K. P., and Przybilla, B. Evaluation of phototoxic properties of fragrances. Acta Derm.Venereol. 2007;87(4):312-316. PubMed
  9. Mollace, V., Sacco, I., Janda, E., Malara, C., Ventrice, D., Colica, C., Visalli, V., Muscoli, S., Ragusa, S., Muscoli, C., Rotiroti, D., and Romeo, F. Hypolipemic and hypoglycaemic activity of bergamot polyphenols: from animal models to human studies. F PubMed
  10. Morliere, P., Huppe, G., Averbeck, D., Young, A. R., Santus, R., and Dubertret, L. In vitro photostability and photosensitizing properties of bergamot oil. Effects of a cinnamate sunscreen. J.Photochem.Photobiol.B 1990;7(2-4):199-208. PubMed
  11. Young, A. R., Walker, S. L., Kinley, J. S., Plastow, S. R., Averbeck, D., Morliere, P., and Dubertret, L. Phototumorigenesis studies of 5-methoxypsoralen in bergamot oil: evaluation and modification of risk of human use in an albino mouse skin model. J.P PubMed
  12. Girard, J., Unkovic, J., Delahayes, J., and Lafille, C. [Phototoxicity of Bergamot oil. Comparison between humans and guinea pigs]. Dermatologica 1979;158(4):229-243.
  13. Zaynoun, S. T., Johnson, B. E., and Frain-Bell, W. A study of oil of bergamot and its importance as a phototoxic agent. II. Factors which affect the phototoxic reaction induced by bergamot oil and psoralen derivatives. Contact Dermatitis 1977;3(5):225-23 PubMed
  14. Zacher, K. D. and Ippen, H. [Contact dermatitis caused by bergamot oil]. Derm.Beruf.Umwelt. 1984;32(3):95-97.
  15. Yasui, Y. and Hirone, T. Action spectrum for bergamot-oil phototoxicity measured by sunburn cell counting. J.Dermatol. 1994;21(5):319-322. PubMed

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 Bergamot and Granisetron Together: Common Questions

Is it safe to take Bergamot with Granisetron?
We do not list a known interaction between Bergamot 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 Bergamot 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 Bergamot 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 Bergamot 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 Bergamot in each. That is a conversation for your prescriber, especially if Granisetron is being adjusted to a target.
How was the Bergamot and Granisetron combination checked?
Interactions in our licensed database are recorded against drug classes. Granisetron is filed under 3 classifications, and Bergamot has documented interactions with 2 drug classes — none of Granisetron's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Bergamot interact with any other medications?
Yes. Bergamot has 410 documented drug interactions in our database — Granisetron is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Granisetron interact with any supplements?
Yes. Granisetron has documented interactions with 38 supplements in our database — Bergamot 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

Bergamot 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 17 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Granisetron and Bergamot?

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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.