Drug & supplement interaction

Squill + Ondansetron

Ondansetron brand name: Zofran.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Squill and Ondansetron 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 two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Squill and Ondansetron

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 Ondansetron and Squill 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.

Squill safety at a glance

Squill overall Use caution Squill contains heart-active glycosides that can be toxic, so it should only be used under medical supervision.
Pregnancy Unsafe When used orally because it can have an abortifacient effect. Read the full pregnancy detail
Breastfeeding Unsafe When used orally. 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 Ondansetron and Squill? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Ondansetron

Interactions in our licensed database are recorded against drug classes, not just single drug names. Ondansetron is filed under 7 classifications — including serotonergic drugs, serotonergic drugs, cytochrome p450 1a2 (cyp1a2) substrates. Squill has documented interactions with 7 drug classes — the most serious being digoxin (lanoxin) (major), corticosteroids (moderate) and diuretic drugs (moderate) — and none of Ondansetron’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

Squill Does Interact With Other Medications

Squill has 1 major, 155 moderate known drug interactions in our database — Ondansetron isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Squill

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

What to actually watch for

No Interaction Found — But Data Suggests Squill and Ondansetron May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • An irregular heartbeat Worth acting on Additional detail

    Squill

    “Orally, squill can cause irregular pulse (18,94852).

    Squill poisoning resembles digoxin poisoning. The cardiovascular symptoms of squill poisoning include cardiac arrest and life-threatening arrhythmias, including ventricular tachycardia, atrial tachycardia with atrioventricular block, and ventricular fibrillation (18,3488).”

    Squill · Natural Medicines adverse-effect record, reported in arrhythmia.

    3 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 94852. Nejatbakhsh F, Karegar-Borzi H, Amin G, et al. Squill Oxymel, a traditional formulation from Drimia Maritima (L.) Stearn, as an add-on treatment in patients with moderate to severe persistent asthma: A pilot, triple-blind, randomized clinical trial. J Eth PubMed
    3. 3488. Tuncok Y, Kozan O, Cavdar C, et al. Urginea maritima (squill) toxicity. J Toxicol Clin Toxicol 1995;33:83-6.

    Ondansetron

    Listed in the ADVERSE REACTIONS section of the FDA label for Ondansetron. Read the label on DailyMed ›

  • A fast or pounding heartbeat Additional detail

    Squill

    Recorded for Squill in the same Natural Medicines adverse-effect record shown under An irregular heartbeat above.

    Ondansetron

    Listed in the ADVERSE REACTIONS section of the FDA label for Ondansetron. Read the label on DailyMed ›

Reported for Squill but not commonly for Ondansetron: stomach upset, reduced appetite, hallucinations and anxiety or restlessness.

Effects for Ondansetron come from the ADVERSE REACTIONS section of its FDA label; effects for Squill come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 121,840 voluntary FDA FAERS reports for Ondansetron that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Squill in Pregnancy & Breastfeeding

Pregnancy Unsafe

When used orally because it can have an abortifacient effect.

Lactation Unsafe

When used orally.

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

From our Q&A

Questions About Squill or Ondansetron

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

This page covers Squill only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ondansetron page lists 195 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 4 major · 145 moderate · 46 minor.

From our pharmacist’s overview on the Ondansetron page

“Ondansetron (Zofran) often stands between you and relentless nausea from chemotherapy or surgery, so read this page carefully. Four of the 195 ingredients rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Ondansetron interaction page

One more smart check

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

We hold 2 real supplement products containing Squill, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Squill. Even though Squill itself has no known interaction with Ondansetron, 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 Squill and Ondansetron 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 Squill
Steady interest

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

29 days ago today
Medication Ondansetron
Top half

#1,381 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 Squill reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Squill and Ondansetron records this page draws on were last updated July 11, 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 Squill

What is Squill?

Squill
  • Cough and chest congestion
  • Fluid retention (diuretic)
  • Heart conditions (traditional 'cardiac tonic')
  • Hair loss (topical use)
  • Rodenticide (red squill, non-medicinal)

Squill is a bulb plant that contains potent cardiac glycosides, which can affect the heart much like the drug digoxin. While it has a long history of use as a cough remedy and heart tonic, it can be dangerously toxic and there is little solid evidence for its modern use, so we do not recommend taking it without close medical supervision.

Drimia maritima · Asparagaceae · Dried inner bulb scales · Dried bulb, tinctures, liquid extracts, syrups, and some traditional cough preparations

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

Squill: dosing

There is no well-established, standardized safe dose of squill for general use. Because the active compounds are so potent and the toxic dose is close to any possibly effective dose, self-dosing is not recommended.If a product contains squill, follow the label exactly and do not take more than directed.

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

Read the full Squill monograph & all interactions
Medication

About Ondansetron

What Is Ondansetron Used For?

Brand name: Zofran

Ondansetron is used to prevent nausea and vomiting in several situations. Oral forms (tablets, orally disintegrating tablets, and oral solution) are approved to prevent nausea and vomiting from highly or moderately emetogenic (nausea-causing) cancer chemotherapy, from radiation therapy to the abdomen or whole body, and from surgery.

Ondansetron injection (given intravenously or intramuscularly in a clinical setting) is approved to prevent nausea and vomiting from emetogenic cancer chemotherapy — including high-dose cisplatin — in adults and children as young as 6 months old, as well as to prevent postoperative nausea and vomiting.

Most-Reported Side Effects for Ondansetron

From FAERS, the FDA’s public side-effect reporting system (121,840 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Nausea 14,459 reports
Fatigue 10,275 reports
Diarrhea 9,488 reports
Vomiting 8,777 reports
Dyspnea 5,971 reports
See full Ondansetron drug information
Keep checking

Other Drugs & Squill

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

1Major
155Moderate
0Minor
2,673No known interaction
Major

1 interaction

Moderate

155 interactions

Showing 60 of 155 moderate interactions — see all 155 on the Squill page.

No interaction 2,673 drugs checked — show the list
Evidence & sources

Squill References

The 9 references that drive our Squill 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  3. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  4. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  5. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  6. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  7. Tuncok Y, Kozan O, Cavdar C, et al. Urginea maritima (squill) toxicity. J Toxicol Clin Toxicol 1995;33:83-6.
  8. Nejatbakhsh F, Karegar-Borzi H, Amin G, et al. Squill Oxymel, a traditional formulation from Drimia Maritima (L.) Stearn, as an add-on treatment in patients with moderate to severe persistent asthma: A pilot, triple-blind, randomized clinical trial. J Eth PubMed
  9. Moosavi ZB, Aliabdi M, Golfakhrabadi F, Namjoyan F. The comparison of therapeutic effect of Clobetasol propionate lotion and squill extract in alopecia areata: a randomized, double-blind clinical trial. Arch Dermatol Res. 2020 Apr;312(3):173-178. 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 Squill and Ondansetron Together: Common Questions

Is it safe to take Squill with Ondansetron?
We do not list a known interaction between Squill and Ondansetron. 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.
Do Squill and Ondansetron have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Squill and Ondansetron combination checked?
Interactions in our licensed database are recorded against drug classes. Ondansetron is filed under 7 classifications, and Squill has documented interactions with 7 drug classes — none of Ondansetron'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 Squill interact with any other medications?
Yes. Squill has 156 documented drug interactions in our database — Ondansetron 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 Ondansetron interact with any supplements?
Yes. Ondansetron has documented interactions with 195 supplements in our database — Squill is not one of them. The Ondansetron interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Ondansetron and Squill?

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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.