Drug & supplement interaction

Marsh Blazing Star + Ondansetron

Ondansetron brand name: Zofran.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Marsh Blazing Star 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.

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Interaction report

Marsh Blazing Star 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 Marsh Blazing Star 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 Marsh Blazing Star at all — not against Ondansetron, 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.

Marsh Blazing Star safety at a glance

Marsh Blazing Star overall Not established There is not enough reliable human research to judge its safety.
Pregnancy Avoid Avoid because of traditional use affecting menstruation and a lack of safety data.
Breastfeeding Avoid Avoid due to lack of safety information while breastfeeding.

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

Still wondering about combining Ondansetron and Marsh Blazing Star? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Marsh Blazing Star Itself Has Been Linked To

This is not an interaction — nothing below involves Ondansetron. It is the side-effect record for Marsh Blazing Star on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Marsh Blazing Star, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Liver problems / An allergic reaction Worth acting on Additional detail

    “Orally, marsh blazing star, which contains coumarin, can be associated with nausea and vomiting, diarrhea, dizziness, insomnia, asymptomatic SGOT elevations, and liver toxicity (6,18).

    Topically, handling the plant can cause contact dermatitis.

    Marsh blazing star can cause an allergic reaction in individuals sensitive to the Asteraceae/Compositae family.”

    Marsh Blazing Star · Natural Medicines adverse-effect record, reported in dermatitis.

    5 sources cited
    1. 286. Mohler JL, Gomella LG, Crawford ED, et al. Phase II evaluation of coumarin (1,2-benzopyrone) in metastatic prostatic carcinoma. Prostate 1992;20:123-31. PubMed
    2. 287. Marshall ME, Butler K, Fried A. Phase I evaluation of coumarin (1,2 benzopyrone) and cimetidine in patients with advanced malignancies. Mol Biother 1991;3:170-8.
    3. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    4. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    5. 3837. Goerz G, Wirth G, Maas B, et al. [Allergic contact dermatitis due to Asteraceae (Compositae). Cross reaction with Liatris spicata]. Derm Beruf Umwelt 1985;33:95-8.
  • Trouble sleeping / Dizziness / Diarrhea / A skin rash / Vomiting / Nausea Additional detail

    Recorded for Marsh Blazing Star in the same Natural Medicines adverse-effect record shown under Liver problems / An allergic reaction above.

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

From our Q&A

Questions About Marsh Blazing Star 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 Marsh Blazing Star 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 Marsh Blazing Star 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

How much people look this up

Where Marsh Blazing Star 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 Marsh Blazing Star
Steady interest

#1,384 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ondansetron
Steady interest

#2,073 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 Marsh Blazing Star reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Marsh Blazing Star and Ondansetron 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 Marsh Blazing Star

What is Marsh Blazing Star?

Marsh Blazing Star
  • Kidney and urinary complaints
  • Menstrual cramps (dysmenorrhea)
  • As a diuretic
  • Colic and digestive upset
  • Sore throat (traditional gargle)

Marsh blazing star (Liatris spicata) is a North American prairie plant whose root has a long history in folk medicine for urinary, menstrual, and digestive complaints. There is very little modern scientific evidence to confirm that it works or to define a safe dose, so it should be used cautiously and avoided in pregnancy and breastfeeding.

Liatris spicata · Asteraceae · Root · Dried root, tea, tincture, capsules

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

Marsh Blazing Star: dosing

There is no established or standardized dose for marsh blazing star. Traditional preparations used the dried root as a tea or tincture, but no reliable amount has been confirmed as safe or effective in modern research.If you choose to use a commercial product, follow the directions on the label and do not exceed them.

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

Read the full Marsh Blazing Star 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 & Marsh Blazing Star

Browse every other medication we’ve checked against Marsh Blazing Star — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Marsh Blazing Star References

The 5 references that drive our Marsh Blazing Star 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. Mohler JL, Gomella LG, Crawford ED, et al. Phase II evaluation of coumarin (1,2-benzopyrone) in metastatic prostatic carcinoma. Prostate 1992;20:123-31. PubMed
  4. Marshall ME, Butler K, Fried A. Phase I evaluation of coumarin (1,2 benzopyrone) and cimetidine in patients with advanced malignancies. Mol Biother 1991;3:170-8.
  5. Goerz G, Wirth G, Maas B, et al. [Allergic contact dermatitis due to Asteraceae (Compositae). Cross reaction with Liatris spicata]. Derm Beruf Umwelt 1985;33:95-8.

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 Marsh Blazing Star and Ondansetron Together: Common Questions

Is it safe to take Marsh Blazing Star with Ondansetron?
We do not list a known interaction between Marsh Blazing Star 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.
Does Ondansetron interact with any supplements?
Yes. Ondansetron has documented interactions with 195 supplements in our database — Marsh Blazing Star 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 Marsh Blazing Star?

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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.