Drug & supplement interaction

Gumweed + Ambrisentan

Ambrisentan brand names: Letairis, Volibris.

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 Gumweed and Ambrisentan 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

Gumweed and Ambrisentan

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 Ambrisentan and Gumweed 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 Gumweed at all — not against Ambrisentan, 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.

Gumweed safety at a glance

Gumweed overall Use caution Generally used in small amounts traditionally, but human safety data are limited.
Pregnancy Avoid Not enough safety information, so it is best avoided.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use.

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

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

What Gumweed Itself Has Been Linked To

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

  • Diarrhea Additional detail

    “Orally, gumweed seems to be well tolerated. It can cause gastric mucosal irritation (2,12), diarrhea (18), and kidney irritation (12).”

    Gumweed · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    3. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    “Orally, gumweed can cause gastric mucosal irritation (2,12) and diarrhea (18).”

    Gumweed · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    3. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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

Everything else you take

See Every Supplement That Interacts With Ambrisentan

This page covers Gumweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ambrisentan page lists 256 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Beer (major) and Grapefruit (major).

By severity: 9 major · 210 moderate · 37 minor.

Open the Ambrisentan interaction page

One more smart check

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

We hold 18 real supplement products containing Gumweed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Gumweed. Even though Gumweed itself has no known interaction with Ambrisentan, 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 Gumweed and Ambrisentan 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 Gumweed
Steady interest

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

29 days ago today
Medication Ambrisentan
Top half

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

What is Gumweed?

  • Cough and bronchitis
  • Asthma-related breathing problems
  • Skin irritation from poison ivy or poison oak
  • Minor wounds and rashes
  • Upper respiratory congestion

Gumweed is a traditional North American plant used mostly for coughs, chest congestion, and skin irritation such as poison ivy rashes. Good-quality human studies are lacking, so its benefits are not well proven, and it should be used cautiously and avoided during pregnancy and breastfeeding.

Grindelia robusta · Asteraceae · Dried leaves and flowering tops · Tea, tincture, liquid extract, capsules, topical preparations

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

Gumweed: dosing

There is no well-established, standardized dose for gumweed. Traditional preparations include teas, tinctures, and liquid extracts, but the strength of commercial products varies widely.The safest approach is to follow the directions on the product label and not exceed the suggested amount.

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

Read the full Gumweed monograph & all interactions
Medication

About Ambrisentan

What Is Ambrisentan Used For?

Brand names: Letairis, Volibris

Ambrisentan tablets and Letairis tablets are both used to treat pulmonary arterial hypertension (PAH, WHO Group 1) — a condition where the blood pressure in the arteries leading to the lungs is dangerously high. Both are approved to help adults exercise better and slow the worsening of PAH.

Both ambrisentan tablets and Letairis are also approved to be used together with tadalafil (another PAH medicine) to further reduce the risk of disease progression, lower the chance of hospitalization for worsening PAH, and improve exercise ability. Most of the clinical evidence was in patients with mild-to-moderate symptoms and PAH caused by unknown or inherited causes, or PAH linked to connective tissue diseases.

See full Ambrisentan drug information
Keep checking

Other Drugs & Gumweed

Browse every other medication we’ve checked against Gumweed — 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 Gumweed 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 Gumweed list.

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

Gumweed References

The 3 references that drive our Gumweed 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. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Gumweed and Ambrisentan Together: Common Questions

Is it safe to take Gumweed with Ambrisentan?
We do not list a known interaction between Gumweed and Ambrisentan. 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 Ambrisentan interact with any supplements?
Yes. Ambrisentan has documented interactions with 256 supplements in our database — Gumweed is not one of them. The Ambrisentan 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

Gumweed monograph Uses, safety profile, and every drug interaction in one place Ambrisentan drug information The full plain-English guide to this medication Ambrisentan supplement interactions Every supplement checked against Ambrisentan, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Ambrisentan and Gumweed?

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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.