Drug & supplement interaction

Rusty-leaved Rhododendron + Regorafenib

Regorafenib brand name: Stivarga.

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 Rusty-leaved Rhododendron and Regorafenib 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

Rusty-leaved Rhododendron and Regorafenib

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 Regorafenib and Rusty-leaved Rhododendron 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 Rusty-leaved Rhododendron at all — not against Regorafenib, 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.

Rusty-leaved Rhododendron safety at a glance

Rusty-leaved Rhodo... overall Use caution Limited safety data and risk of toxic look-alike species mean it should be used cautiously.
Pregnancy Possibly Unsafe When used orally. Rusty-leaved rhododendron might be poisonous; avoid using. Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. Rusty-leaved rhododendron might be poisonous; avoid using. 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 Regorafenib and Rusty-leaved Rhododendron? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Rusty-leaved Rhododendron and Regorafenib May Share a Side Effect

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.

  • Nausea Additional detail

    Rusty-leaved Rhododendron

    “There is currently no information on the adverse effects of rusty-leaved rhododendron. A related species, Rhododendron ponticum, can cause weakness, dizziness, nausea, vomiting, hypotension, bradycardia, transient A-V dissociation and blurred vision (18,3496).”

    Rusty-leaved Rhododendron · Natural Medicines adverse-effect record, reported in epilepsy.

    5 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 3496. Biberoglu S, Biberoglu K, Komsuoglu B. Mad honey. [Letter to the Editor] JAMA 1988;259:1943.
    3. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    4. 3477. Furbee B, Wermuth M. Life-threatening plant poisoning. Crit Care Clin 1997;13:849-88. PubMed
    5. 100643. Louis A, Petereit F, Lechtenberg M, Deters A, Hensel A. Phytochemical characterization of Rhododendron ferrugineum and in vitro assessment of an aqueous extract on cell toxicity. Planta Med 2010;76(14):1550-7. doi: 10.1055/s-0029-1241016.

    Regorafenib

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

Reported for Rusty-leaved Rhododendron but not commonly for Regorafenib: blurred vision, a slow heartbeat, low blood pressure and dizziness.

Effects for Regorafenib come from the ADVERSE REACTIONS section of its FDA label; effects for Rusty-leaved Rhododendron come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 11,442 voluntary FDA FAERS reports for Regorafenib 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

Rusty-leaved Rhododendron in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. Rusty-leaved rhododendron might be poisonous; avoid using.

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

Everything else you take

See Every Supplement That Interacts With Regorafenib

This page covers Rusty-leaved Rhododendron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Regorafenib page lists 138 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 94 moderate · 41 minor.

From our pharmacist’s overview on the Regorafenib page

“Regorafenib (Stivarga) is a targeted oral cancer therapy, and with a drug like this the goal is keeping its blood level inside a fairly tight window, so the 138 supplements and herbs on this page deserve real respect. Nearly all of them, 121 in total, can shift how the liver enzyme CYP3A4 processes the drug, nudging its level up or down.”

Reviewed by 2 · Jul 18, 2026

Open the Regorafenib interaction page

How much people look this up

Where Rusty-leaved Rhododendron and Regorafenib 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 Rusty-leaved Rhododendron
Steady interest

#1,424 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Regorafenib
Top half

#832 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 Rusty-leaved Rhododendron reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Rusty-leaved Rhododendron and Regorafenib 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 Rusty-leaved Rhododendron

What is Rusty-leaved Rhododendron?

  • Joint and muscle pain
  • Gout and rheumatic complaints
  • High blood pressure (folk use)
  • General aches and pains

Rusty-leaved rhododendron is an alpine shrub used in traditional European medicine for pain and rheumatic complaints, but there is very little human research to support these uses. Because rhododendron species can contain toxic compounds and are easily confused with one another, it is best to use this plant only with professional guidance and to avoid it during pregnancy and breastfeeding.

Rhododendron ferrugineum · Ericaceae · Leaves and flowers · Tea, tincture, dried herb, topical preparations

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

Rusty-leaved Rhododendron: dosing

There is no established or standardized safe dose for rusty-leaved rhododendron. Because the plant can contain toxic compounds and because amounts vary from plant to plant, it is not possible to recommend a specific dose.If you choose to use a commercial product, follow the directions on the label and do not exceed them.

From our Rusty-leaved Rhododendron monograph — the full record covers uses, side effects and every documented interaction.

Read the full Rusty-leaved Rhododendron monograph & all interactions
Medication

About Regorafenib

What Is Regorafenib Used For?

Brand name: Stivarga

Stivarga is approved to treat three types of advanced cancer in adults. It is used for metastatic colorectal cancer (cancer that has spread) after prior chemotherapy and targeted therapy; for locally advanced, unresectable, or metastatic gastrointestinal stromal tumor (GIST) after two previous treatments; and for hepatocellular carcinoma (liver cancer) after treatment with sorafenib.

All three uses are specific to Stivarga tablets taken by mouth. It is intended for patients whose cancer has progressed despite earlier lines of therapy.

Most-Reported Side Effects for Regorafenib

From FAERS, the FDA’s public side-effect reporting system (11,542 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 1,769 reports
Palmar-plantar erythrodysaesthesia syndrome 1,439 reports
Diarrhea 1,418 reports
Decreased appetite 1,091 reports
Asthenia 946 reports
See full Regorafenib drug information
Keep checking

Other Drugs & Rusty-leaved Rhododendron

Browse every other medication we’ve checked against Rusty-leaved Rhododendron — 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 Rusty-leaved Rhododendron 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 Rusty-leaved Rhododendron list.

See the full Rusty-leaved Rhododendron interactions page
See every supplement checked against Regorafenib, ranked by severity
Evidence & sources

Rusty-leaved Rhododendron References

The 6 references that drive our Rusty-leaved Rhododendron 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. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. Terry C. Telger, transl. 3rd ed. Berlin, GER: Springer, 1998.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  4. Furbee B, Wermuth M. Life-threatening plant poisoning. Crit Care Clin 1997;13:849-88. PubMed
  5. Biberoglu S, Biberoglu K, Komsuoglu B. Mad honey. [Letter to the Editor] JAMA 1988;259:1943.
  6. Louis A, Petereit F, Lechtenberg M, Deters A, Hensel A. Phytochemical characterization of Rhododendron ferrugineum and in vitro assessment of an aqueous extract on cell toxicity. Planta Med 2010;76(14):1550-7. doi: 10.1055/s-0029-1241016.

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 Rusty-leaved Rhododendron and Regorafenib Together: Common Questions

Is it safe to take Rusty-leaved Rhododendron with Regorafenib?
We do not list a known interaction between Rusty-leaved Rhododendron and Regorafenib. 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 Rusty-leaved Rhododendron and Regorafenib have any of the same side effects?
Yes — our sources link each of them separately to one 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.
Does Regorafenib interact with any supplements?
Yes. Regorafenib has documented interactions with 138 supplements in our database — Rusty-leaved Rhododendron is not one of them. The Regorafenib 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

Rusty-leaved Rhododendron monograph Uses, safety profile, and every drug interaction in one place Regorafenib drug information The full plain-English guide to this medication Regorafenib supplement interactions Every supplement checked against Regorafenib, 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 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Regorafenib and Rusty-leaved Rhododendron?

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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.