Drug & supplement interaction

Cudweed + Valrubicin

Valrubicin brand name: Valstar.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Cudweed and Valrubicin 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

Cudweed and Valrubicin

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 Valrubicin and Cudweed 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.

Cudweed safety at a glance

Cudweed overall Not established Limited modern safety data exist, so use with caution and talk to a healthcare provider first.
Pregnancy Avoid Not enough safety information is available, so avoid use during pregnancy.
Breastfeeding Avoid There is no reliable safety data, so avoid use while breastfeeding.

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

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

Why No Interaction Is Listed for Valrubicin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Valrubicin is filed under 3 classifications — topoisomerase ii inhibitors, antitumor antibiotics, oral drugs. Cudweed has documented interactions with 1 drug class — the most serious being antidiabetes drugs (moderate) — and none of Valrubicin’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

Cudweed Does Interact With Other Medications

Cudweed has 86 moderate known drug interactions in our database — Valrubicin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Valrubicin)
Taking anything else?

Check Another of Your Medications Against Cudweed

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

What to actually watch for

What Valrubicin’s Own FDA Label Lists

This is not an interaction — none of it involves Cudweed. These are the most notable effects listed in the ADVERSE REACTIONS section of Valrubicin’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 6 of them are worth acting on rather than waiting out — marked below.

  • Pain or burning when passing urine Worth acting on
  • Trouble passing urine Worth acting on
  • High blood sugar Worth acting on
  • Chest pain Worth acting on
  • Anemia Worth acting on
  • A higher chance of infection Worth acting on
  • Loss of bladder control
  • Passing urine more often
  • Bloating or gas
  • Back pain

Showing the 10 most notable of 22 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Valrubicin. Read the label on DailyMed › Cudweed’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Cudweed side to compare — that is a limit of the record, not a statement that Cudweed has no side effects.

Everything else you take

See Every Supplement That Interacts With Valrubicin

This page covers Cudweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Valrubicin page lists 24 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Acerola (moderate), Alpha-lipoic Acid (moderate), Coffee Charcoal (moderate) and European Mandrake (moderate).

By severity: 1 major · 14 moderate · 9 minor.

From our pharmacist’s overview on the Valrubicin page

“Activated charcoal is the supplement I would flag hardest for anyone receiving valrubicin (Valstar), a chemotherapy instilled directly into the bladder for cancer. It carries the only major rating among the 24 ingredients on this page, since charcoal can bind and clear many drugs from the body even when they are not swallowed.”

Reviewed by 2 · Jul 18, 2026

Open the Valrubicin interaction page

How much people look this up

Where Cudweed and Valrubicin 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 Cudweed
Top half

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

29 days ago today
Medication Valrubicin
Steady interest

#2,736 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 Cudweed reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Cudweed and Valrubicin records this page draws on were last updated June 20, 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 Cudweed

What is Cudweed?

  • Mouth and throat irritation
  • Digestive upset
  • Mild high blood pressure (traditional)
  • Minor wounds and skin irritation
  • Coughs and respiratory complaints

Cudweed is a small, woolly-leaved plant used in traditional herbal medicine, mainly as a tea or gargle for sore throats, digestive upset, and minor skin problems. There is very little modern scientific evidence to confirm that it works for any condition, and safety data are limited, so it is best used cautiously and avoided in pregnancy and breastfeeding.

Gnaphalium uliginosum · Asteraceae · Aerial parts (flowering tops, leaves, and stems) · Tea (infusion), tincture, dried herb

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

Cudweed: dosing

There is no established or standardized dose for cudweed. It has not been studied enough to know a safe and effective amount, and traditional preparations vary.If you choose to use a commercial product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Cudweed monograph & all interactions
Medication

About Valrubicin Intravesical

What Is Valrubicin Intravesical Used For?

Brand name: Valstar

Valrubicin Intravesical Solution is used to treat BCG-refractory carcinoma in situ (CIS) of the urinary bladder — meaning bladder cancer that has not responded to BCG immunotherapy. It is given directly into the bladder (intravesically) rather than taken by mouth or injected into the bloodstream.

This treatment is specifically for patients whose cancer has not responded to BCG and for whom having the bladder surgically removed (cystectomy) right away would carry unacceptable health risks.

Most-Reported Side Effects for Valrubicin

From FAERS, the FDA’s public side-effect reporting system (177 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Underdose 26 reports
Bladder instillation procedure 24 reports
Urge incontinence 20 reports
Bladder spasm 13 reports
Urinary incontinence 11 reports
See full Valrubicin Intravesical drug information
Keep checking

Other Drugs & Cudweed

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Cudweed page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Cudweed list.

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

Cudweed References

The 1 references that drive our Cudweed 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. Shikov AN, Pozharitskaya ON, Makarov VG, et al. Medicinal plants of the Russian Pharmacopoeia; their history and applications. J Ethnopharmacol 2014;154(3):481-536. 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 Cudweed and Valrubicin Together: Common Questions

Is it safe to take Cudweed with Valrubicin?
We do not list a known interaction between Cudweed and Valrubicin. 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.
How was the Cudweed and Valrubicin combination checked?
Interactions in our licensed database are recorded against drug classes. Valrubicin is filed under 3 classifications, and Cudweed has documented interactions with 1 drug class — none of Valrubicin'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 Cudweed interact with any other medications?
Yes. Cudweed has 86 documented drug interactions in our database — Valrubicin 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 Valrubicin interact with any supplements?
Yes. Valrubicin has documented interactions with 24 supplements in our database — Cudweed is not one of them. The Valrubicin 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

Cudweed monograph Uses, safety profile, and every drug interaction in one place Valrubicin Intravesical drug information The full plain-English guide to this medication Valrubicin supplement interactions Every supplement checked against Valrubicin, 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Valrubicin and Cudweed?

Our pharmacists answer your medication & supplement questions — free.

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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.