Drug & supplement interaction

Cudweed + Dextromethorphan

Dextromethorphan brand names: Hold, Benylin Adult, Benylin Pediatric, Theraflu Thin Strips Long Acting Cough, Neo Citran Thin Strips Cough.

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 Dextromethorphan 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 Dextromethorphan

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 Dextromethorphan 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 Dextromethorphan and Cudweed? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Dextromethorphan

Interactions in our licensed database are recorded against drug classes, not just single drug names. Dextromethorphan is filed under 6 classifications — including serotonergic drugs, serotonergic drugs, cytochrome p450 2d6 (cyp2d6) substrates. Cudweed has documented interactions with 1 drug class — the most serious being antidiabetes drugs (moderate) — and none of Dextromethorphan’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 — Dextromethorphan 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. Dextromethorphan)
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.

From our Q&A

Questions About Cudweed or Dextromethorphan

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

This page covers Cudweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan page lists 171 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 · 125 moderate · 42 minor.

From our pharmacist’s overview on the Dextromethorphan page

“A glass of grapefruit juice can push dextromethorphan (Benylin, Hold, and other cough medicines) to higher levels than intended, one of four major-rated entries among the 171 supplements and herbs on file, and the list as a whole warrants real care. Most interactions trace back to the liver enzymes (CYP3A4 and CYP2D6) that clear dextro…”

Reviewed by 2 · Jul 18, 2026

Open the Dextromethorphan interaction page

How much people look this up

Where Cudweed and Dextromethorphan 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

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

29 days ago today
Medication Dextromethorphan
Top 25%

#538 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 Dextromethorphan 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 Dextromethorphan

What Is Dextromethorphan Used For?

Brand names: Hold, Benylin Adult, Benylin Pediatric, Theraflu Thin Strips Long Acting Cough, Neo Citran Thin Strips Cough

Dextromethorphan temporarily relieves cough due to minor throat and bronchial irritation, such as the kind that comes with the common cold or breathing in irritants. It also helps reduce the urge to cough so you — or your child — can get to sleep.

Some products, including CVS Long Acting Cough and Premier Value Tussin Cough oral liquids, are also indicated to help loosen phlegm (mucus) and thin bronchial secretions to help drain the airways.

See full Dextromethorphan 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 Dextromethorphan, 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 Dextromethorphan Together: Common Questions

Is it safe to take Cudweed with Dextromethorphan?
We do not list a known interaction between Cudweed and Dextromethorphan. 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 Dextromethorphan combination checked?
Interactions in our licensed database are recorded against drug classes. Dextromethorphan is filed under 6 classifications, and Cudweed has documented interactions with 1 drug class — none of Dextromethorphan'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 — Dextromethorphan 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 Dextromethorphan interact with any supplements?
Yes. Dextromethorphan has documented interactions with 171 supplements in our database — Cudweed is not one of them. The Dextromethorphan 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 Dextromethorphan drug information The full plain-English guide to this medication Dextromethorphan supplement interactions Every supplement checked against Dextromethorphan, 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 Dextromethorphan and Cudweed?

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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.