Drug & supplement interaction

Cudweed + Levocetirizine

Levocetirizine brand name: Xyzal.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Cudweed and Levocetirizine 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 Levocetirizine

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

Why No Interaction Is Listed for Levocetirizine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levocetirizine is filed under 3 classifications — including seizure threshold lowering drugs, oral drugs. Cudweed has documented interactions with 1 drug class — the most serious being antidiabetes drugs (moderate) — and none of Levocetirizine’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 — Levocetirizine isn’t one of them. If you take anything else, check it against the full list below.

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 Levocetirizine’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 Levocetirizine’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. 4 of them are worth acting on rather than waiting out — marked below.

  • Trouble passing urine Worth acting on
  • Fainting Worth acting on
  • Hives Worth acting on
  • Bleeding or bruising Worth acting on
  • Weight gain
  • A stuffy or runny nose
  • Sore throat
  • Dry mouth
  • Cough
  • Drowsiness

Showing the 10 most notable of 16 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 Levocetirizine. 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.

From our Q&A

Questions About Cudweed or Levocetirizine

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 Levocetirizine, 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 Levocetirizine

This page covers Cudweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levocetirizine page lists 25 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (moderate), Biofeedback (moderate), Coffee Charcoal (moderate) and Dendrobium (moderate).

By severity: 1 major · 15 moderate · 9 minor.

From our pharmacist’s overview on the Levocetirizine page

“Activated charcoal is the one entry here I would treat as a hard stop, since it can soak up levocetirizine (Xyzal) in the gut and blunt the dose before it has a chance to work, and it is the only major-rated interaction among the 25 ingredients on this page. Even so, the list as a whole earns genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Levocetirizine interaction page

How much people look this up

Where Cudweed and Levocetirizine 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

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

29 days ago today
Medication Levocetirizine
Top half

#1,343 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 13, 2026. The Cudweed and Levocetirizine 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 Levocetirizine

What Is Levocetirizine Used For?

Brand name: Xyzal

Levocetirizine relieves symptoms of seasonal allergic rhinitis (hay fever) and perennial allergic rhinitis (year-round indoor allergies) — including runny nose, sneezing, and itchy, watery eyes. It also treats the skin symptoms of chronic idiopathic urticaria (hives with no identified cause) in adults and children as young as 6 months of age.

The oral solution is specifically indicated for perennial allergic rhinitis in children 6 months to 2 years of age, and Xyzal oral solution shares this same use. Tablet forms cover seasonal and perennial allergic rhinitis and chronic idiopathic urticaria, though the exact approved age ranges vary by product — always check the labeling for the specific product you are using.

See full Levocetirizine 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
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
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 Levocetirizine Together: Common Questions

Is it safe to take Cudweed with Levocetirizine?
We do not list a known interaction between Cudweed and Levocetirizine. 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 Levocetirizine combination checked?
Interactions in our licensed database are recorded against drug classes. Levocetirizine is filed under 3 classifications, and Cudweed has documented interactions with 1 drug class — none of Levocetirizine'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 — Levocetirizine 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 Levocetirizine interact with any supplements?
Yes. Levocetirizine has documented interactions with 25 supplements in our database — Cudweed is not one of them. The Levocetirizine 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 Levocetirizine 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.