Herb & supplement monograph

Cudweed Drug Interactions, Uses, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated June 2026

What is this page for?

First and foremost: how Cudweed interacts with medications. The heart of this page is the interaction list — every drug Cudweed is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Cudweed is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Cudweed Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Cudweed drug interaction appears low for most people. Every listed interaction is rated moderate rather than major, and all of them trace back to a single theoretical concern that has only been studied in animals.

Interactions deserving the most attention

The one area worth watching is diabetes medications, including insulin, glyburide, glimepiride, and pioglitazone. Early research in rats suggests cudweed might lower blood glucose, so combining it with these drugs could in theory push blood sugar too low. This effect has not been confirmed in people, but because blood sugar is closely monitored and matters day to day, anyone using these medicines should treat the combination with some care.

What the rest of the list means

Although the number of listed medications looks large, nearly all of it reflects that single blood-sugar concern applied across the many drugs used to treat diabetes. The evidence comes from preliminary animal research, not human studies, so a listed interaction here means a possible effect worth knowing about, not a proven harm.

Check your medications against Cudweed

Based on HelloPharmacist’s Cudweed interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Cudweed

86 medications have a known interaction with Cudweed, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Cudweed using our pharmacist-reviewed interaction data.

AI summaries are generated from our Cudweed interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

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What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Cudweed combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Cudweed affects

Every type of medication (drug category) Cudweed is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Cudweed interacts with

Antidiabetes Drugs

Preliminary research in rats shows that cudweed might lower blood glucose levels. Theoretically, taking cudweed with drugs that lower blood glucose levels might increase the risk of hypoglycemia. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), and others.

Likelihood Possible Evidence D

Monograph

Cudweed: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed June 2026 ·

The bottom line

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.

Scientific name: Gnaphalium uliginosum
Family: Asteraceae
Part used: Aerial parts (flowering tops, leaves, and stems)
Common forms: Tea (infusion), tincture, dried herb

People commonly use it for

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

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallLimited data

Limited modern safety data exist, so use with caution and talk to a healthcare provider first.

PregnancyBest avoided

Not enough safety information is available, so avoid use during pregnancy.

BreastfeedingBest avoided

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.

Jump to a section

Overview

Cudweed is a common name shared by several small plants in the daisy (Asteraceae) family, often with soft, woolly or silvery leaves. One plant frequently called cudweed is Gnaphalium uliginosum, also known as marsh cudweed, which grows in damp soils, fields, and roadsides across Europe, Asia, and North America.

In traditional and folk medicine, the dried aerial parts (the leaves, stems, and flowering tops) have been brewed into teas or made into gargles and tinctures. People have used it mainly for throat and mouth irritation, stomach complaints, and minor skin problems.

Cudweed is not a well-studied herb. It is far less common than mainstream supplements, and most of what is written about it comes from older herbal traditions rather than modern clinical research.

Uses & effectiveness

Cudweed has been used traditionally for several purposes, but high-quality scientific evidence is lacking for all of them. Most claims are based on long-standing folk use, not on well-designed human studies.

Sore throat and mouth irritation: Used as a gargle or rinse. Evidence is anecdotal only.
Digestive upset: Taken as a tea for indigestion or stomach discomfort. Not confirmed by clinical research.
Mild high blood pressure: Mentioned in some older herbal sources, but this use is not supported by reliable studies and should not replace proven blood pressure treatment.
Minor wounds and skin irritation: Applied traditionally to the skin. Human evidence is essentially absent.
Coughs and respiratory complaints: Used in folk remedies; effectiveness is unproven.

In short, there is not enough good evidence to say that cudweed works for any health condition. If you choose to try it, treat it as an unproven traditional remedy rather than a substitute for medical treatment.

How it works

The exact way cudweed might affect the body is not well understood. Like many plants in the daisy family, it contains compounds such as flavonoids, tannins, and small amounts of volatile (aromatic) substances.

Tannins can have a mild astringent, or "tightening," effect on tissues, which is one reason astringent herbs have traditionally been used as gargles or for minor skin and gut complaints. Flavonoids found in many plants have antioxidant properties in laboratory tests.

It is important to know that these proposed mechanisms come mostly from general plant chemistry and laboratory or animal observations, not from studies in people taking cudweed. We do not have solid evidence showing how, or whether, it produces meaningful effects in the human body.

Safety & precautions

There is very little modern research on the safety of cudweed, so its full risk profile is unknown. As a general rule, herbs with limited safety data should be used cautiously and only after speaking with a pharmacist or doctor.

People in the daisy (Asteraceae) family of plants — which includes ragweed, marigolds, daisies, and chrysanthemums — can sometimes cause allergic reactions. If you are allergic to any of these, you may be more likely to react to cudweed.

Pregnancy and breastfeeding: Because there is no reliable safety information, cudweed should be avoided during pregnancy and while breastfeeding.

Also use caution if you have a chronic medical condition, take regular medications, or are giving it to children or older adults. Quality and purity of herbal products vary widely, so choose reputable brands and be aware that products may be mislabeled or contaminated.

Side effects

Because cudweed has not been formally studied, its side effects are not well documented. Possible reactions, based on how similar herbs behave, may include:

Allergic reactions, especially in people sensitive to other daisy-family plants (skin rash, itching, or in rare cases more serious reactions)
Mild stomach upset
Skin irritation when applied topically

Stop using cudweed and seek medical care right away if you notice signs of a serious allergic reaction, such as swelling of the face or throat, trouble breathing, or widespread hives.

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. Because product strength and quality differ between brands, it is wise to start low and check with a pharmacist or doctor before use, especially if you take other medicines or have any health conditions.

References & further reading

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.

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

Keep reading

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.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

Pharmacist Counseling Corner

Cudweed: Common Questions

Does Cudweed interact with prescription medications?

Yes. We list 86 medications with a known interaction with Cudweed. Use the checker above to see how Cudweed interacts with a specific drug.

How are Cudweed interactions rated?

Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.

Is it safe to take Cudweed with my medications?

It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.

Where does this Cudweed interaction information come from?

Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.

What is Cudweed used for?

It is used in traditional herbal medicine mainly for sore throats, mouth irritation, digestive upset, and minor skin problems. None of these uses are backed by strong scientific evidence.

Is Cudweed safe to take?

Its safety has not been well studied, so the risks are not fully known. Use it cautiously, choose a reputable product, and check with a pharmacist or doctor first.

Can I use Cudweed while pregnant or breastfeeding?

No. Because there is no reliable safety data, it is best to avoid Cudweed during pregnancy and while breastfeeding.

Does Cudweed actually work?

There is not enough good scientific evidence to say that Cudweed works for any condition. Its uses come from tradition rather than proven research, so it should not replace medical treatment.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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