Herb & supplement monograph

Sweet Woodruff Drug Interactions, Uses, Effectiveness, Safety & More

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

What is this page for?

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

But these pages have grown well beyond that into a full monograph — what Sweet Woodruff 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

Check Sweet Woodruff against your medication

Add one medication

✓ Supplement

Sweet Woodruff

1 Your medication

Start typing any prescription or over-the-counter drug name.

Reviewed by licensed pharmacists Sourced from Natural Medicines

On this page

Sweet Woodruff 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 Sweet Woodruff drug interaction appears low for most people. None of the listed interactions are rated major, and every one traces back to a single theoretical concern that current evidence suggests is unlikely to matter in real life.

Interactions deserving the most attention

The only interaction worth watching involves anticoagulant and antiplatelet drugs, the medications used to prevent blood clots. Sweet woodruff naturally contains coumarin, a compound related to some blood thinners, so in theory it could add to their effects and raise bleeding risk. In practice, the amount of coumarin in sweet woodruff is so small that a meaningful effect is doubtful. Because bleeding risk is closely watched with these medicines, we still suggest a cautious approach for anyone taking a blood thinner.

What the rest of the list means

Although the list of interacting medications looks long, it does not mean each combination is harmful. Nearly all of these entries come from that one theoretical bleeding concern applied across many blood-thinning drugs, and the predicted effect has not been shown to cause meaningful problems in people.

Check your medications against Sweet Woodruff

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

Interaction report

Drugs that interact with Sweet Woodruff

122 medications have a known interaction with Sweet Woodruff, 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 Sweet Woodruff using our pharmacist-reviewed interaction data.

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

2,830 drugs

Read The List Like a Pharmacist

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 Sweet Woodruff 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 Sweet Woodruff affects

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

All 1 drug category Sweet Woodruff interacts with

Anticoagulant/antiplatelet Drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, concomitant use might increase the effects of some anticoagulant and antiplatelet drugs and increase the risk of bleeding.
Sweet woodruff contains coumarin and coumarin derivatives. However, the levels of coumarin found in sweet woodruff are so low that clinically relevant effects are doubtful. Until more is known, use with caution.

Likelihood Unlikely Evidence D

Monograph

Sweet Woodruff: Uses, Safety & Side Effects

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

The bottom line

Sweet woodruff is a fragrant European herb traditionally used for digestion, calming, and various other complaints, but solid human evidence for any of these uses is lacking. It contains coumarin, which can be harmful in large amounts, so it should be used only sparingly and avoided during pregnancy and breastfeeding. Talk to your pharmacist or doctor before using it.

Scientific name: Galium odoratum
Family: Rubiaceae
Part used: Above-ground parts (leaves, flowering tops, and stems)
Common forms: Dried herb, tea, tinctures, and traditional flavoring (for example in some wines and beverages)

People commonly use it for

Digestive upset
Anxiety, restlessness, and sleep
Liver and gallbladder complaints
Urinary tract problems
Respiratory complaints
As a flavoring agent

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

Safety at a glance

OverallUse caution

Generally used in small amounts as a flavoring, but its coumarin content can be harmful in larger or long-term doses.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Sweet woodruff (Galium odoratum) is a low-growing perennial herb in the bedstraw family (Rubiaceae). It is native to Europe and parts of Asia and grows in shady woodlands. It is also widely grown as a garden ground cover.

When the plant is dried, it develops a sweet, hay-like or vanilla scent because of a natural compound called coumarin. Because of this pleasant smell, sweet woodruff has traditionally been used to flavor certain drinks (such as the German "Maiwein" or May wine) and to scent linens.

In folk medicine, the above-ground parts have been used to make teas and other preparations for a range of complaints, including digestive, urinary, and nervous problems. Today it is much more popular as a flavoring and ornamental plant than as a medicine.

How it works

The most notable compound in sweet woodruff is coumarin, which is responsible for its sweet smell. The plant also contains other substances such as tannins (which give an astringent effect), flavonoids, and small amounts of iridoid compounds.

In traditional use, the astringent tannins were thought to help with digestive and skin complaints, while the plant was also believed to have mild calming and diuretic effects. These ideas are based largely on tradition and laboratory observations rather than well-designed human studies.

It is important to know that coumarin is not the same as the blood thinner "warfarin," although the names sound similar. Still, large amounts of coumarin can be hard on the liver, which is one reason this herb should be used carefully.

Effectiveness

Does Sweet Woodruff work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 10 uses evaluated

10 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

For Sweet Woodruff, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 10 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Angina