Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what Black Alder 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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Black Alder 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 Black Alder drug interaction appears low for most people, though anyone receiving chemotherapy should take extra care. Only a couple of interactions are known, both rated moderate, and neither has been confirmed in humans.

Interactions deserving the most attention

The concerns that stand out both involve chemotherapy. Laboratory research suggests black alder bark extracts may work against the cancer-fighting effects of cisplatin and doxorubicin. Because these medicines are used to treat cancer, anything that could weaken them matters, even when the evidence is early. We think people receiving either drug should treat this combination cautiously and raise it with their oncology team.

What the rest of the list means

It helps to know that both findings come from lab studies only, so it is not yet clear whether the same effect happens in people. Still, when a medication's job is as critical as fighting cancer, even a theoretical risk deserves respect. For those not taking these chemotherapy drugs, Black Alder has no other documented drug interactions at this time.

Check your medications against Black Alder

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

Interaction report

Drugs that interact with Black Alder

2 medications have a known interaction with Black Alder, 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 Black Alder using our pharmacist-reviewed interaction data.

AI summaries are generated from our Black Alder 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 Black Alder 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 Black Alder affects

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

All 2 drug categories Black Alder interacts with

Cisplatin (platinol-aq)Doxorubicin (adriamycin, Others)

Cisplatin (Platinol-Aq)

Laboratory research shows that black alder bark extracts can antagonize the chemotherapeutic effects of cisplatin. This interaction has not been evaluated in humans. Until more is known, use this combination with caution.

Likelihood Possible Evidence D

Doxorubicin (Adriamycin, Others)

Laboratory research shows that black alder bark extracts can antagonize the chemotherapeutic effects of doxorubicin. This interaction has not been evaluated in humans. Until more is known, use this combination with caution.

Likelihood Possible Evidence D

Monograph

Black Alder: Uses, Safety & Side Effects

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

The bottom line

Black Alder is a European tree whose bark and leaves have a long history in folk medicine, mainly as an astringent gargle or wound wash. There is very little modern human research to confirm any of these uses, and it can cause stomach upset, so it should be used cautiously and avoided during pregnancy and breastfeeding.

Scientific name: Alnus glutinosa
Family: Betulaceae
Part used: Bark, leaves, and sometimes the catkins
Common forms: Dried bark or leaf for tea, decoctions, tinctures, and gargles or mouth rinses

People commonly use it for

Sore throat and mouth inflammation
Skin wounds and irritation (topical)
Fever and general aches (traditional)
Digestive complaints
Astringent for minor bleeding

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

Safety at a glance

OverallUse caution

Limited safety data exist and it may cause nausea or stomach upset, so use cautiously and briefly.

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

Black Alder (Alnus glutinosa) is a deciduous tree native to Europe, parts of Asia, and North Africa. It often grows in wet areas like riverbanks, marshes, and damp woodlands. It is also called common alder, European alder, or English alder.

In traditional herbal practice, the bark and leaves have been used to make teas, gargles, and washes. People most often used it as an astringent, meaning it was thought to tighten tissues, help with sore throats, and clean minor wounds.

It is important not to confuse this tree with other plants that share similar common names, such as "black alder" used for American winterberry (Ilex verticillata), which is a different plant entirely.

Uses & effectiveness

Black Alder has been used in folk medicine for sore throats, mouth and gum irritation, minor skin wounds, fevers, and digestive upset. Most of these uses come from tradition rather than modern science.

Laboratory studies have looked at compounds in alder for possible anti-inflammatory and antimicrobial effects. These early findings are interesting, but they are mostly from test-tube or animal research. There is not enough good-quality human research to know whether Black Alder actually treats any condition in people.

Because the evidence is so limited, Black Alder should not be relied on in place of proven treatments. If you have an infection, persistent sore throat, or a wound that is not healing, see a healthcare provider.

How it works

Black Alder bark and leaves contain tannins, which are astringent compounds that can tighten tissue and may give a drying or soothing feeling on mucous membranes. This is the likely reason it was traditionally used as a gargle or wound wash.

The plant also contains flavonoids and other plant compounds (such as diarylheptanoids) that have shown anti-inflammatory and antimicrobial activity in laboratory studies.

It is important to understand that these proposed mechanisms are based mainly on lab and animal research. They do not prove that the herb works the same way, or has any benefit, in the human body.

Safety & precautions

There is very little formal safety information on Black Alder. Because of this, it should be used cautiously and only for short periods, if at all.

Accurate identification matters. Several plants share the "alder" or "black alder" name, and some are more toxic than others. Using the wrong plant could be harmful.

People with stomach sensitivity, ulcers, or kidney problems should be especially careful, since tannin-rich herbs can irritate the gut. Pregnant and breastfeeding people should avoid it because there is no reliable safety data. Do not give it to infants or young children.

Always talk with a pharmacist or doctor before using Black Alder, especially if you take other medicines or have a health condition.

Side effects

The most likely side effects come from its tannin content and include nausea, stomach upset, or vomiting, especially if a strong preparation is swallowed.

Applied to the skin or used as a mouth rinse, it may cause irritation in some people. Rarely, any plant product can cause an allergic reaction. Stop using it and seek medical help if you notice rash, swelling, or trouble breathing.

Because solid safety studies are lacking, other side effects are simply not well known.

Dosing

There is no established, standardized dose for Black Alder. Traditional use involved making a tea or decoction from the dried bark or leaves, or using a diluted preparation as a gargle or skin wash.

If you choose to use a product, follow the directions on the label and do not exceed the recommended amount. Because strength varies widely between products, it is best to check with a pharmacist or doctor first.

When using any new herb, starting low and using it only for a short time is the safest approach.

Pregnancy & Breastfeeding

Black Alder & Pregnancy

Insufficient reliable information

Insufficient reliable information available; avoid using.

Black Alder & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 1 references that drive our Black Alder 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.

Dinic J, Novakovic M, Podolski-Renic A, et al. Antioxidative activity of diarylheptanoids from the bark of black alder (Alnus glutinosa) and their interaction with anticancer drugs. Planta Med 2014;80(13):1088-96. doi: 10.1055/s-0034-1382993. Epub 2014 Au 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.

Brand directory

Brands that make products with Black Alder

2 brands in our database make a supplement containing Black Alder.

Genestra Brands 998 products UNDA Gemmo 67 products

Product directory

Supplement products with Black Alder

21 products in our database contain Black Alder. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Black Alder: Common Questions

Does Black Alder interact with prescription medications?

Yes. We list 2 medications with a known interaction with Black Alder. Use the checker above to see how Black Alder interacts with a specific drug.

How are Black Alder 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 Black Alder 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 Black Alder 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 Black Alder used for?

Traditionally, it has been used as an astringent gargle for sore throats, as a wash for minor wounds, and for fevers or digestive complaints. Modern evidence supporting these uses is very limited.

Is Black Alder safe to take?

There is little safety data, and it can cause nausea or stomach upset, so it should be used cautiously and only briefly. Talk to a pharmacist or doctor before using it.

Can I use Black Alder during pregnancy or breastfeeding?

No. Because there is not enough information about its safety, it is best to avoid Black Alder during pregnancy and while breastfeeding.

Is Black Alder the same as the 'Black Alder' in some cold remedies?

Not always. Several different plants are called 'Black Alder,' including American winterberry (Ilex verticillata), so correct identification is important before using any product.

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

Keep exploring

Products that contain Black Alder

A rotating sample of real supplements in our database that list Black Alder — open any to see its full ingredients and every drug interaction we check.

See all 21 products with Black Alder →

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Black Alder Drug Interactions, Uses, Safety & More

Your Choice:

Black Alder Drug Interactions: The Bottom Line

Drugs that interact with Black Alder

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

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Likelihood — How Well It’s Documented

Where This Data Comes From

The kinds of drugs Black Alder affects

Black Alder: Uses, Safety & Side Effects

Overview

Uses & effectiveness

How it works

Safety & precautions

Side effects

Dosing

Black Alder & Pregnancy

Black Alder & Breastfeeding

References & further reading

Brands that make products with Black Alder

Supplement products with Black Alder

Black Alder: Common Questions

Related supplements & herbs

Products that contain Black Alder

Have a question about Black Alder?