Known interactions

No interactions found.

How to use Tag Alder

Scientific Name: Black Alder

Other Names: Alnus glutinosa, Betula Alnus, Common Alder, English Alder, European Alder, Owler, Tag Alder

Who is this for?

Historically, black alder has been used to treat conditions as diverse as cancer and intestinal worms. However, no scientific evidence supports taking black alder by mouth for any medical condition. Today, black alder is used only rarely – usually as a gargle to relieve sore throats or as a soak to soothe tired, aching feet.

When should I be careful taking it?

Black alder bark contains up to 20% of chemicals known as tannins. Although no side effects have been reported from using black alder as a gargle or foot soak, oral preparations of other herbal products that are high in tannin content have been associated with kidney or liver damage. Tannins possibly may be absorbed through the skin as well as through the mucous membranes of the mouth and throat. Therefore, individuals who have kidney or liver conditions should not use black alder in any form.

Because so little is known about black alder and its possible effects on a developing fetus, an infant, or a small child; its use is not recommended for pregnant or breast-feeding women or children under the age of 18.

What side effects should I watch for?

Fresh black alder bark should never be taken by mouth because it contains chemicals that may cause intense vomiting.

No side effects have been reported from the topical use of black alder.

What interactions should I watch for?

No interactions between black alder and prescription drugs, non-prescription drugs, other herbal products, or foods have been reported. However, because few reliable studies of black alder have been conducted in humans, its possible interactions are not understood completely.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals.

Should I take it?

Black alder is a smallish tree that is native to cool parts of Africa, Asia, and Europe. Although it has been introduced in eastern Canada and the northeastern United States, it does not grow well in the North American climate. Black alders often form clumps in wet areas of pastures or near swampy regions. The lightweight wood from young trees is used for carving and for making cigar boxes. Wood from older black alder trees is especially resistant to water and it has been used extensively to make water pumps, animal watering troughs, and boat docks. Several parts of the tree are used for dyes that range in color from deep red through yellow-gray. The bark was formerly used in tanning leather. For medicine, the part used is the aged bark, which has been dried and shredded or powdered.

Dosage and Administration

For medicinal use, a topical preparation may be made by boiling one teaspoon of dried, powdered black alder bark in 8 ounces of water for about 2 minutes. After the liquid is cooled and the solid particles are strained out, the liquid may be used as a mouthwash or gargle. Larger quantities may be made and used warm as a foot soak. This liquid should not be taken by mouth.


Black alder bark may be made into a liquid for a mouthwash or a foot bath.


Due to the possibility that tannins may be absorbed through mucous membranes or skin, individuals with kidney or liver conditions should not use black alder products. Pregnant or breast-feeding women and children under the age of 18 should also avoid its use.

Side Effects

Intense vomiting may result from ingesting fresh black alder bark.


No interactions are known to occur when black alder is used as a foot soak, gargle, or mouthwash.


Chung KT, Wong TY, Wei CI, Huang YW, Lin Y. Tannins and human health: a review. Critical Reviews in Food Sciences and Nutrition. 1998 Aug;38(6):421-464.

Duke JA. Handbook of Energy Crops (unpublished). 1983. Available at: Accessed May 27, 2003.

Grieve M. Alder, common. In: A Modern Herbal. New York: Dover Publishers, 1971. Available at: Posted 1995. Accessed May 27, 2003.

Jellin JM, Gregory P, Batz F, Hitchens K, et al, eds. Pharmacist's Letter/Prescriber's Letter. Natural Medicines Comprehensive Database, 3rd Edition. Stockton CA: Therapeutic Research Facility, 2000.

Ohio Department of Natural Resources and the Ohio State University Department of Horticulture and Crop Science. Ohio's Trees. 2002. Available at: Accessed: July 1, 2003.

(Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.)

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