Alder Buckthorn
Scientific Name: Rhamnus frangula
Other Names: Alder Dogwood, Arrow Wood, Black Dogwood, Dog Wood, European Buckthorn, Frangula Bark, Glossy Buckthorn
Should I take it?
Commonly known as alder buckthorn or glossy alder, Rhamnus frangula grows as a small tree throughout Britain, much of Europe and the U.S. Although it is called dog wood in many parts of the world, Rhamnus frangula is not the same as the flowering dogwood trees common in the American Midwest. Unlike related trees, it does not have thorns. Its shiny leaves, water tolerance, and fast growth make it popular for fence rows in damp areas of Britain. Rhamnus frangula bears small greenish flowers in the spring and dark red, purple, or black berries in the fall. It was much valued by 19th century weavers because its unripe berries produce a greenish dye; its ripe berries a blue-gray color; and its leaves and twigs a bright yellow, which turns black if iron is added.
During the summer, bark is collected from Rhamnus frangula branches that have been cut for use in making charcoal. The bark must be dried and aged for at least one year (if dried naturally) or processed under specific conditions (if cured in a commercial facility). Improperly cured or fresh bark contains chemicals, including emodin, that cause severe vomiting.
Dosage and Administration
Caution: Fresh Rhamnus frangula should never be taken orally because it contains emodin and other chemicals that cause severe vomiting. Individuals who decide to use Rhamnus frangula are advised to use a commercial product rather than collecting it from trees.
Rhamnus frangula is available as capsules, liquid extracts, or tablets that all have been made from the tree bark after it has been aged, dried, and powdered. Commercial preparations of Rhamnus frangula usually are standardized according to their content of an anthraquinone known as glucofrangulin A. Standardization by the manufacturer should assure the same amount of active ingredient in every batch of the commercial preparation. Although dosing recommendations for Rhamnus frangula are not consistent, the European agency responsible for herbal medicines sets the maximum amount of glucofrangulin A at 30 mg per day.
In some countries, Rhamnus frangula may be purchased in bulk as bark chunks or powder. Rhamnus frangula tea is made by soaking 2000 mg (2 grams) of dried, aged bark in about 5 ounces of boiling water for 5 minutes to 10 minutes, straining out the solid particles, and drinking the liquid. Because Rhamnus frangula has a strongly bitter taste, the tea is often sweetened or flavored to make it taste better. Common recommendations for the use of Rhamnus frangula bark powder range from 500 mg to 2,500 mg (0.5 gram to 2.5 grams) of the aged, powdered bark per day. Because it may take up to 8 hours to work, Rhamnus frangula is often taken at bedtime. Individuals who decide to use it, should follow exactly the recommendations on the package of the product that is purchased.
Only the smallest amount of Rhamnus frangula that produces a stool should be taken. Rhamnus frangula should be used only long enough to correct constipation--no longer than 7 days to 10 days because prolonged use has been associated with the loss of potassium from the body. Potassium levels that are too low can cause muscle weakness and heart rhythm changes. If diarrhea occurs, its use should be stopped.
Summary
Aged bark of Rhamnus frangula is used as a laxative.
Risks
Due to its irritating effect on the gastrointestinal (GI) tract, Rhamnus frangula should not be used by individuals with inflammatory bowel diseases. Children under the age of 12 and women who are pregnant or breast feeding should also avoid its use, as should those who have or have had intestinal blockages. Abdominal or stomach pain that does not have obvious sources may be an indication of a condition that using Rhamnus frangula could worsen. No laxative should be used if such pain is present. Rhamnus frangula should not be used for longer than 10 days at a time.
Side Effects
Fresh Rhamnus frangula bark may cause intense vomiting. Side effects associated with dried Rhamnus frangula include stomach cramps and discolored stools or urine.
Interactions
If Rhamnus frangula is taken at the same time as corticosteroids, water pills, or large amounts of licorice; potassium levels in the body may get too low. If it is taken at the same time as digoxin, Rhamnus frangula could increase the risk of digoxin's side effects. Rhamnus frangula can increase the laxative effects and the risk of low potassium levels if it is taken with laxative medications or herbals.
Last Revised April 17, 2008
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Should I take it? 
