Scientific Names of Buckthorn Bark:    

Rhamnus frangula L. [Fam. Rhamnaceae]


Fresh or dried bark of the stem and branches of the frangula species.

Traditional Usage:    

– Anal fissures
– Cellular Regeneration
– Cleansing
– Constipation
– Detoxifying
– Hemorrhoids
– Laxative
– Pre and Post Operative Cleansing


Buckthorn, Rhamnus frangula L. [Fam. Rhamnaceae], also known as Frangula, Arrow Wood, Persian Berries, and Black Alder Bark, is native to Europe, the Mediterranean, northwest Asia, and northern Africa. The bark is primarily used for constipation and for conditions that require a softened stool such as hemorrhoids, anal fissures, and after rectal-anal surgery. The bark of a related North American species, Rhamnus purshiana, is used likewise for the same purposes. The bark is taken from the stem and branches in the spring but must be stored for at least a year or, alternatively, heat treated before using to allow anthrones in the fresh bark to oxidize, otherwise preparations will cause stomach upset. Buckthorn bark is a mild laxative that works by preventing electrolytes and water from being absorbed in the large intestine; the excess liquid softens the stool and promotes bowel contractions. The bark takes about 6 to 8 hours to work after ingestion and should not be used for more than a few days at a time unless otherwise prescribed. Both the German and British Pharmacopoeias recommend Rhamnus frangula bark for constipation and for all disorders in which defecation with a soft stool is desired, e.g. anal fissures, hemorrhoids and after rectal operations. It also recommends a small dose for stomach and bowel catarrh. The active glycosides are hydrolyzed in the gut into their aglycones at least in part by the action of bacterial enzymes; by influencing the water and electrolyte transport in the colon, these aglycones are responsible for the laxative action. Emodin at different concentrations has many therapeutic benefits including: anti-inflammatory at 15mg/kg; antiseptic; antispasmodic; antiulcer, cathartic; vasorelaxant and viricidal. Anthraquinones are also cytotoxic and stimulate cellular regeneration, detoxification and cleansing. Chronic use of anthraquinones-type laxatives, however, often causes pseudomelanosis coli and should be avoided.

Active Ingredients:    

Anthraquinone glycosides, especially glucofrangulins A and B (bis-glycosides with glucose and rhamnose ( = A) and apiose ( = B) and frangulins A and B (monoglycosides containing only apiose): further, frangulaemodin, 8-O-glucoside. In the fresh bark, the glucofrangulins occur mainly in the genuine reduced anthrone and dianthrone glycoside forms (especially frangula-emodin anthrone as rhamnoside/glucoside). On storage (for at least one year) or artificial aging they are converted to the oxidized forms; at the same time the glucofrangulins are partly decomposed to the franguilns or frangula-emodin 8-O-glucoside and to the aglycone frangula-emodin. Also contains physcion and chrysophanol in both free and monoglycosidic forms. In addition there are the steam-volatile 2-acetyl-1,8-dihydronaphthalene and it’s 8-O-glucoside. Tannins as well as small amounts of peptide alkaloids (frangulanin, franganin), are also present. The occurrence of bitter substances and saponins is disputed.

Suggested Amount:    

Tea: Pour boiling water over 2 g of finely chopped Buckthorn bark, steep 10 minutes and then strain. 1 Teaspoon = 2.4 g. Average daily dose is 20-80 mg hydroxyanthracene derivatives. Only aged drug should be used. Anthrones found in the fresh bark will irritate the stomach and may cause vomiting, colic, and bloody diarrhea.

Drug Interactions:    

In large dosages, the anthraquinones-type laxative compounds may increase the action of other laxatives and should not be taken at the same time. With chronic use/abuse, a potassium deficiency may develop that may potentiate the effects of cardiotonic glycosides.


Laxatives are contraindicated in the case of impacted bowel (serious bowel obstruction) or ileus of any origin (danger of intestinal rupture). Stimulant laxatives are also not recommended for the treatment of chronic constipation. Do not use during pregnancy and lactation, or if you have occlusion of the intestines, appendicitis, colitis or Crohn’s disease.

Side Effects:    

Buckthorn Bark should not be taken for long periods of time. Excessive use will result in loss of electrolytes, especially potassium, and may cause muscular weakness, constipation, and pigment deposits in the mucous membranes of the intestines (melanosis coli). A recent study suggested that pseudomelanosis coli is associated with an increased colorectal cancer risk.


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Bradley PR (ed). 1992. Frangula Bark. In British Herbal Compendium. Volume 1. A Handbook of Scientific Information on Widely Used Plant Drugs. British Herbal Medicine Association, Bournemouth, Dorset, pp. 99-101.

Newall CA, Anderson LA, and Phillipson JD. 1996. Cascara. In Herbal Medicines. A Guide for Health Care Professionals. The Pharmaceutical Press, London, pp. 62.

Pojar, J. and A. MacKinnon (Eds.) 1994. Plants of Coastal British Columbia, including Washington, Oregon and Alaska. Publ. by Lone Pine Publishing, 202A-1110 Seymour Street, Vancouver, B.C., Canada, V6B 3N3. Pp. 90-91.

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