Buckthorn Overview

The medicinal herb known as common buckthorn is a shrub originally native to northern Europe. It was later brought to the United States, where, in some areas, it has become an invasive pest. Not to be confused with the entirely different plant sea buckthorn , common buckthorn is an intensely active laxative. The berries and bark are the parts used medicinally.

Buckthorn is related to cascara sagrada ( Rhamnus purshiana), a milder laxative widely available in the US as an over-the-counter drug. Like cascara, as well as the OTC laxative senna , buckthorn contains substances in the anthranoid family including anthraquinones, anthrones, and dianthrones. Anthroids work by slightly damaging the cells lining the colon. ¹ This in turn causes colon contraction, leading to bowel movements.

The fact that the laxative actions of anthroids involves cell damage has raised concerns that they might increase colon cancer risk. This does not appear to be the case; however, for a discussion of this controversial topic, see the Senna article.

A typical dose of buckthorn provides 20-30 mg of anthrones, often measured in the form of glucofrangulin A. Like cascara and senna, it is usually taken at bedtime with the intention of producing a bowel movement in the morning.

Buckthorn must be allowed to dry for several months before it is taken internally. This drying process reduces levels of tannins and other irritants that would otherwise almost certainly cause severe nausea.

1. van Gorkom BA, de Vries EG, Karrenbeld A, Kleibeuker JH. Review article: anthranoid laxatives and their potential carcinogenic effects. Aliment Pharmacol Ther. 13(4):443-52.