During the Middle Ages, burdock was valued for treating a host of ailments. English herbalists even preferred burdock root over sarsaparilla in remedies for boils, scurvy, and rheumatism. Burdock played an important role in Native American medical botany, and American herbalists have used the roots and seeds of this plant for two centuries.

Burdock root is traditionally classified as an alterative (blood purifier) and analgesic. It also acts as a diaphoretic (promoting profuse perspiration). While the leaf and root have similar pharmacological properties, most herbal remedies call for burdock root.

Burdock root is listed in the Eclectic Materia Medica, the U.S. Pharmacopoeia, and the official pharmacopoeia of several other countries. The root is used in remedies for arthritis, gout, and related inflammatory conditions. Diuretics are made from powdered burdock seeds, which yield a yellow bland fixed product called oil of lappa.

Burdock is a biennial common weed native to Europe and northern Asia, but now widespread throughout the United States. A member of the thistle family, it is a stout, dull pale-green plant with many spreading branches. It reaches a height of three to four feet, and its purple flowers bloom between June and October. Burdock has alternate, wavy, heart-shaped leaves that are green on the top and whitish on the bottom. The deep roots are brownish-green, or nearly black on the outside.

This plant is rarely cultivated because it easily flourishes in the wild, and it grows optimally in light, well-drained soils. The leaves are collected during the first year of growth. The roots are harvested in the fall of the first year (or in the following spring before the flowers bloom), and then air-dried.

• Leaves
• Roots (rhizome)
• Whole herb

Sesquiterpene lactones; polyynes (mainly trideca-1,11-dien-3,5,7,9-tetrain); caffeic acid derivatives (including chlorogenic acid, isochlorogenic acid); carbohydrates (45% to 50% inulin [fructosan], mucilages); volatile oil of complex composition (phenylacetaldehyde, benzaldehyde, 2-alkyl-3-methoxy-pyrazines); phytosterols, tannins.

Commercial preparations are made from the fresh or dried underground parts (usually from Arctium lappa but sometimes from the related species Arctium minus and/or Arctium tomentosum).

Burdock was historically used for pulmonary catarrh, arthritis and rheumatic conditions, scurvy, and venereal eruptions. It was externally applied for skin problems and applied to the forehead and soles to lessen symptoms of fever.

Burdock's traditional herbal actions are alterative, diuretic, laxative, digestive bitter, cholagogue, lymphatic cleanser, and diaphoretic. Herbalists use burdock root and leaves as a poultice for infected wounds and pimples, and it has traditionally been used as a part of blends for cancer therapy such as the Essiac formula. Herbalists warn that large doses can precipitate skin eruptions, headache, and aching joints due to excessive elimination.

Today, burdock is clinically used for a variety of skin problems, including psoriasis, eczema, contact dermatitis, skin eruptions (particularly on the head and neck), osteo and rheumatoid arthritis, and gout.

Investigations conducted in the mid-1940s indicated that burdock leaf is active against gram-negative bacteria. While burdock root has only shown antibacterial activity against gram-negative strains, the leaf and flower exhibited anti-bacterial effects against both gram-negative and gram-positive strains. The roots and leaves have antifurunculous effects and are used to treat furuncles, or boils.

Burdock reportedly has hypoglycemic properties, but the findings are contradictory. In one study, burdock extract produced a prolonged reduction in blood-sugar concentration accompanied by a rise in carbohydrate tolerance. However, in another investigation, burdock actually aggravated the diabetic condition in streptozotocin diabetic mice. In this study, burdock adversely affected parameters of glucose homeostasis, including basal glucose, basal insulin, insulin-induced hypoglycemia, and pancreatic insulin concentration.

In an in vivo experiment, both fresh and boiled burdock plant juice significantly lowered 7,12-dimethylbenz[a]anthracene (DMBA)-induced chromosome aberrations in rat bone marrow cells. DMBA usually produces chromosome aberrations of gaps and breaks, and only rarely causes more serious chromosome damage in the form of exchanges. Burdock suppressed the incidence of DMBA-induced aberrant metaphase cells (excluding cells with gaps). This suggests that burdock may block the onset of chemically induced carcinogenesis. In another investigation, burdock decreased the mutagenicity caused by Salmonella mutagens and toxins (both S9-metabolic-activating and non–S9-metabolic activating mutagens).

Recommended dosage:

• Dried root: 2 to 6 g in decoction tid
• Tincture (1:5): 8 to 12 ml tid
• Fluid extract (1:1): 2 to 6 ml tid
• Tea: 2 to 6 g in 500 ml water

Adverse side effects have been reported for an isolated case of a patient taking burdock. However, experts eventually concluded that the adverse reaction was not due to burdock, but instead to contamination from solanaceous alkaloids (probably in belladonna leaf).

According to the German Commission E, there are no known risks associated with the use of burdock. However, skin contact with burdock root has the potential for sensitization. There is a very slight risk of contact dermatitis when using burdock root plasters. Burdock should not be taken by pregnant and lactating women since this plant has in vivo uterine stimulant effects. As a general precaution, excessive amounts of burdock root should not be consumed because the toxicology of this plant is not well understood.

Although burdock reportedly possesses hypoglycemic potential, no clinically significant interactions with conventional medications (including antidiabetic medications) are known to have been reported in the literature to date, including the German Commission E monograph (Blumenthal 1998).

The U.S. FDA classifies burdock as a dietary supplement. The root and leaf are on the General Sale List, Schedule 1, Table A [R1a] in the UK. Burdock root is sold as a nonpresription drug in France and Germany.

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