What Is Burdock?

Native to Europe and Asia and now naturalized in North America, burdock (Arctium lappais) is a plant that—along with daisies and sunflowers—belongs to the Asteraceae family. It's well-named, as the fruit of the plant, a round ball of seed material covered in hooks or teeth, resembles a bur that sticks to anything. In fact, its gripping action was the inspiration for Velcro.

Burdock may be considered a weed in some states (due to its ability to spread), but the herb has been employed for centuries as a remedy for a wide range of ailments. In traditional medicine, burdock fruits, seeds, roots, and leaves have been used as decoctions or teas for colds, gout, rheumatism, stomach ailments, and cancer, as well as used to promote urination, increase sweating, and facilitate bowel movements. It's also been promoted as an aphrodisiac.

Though all aspects of the plant are used, it's the carrot-shaped white root—which can grow to two feet and contains the greatest amount of nutrients—that seems to possess most of the purported healing power of burdock. The root contains numerous phytochemicals, including lignans, triterpenoids, and polyacetylenes, some of which have been shown to promote blood circulation (hence its reputation as a detoxifying agent) and are linked to antidiabetic properties. Other components include flavonoids that have exhibited cytotoxic, anti-inflammatory, and antioxidant effects, which may explain its use both internally and externally for many conditions of the skin, such as acne, burns, boils, and eczema. Research shows that burdock root, which is commonly eaten in Japan, some parts of Europe, as well as increasingly in the U.S., is also a source of inulin, a type of prebiotic fiber that feeds the good bacteria in the large intestine to improve digestion.

What Is Burdock Used For?

Few scientific studies have explored burdock's health effects, and though some of the research is promising, it should be considered preliminary. Here's a rundown on what is known.

Diabetes

In a 2017 study, diabetic mice pretreated with 200 milligrams and 300 milligrams of burdock root extract for a month increased the levels of insulin and also helped control body weight. Researchers also reported favorable changes in blood lipid profiles, including decreased levels of triglycerides and LDL "bad" cholesterol and increased levels of HDL "good" cholesterol. The study builds on a 2014 study of diabetes in mice which suggested that, because of its antioxidant properties, burdock may improve symptoms of diabetes. 

High Cholesterol

In a study to identify potential genes that may be involved in lipid metabolism, burdock root extract reduced body weight and cholesterol levels in rats, possibly by modulating the expression of genes.

Liver Support

While burdock has been lauded for its blood-purifying properties, there is limited evidence of its liver-supporting capabilities. A 2002 study found the herb helped reverse liver damage caused by excessive alcohol consumption in rats, though a direct correlation to results in humans cannot necessarily be made. In another animal study, burdock helped to protect against liver damage caused by nonsteroidal anti-inflammatory drugs (NSAIDs) like Tylenol (acetaminophen) and carbon tetrachloride, a chemical solvent.

Cancer

Burdock is one of the key ingredients of Essiac and Flor-Essence, herbal formulas marketed as wonder remedies for people coping with cancer. While advocates claim that Essiac and Flor-Essence can shrink tumors, prolong survival, provide pain relief, and boost immunity, there's no evidence supporting such claims, according to a report from Memorial Sloan Kettering Cancer Center. What's more, one 2006 study found Essiac and Flor-Essence may actually stimulate the growth of human breast cancer cells.

In addition to burdock, Essiac contains slippery elm inner bark, sheep sorrel, and Indian rhubarb root. Flor-Essence includes the same ingredients, as well as watercress, blessed thistle, red clover, and kelp.

Skin Health

One study from 2017 that investigated the effects of an extract from burdock leaves on skin aging found that the antioxidants it contained were able to inhibit enzymes that led to wrinkling and excess pigmentation. However, a study from 2014 that examined the effects of a burdock leaf dressing on burns found that it was toxic to skin cells and didn't demonstrate any antimicrobial activity. One small study from 2014 that used a homeopathic preparation of burdock found significant improvements in number and types of pimples and quality of life scores.

Sexual Desire

An experiment in rats found that an extract of burdock root enhanced sexual behavior, though not to the same degree as Viagara (sildenafil), a drug used to treat erectile dysfunction. It also increased serum testosterone levels, compared with the control. According to the researchers, the results support the traditional use of burdock root for treating impotence and sterility.

Pain Relief

A 2014 study found drinking burdock root tea lowers certain inflammatory markers in patients with knee osteoarthritis.

Selection, Preparation, & Storage

Fresh burdock root (aka gobo) can be purchased at natural food stores and farmers' markets. It has an earthy, mildly bitter taste and can be eaten raw like a carrot once the brown outer layer is peeled away, but is most often sliced and added to a stir-fry. To store, refrigerate it in water in a shallow dish for up to four days.

Many health food stores offer burdock supplements, as well as dried root powder, tinctures, and liquid extracts.

There is limited clinical evidence to guide burdock dosing. Dosages used in studies vary from 200 milligrams of burdock root extract to six grams a day of burdock root tea. A 28-day phase I dose-determination trial conducted in patients with advanced refractory pancreatic cancer recommended 12 grams a day.

It's important to keep in mind that supplements haven't been tested for safety and dietary supplements are largely unregulated. In some cases, the product may deliver doses that differ from the specified amount for each herb. In other cases, the product may be contaminated with other substances such as metals. Also, the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

Possible Side Effects

Burdock root is generally regarded as safe, however, some people should avoid it. For instance, people with diabetes who take blood-sugar lowering medicines should not use burdock root as it may cause hypoglycemia. Burdock has been used traditionally as a diuretic to increase urine output and taking additional diuretics while using it isn't recommended as it may cause dehydration. Burdock may also trigger an allergy in people sensitive to daisies, chrysanthemums, or ragweed. Discontinue use and see your healthcare provider if you suspect an allergic reaction. If you have a sensitivity to foods high in inulin (such as artichokes, asparagus, or leeks), you may experience temporary gas or bloating after eating burdock root. Avoid use if you're pregnant, as the herb has been reported to stimulate the uterus and possibly cause premature labor.