Contra-Indications of Burdock

According to Peirce, “As a food, Burdock root is generally considered safe. But very spotty information is available on it potential toxicity when used in medicinal concentrations. The FDA classifies it as an herb of “undefined safety.” Contact with the plant can cause skin irritation or contact dermatitis, due to the lactones in the plant leaf. If you are pregnant or diabetic, you may want to avoid the herb; evidence that is may stimulate the uterus raises concerns about miscarriage (although miscarriage has never been documented), and studies in mice indicate that it can aggravate a diabetic condition.” (123) Another caution is that burdock may increase the instances of heartburn or sour stomach, due to its ability to promote digestive secretions and acid production. “If you have ulcers, an irritable bowel, or excessive stomach acid, burdock may worsen your condition…Avoid burdock, or any substance that increases stomach acid, during a bout of diarrhea, ulcer flare-up, or case of heartburn.” (Brett) A warning published by one medical doctor states that, “Large doses of medicinal preparations containing burdock may cause the level of potassium in the blood to drop too low…Burdock has been reported to interact with medications given to control diabetes. Persons with diabetes should consult a physician before taking any herbal preparation containing burdock. In addition, burdock has been reported to intensify the activity of diuretics (drugs given to increase urine output) and lithium. Burdock may also interfere with the absorption of iron and other minerals in the diet. Persons who must take supplemental iron or other dietary minerals should consult their health practitioner before taking burdock.”(Frey) Another admonition is that “excessive use may precipitate a symptomatic crisis in severely toxic conditions or where eliminatory channels are deficient. Dosage should be cautious initially and gradually increased.” (Burdock.2) Care should be taken when harvesting burdock leaves, as they can often times resemble those of rhubarb, which is toxic to humans when eaten. An additional website sited medication/burdock interactions that should be avoided. It states, “Allergy to burdock may occur in individuals with allergy to members of the Asteraceae/Compositae family including ragweed, chrysanthemums, marigolds, and daisies. Severe allergic reactions (anaphylaxis) have been associated with burdock. Allergic skin reactions have been associated with the use of burdock plasters on the skin. Caution should be used in patients with allergies or intolerance to pectin since certain parts of the burdock plant contains different levels of pectin complex…Diuretic effects (increasing urine flow) and estrogen-like effects have been reported with oral burdock use in patients with HIV. Although reports of symptoms such as dry mouth and slow heart rate have been noted in people taking burdock products, it is believed that contamination with belladonna may be responsible with these actions…In theory, tannins present in burdock may be toxic, although toxicity has not been reported in animal studies. Tannins can cause stomach upset, and in high concentrations my result in kidney or liver damage. Long-term use of tannins may increase the risk of head and neck cancers, although this has not been seen in humans…Based on animal studies that show components of burdock to cause uterus stimulation, burdock is sometimes recommended to be avoided during pregnancy…Burdock has been associated with diuretic effects (increasing urine flow) in one human report, and in theory may cause excess fluid loss (dehydration) or electrolyte imbalances (for example, changes in potassium or sodium levels in the blood). These effects may be increased when burdock is taken at the same time as diuretic drugs such as chlorothiazide (Diuril®), furosemide (Lasix®), hydrochlorothizide (HCTZ), or spironolactone (Aldactone®). Based on limited himan evidence that is not entirely clear, burdock may have estrogen-like properties, and may act to increase the effects of estrogenic agents including hormone replacement thereapies such as Premarin® or birth control pills. Based on animal research, burdock may increase the risk of bleeding when taken with drugs that increase the risk of bleeding (although human research is lacking). Some examples include aspirin, anticoagulants (“blood thinners”) such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). Tinctures of burdock may contain high concentrations of alcohol (ethanol), and may lead to vomiting if used with disulfiram (Antabuse®) or metronidazole (Flagyl®).” (Burdock.4) In researching this plant, and its medicinal properties, I have found very little in the way of human research and studies. It seems that there is a lot of speculation as to what the chemical components in this plant can or cannot do, but there is very little hard evidence. These precautions should be considered. As with all herbs, and medicines for that matter, use with prudence and seek the advice with someone skilled in their use and administration.