burdock root side effects

Documented problems with burdock are uncommon and mostly case reports: allergic reactions, one case of very low platelets after a herbal tea containing burdock and yellow dock, and one case of liver injury after a six-herb tea containing burdock root. In each, burdock's role is unproven. A separate concern is the identity of raw root.

Allergic reactions

Burdock belongs to the daisy family (Asteraceae), the same family as ragweed, chrysanthemums and marigolds. A 2011 review of burdock's pharmacology says burdock can cause side effects including contact dermatitis and other allergic or inflammatory responses, and a 1995 case report is titled "Allergic contact dermatitis due to burdock" (we verified the title only, and it involved skin contact, not swallowing). We did not find data on oral cross-reactivity between burdock and other daisy-family plants, so the cautious reading is that anyone allergic to related plants should ask a clinician first. See who should not take burdock root.

Two case reports with herbal teas

A 2022 case report describes a 38-year-old woman whose platelet count was 5 K/µl (very low) one week after she drank an herbal tea containing yellow dock and burdock; the authors say the association between these herbs and immune thrombocytopenia needs further research. A second 2022 report describes a 36-year-old woman with acute liver injury after an over-the-counter herbal "liver detox" tea containing burdock root, stinging nettle, cleavers, dandelion root, lemon peel and lemon myrtle; the authors called it the first report of liver toxicity from any of those ingredients.

In both cases several herbs were present, one person each was involved, and nothing proves burdock was responsible. They are the sort of rare events case reports exist to flag, and they are a reason to tell your clinician about any herbal product you take, particularly if you have a bleeding or liver problem.

Root identity

A 1953 Italian report is titled "Atropine poisoning by ingestion of decoction of burdock roots". We read only the title and citation, so we can't say what caused it. Atropine is associated with other plants rather than with burdock, which makes mix-up or contamination of raw root the obvious thing to rule out, and is why the identity of the plant matters. In practice: don't forage root unless an experienced person identifies the plant, and for supplements, look for a product that names Arctium lappa and the plant part; see how to choose a good burdock root.

What the trials reported

The abstracts of the two human trials (460 mg a day of root powder for 12 weeks, and about 6 g a day of root as tea for six weeks) report no side-effect data either way. That is not the same as showing there were none. We found no long-term safety data.

Questions people ask

What are the side effects of burdock root tea?

The documented ones are allergic reactions and two case reports involving multi-herb teas. Nothing in the trial abstracts quantifies side effects, so we give no frequency.

What are the risks of burdock root?

Allergy in people sensitive to daisy-family plants, rare case reports with herbal teas, and identity or contamination of raw root. See burdock root and medications: what to check for the medication side.

Does burdock root as a food, like the Korean side dish, carry the same risks?

Burdock root has a long history as a vegetable, and the case reports here involve teas and supplements. Allergy to the plant is relevant in any form, though.

What should make me stop and see a clinician?

A rash, itching or swelling, unusual bruising or bleeding, or yellowing of the skin or eyes while taking a burdock product.