Burdock

Burdock root is described as a blood purifier, believed to clear toxins from the blood ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}. It has been used for rheumatism and gout, and as a diuretic and diaphoretic, to promote urine and sweating ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}.

For the skin, the root has been used for eczema, seborrhoeic eczema, acne and poorly healing wounds, taken internally or applied as a wash ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}. It was also taken for loss of appetite and digestive complaints, and as a laxative ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}.

The EU recognises traditional use of the root to increase urine flow in minor urinary complaints, for temporary loss of appetite, and for seborrhoeic skin conditions ^{35Reference 35European Medicines Agency · 2010ReviewCommunity herbal monograph on Arctium lappa L., radix — regulatory monographView study →}.

In Chinese medicine the fruit (niu bang zi) is the main part used. It is used to dispel wind-heat, to relieve sore throat, to promote the eruption of rashes, and to clear toxins ^{4,37Reference 4Zhao et al. · 2009In vitroIn vitro anti-inflammatory effects of arctigenin, a lignan from Arctium lappa L., through inhibition on iNOS pathway — in vitroView study →Reference 37Jin et al. · 2023Systematic reviewA systematic review on botany, ethnopharmacology, quality control, phytochemistry, pharmacology and toxicity of Arctium lappa L. fruit — reviewView study →}.

It is traditionally given for colds with fever, cough and breathlessness, and sore throat ^{37Reference 37Jin et al. · 2023Systematic reviewA systematic review on botany, ethnopharmacology, quality control, phytochemistry, pharmacology and toxicity of Arctium lappa L. fruit — reviewView study →}. It has also been used for measles, mumps and boils ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}.

The root is used in Chinese medicine to “detoxify” the blood and for skin diseases such as eczema ^{1Reference 1Chan et al. · 2011ReviewA review of the pharmacological effects of Arctium lappa (burdock) — reviewView study →}.

In a 42-day randomized controlled trial, 36 patients with knee osteoarthritis took three cups a day of root tea (2 g root in 150 mL water) on top of standard acetaminophen and glucosamine. Compared with a hot-water control, they had significant falls in serum IL-6, high-sensitivity C-reactive protein and malondialdehyde ^{3Reference 3Maghsoumi-Norouzabad et al. · 2016RCTEffects of Arctium lappa L. (Burdock) root tea on inflammatory status and oxidative stress in patients with knee osteoarthritis — randomised controlled trialView study →}.

In stimulated macrophages, arctigenin suppressed nitric oxide, TNF-α and IL-6 by inhibiting inducible nitric oxide synthase. It did not affect COX-2 ^{4Reference 4Zhao et al. · 2009In vitroIn vitro anti-inflammatory effects of arctigenin, a lignan from Arctium lappa L., through inhibition on iNOS pathway — in vitroView study →}.

In mice, arctigenin reduced experimental colitis, where it and not its glycoside arctiin was the effective constituent of the fruit ^{5Reference 5Wu et al. · 2014AnimalArctigenin but not arctiin is the major effective constituent of Arctium lappa fruit for attenuating colitis — animal modelView study →}. It also reduced inflammation in thioglycollate-induced peritonitis ^{6Reference 6Zhao et al. · 2020AnimalArctigenin protects mice from thioglycollate-induced acute peritonitis — mouse in vivoView study →}.

Gap: the human data are one trial of 36 patients in one condition over 42 days, with no dose-finding and no replication.

A purified fructan from burdock root scavenged hydroxyl radicals in vitro and raised antioxidant enzyme activity while lowering malondialdehyde in aging mice ^{7Reference 7Liu et al. · 2014In vitroIn vitro and in vivo antioxidant activity of a fructan from the roots of Arctium lappa L. — in vitro and mouse in vivoView study →}. Other root polysaccharide fractions scavenged free radicals in vitro ^{8Reference 8Jiang et al. · 2019In vitroExtraction and antioxidant activities of polysaccharides from roots of Arctium lappa L. — in vitroView study →}.

In the knee-osteoarthritis trial, root tea also significantly raised total antioxidant capacity and superoxide dismutase activity ^{3Reference 3Maghsoumi-Norouzabad et al. · 2016RCTEffects of Arctium lappa L. (Burdock) root tea on inflammatory status and oxidative stress in patients with knee osteoarthritis — randomised controlled trialView study →}.

The human antioxidant data come from that single trial. The rest is in vitro or animal work on purified polysaccharide fractions rather than the tea people drink.

Burdock extract protected mouse livers against carbon tetrachloride and acetaminophen, reversing falls in glutathione and cytochrome P-450 ^{9Reference 9Lin et al. · 2000AnimalHepatoprotective effects of Arctium lappa on carbon tetrachloride- and acetaminophen-induced liver damage — mouse in vivoView study →}. In rats given chronic ethanol plus carbon tetrachloride, oral root extract at 300 mg/kg three times a day restored glutathione and cytochrome P-450 and lowered serum transaminases ^{10Reference 10Lin et al. · 2002AnimalHepatoprotective effects of Arctium lappa Linne on liver injuries induced by chronic ethanol and CCl4 — rat in vivoView study →}. A root extract also protected rat livers against cadmium ^{11Reference 11de Souza Predes et al. · 2015AnimalHepatoprotective effect of Arctium lappa root extract on cadmium toxicity in adult Wistar rats — rat in vivoView study →}.

The authors attributed the effect mainly to antioxidant activity. The doses used in rats are far above any culinary or tea exposure.

This is the largest body of burdock-related research, and almost all of it concerns isolated arctigenin. In a screen of 500 Kampo medicinal plant extracts, arctigenin was identified as the compound in A. lappa that selectively kills cancer cells deprived of nutrients. It also suppressed pancreatic tumour growth in mice ^{21Reference 21Awale et al. · 2006In vitroIdentification of arctigenin as an antitumor agent able to eliminate cancer-cell tolerance to nutrient starvation — in vitro and animalView study →}.

Later cell and animal studies report activity against breast cancer through GM-CSF, STAT3 and β-catenin signaling ^{22Reference 22Shi et al. · 2020In vitroArctigenin attenuates breast cancer progression through decreasing GM-CSF/TSLP/STAT3/β-catenin signaling — in vitro and animalView study →}, and a review describes activity across many other cancer types ^{23Reference 23Shabgah et al. · 2021ReviewArctigenin, an anti-tumor agent — reviewView study →}.

Gap: these are purified-compound studies at pharmacological concentrations. The whole herb has never been tested as an anticancer agent.

A hydro-alcoholic root extract lowered glucose and triglycerides in type 2 diabetic mice ^{12Reference 12Ahangarpour et al. · 2017AnimalAntidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root extract in type 2 diabetic mice — animal modelView study →}. A root polysaccharide improved lipid levels in diabetic rats through the PKC/NF-κB pathway ^{13Reference 13Li et al. · 2019AnimalRegulation of lipid metabolism in diabetic rats by Arctium lappa L. polysaccharide through the PKC/NF-κB pathway — rat in vivoView study →}.

Arctigenin improved insulin resistance through the IRS2/GLUT4 pathway in diabetic mice ^{14Reference 14Zhou et al. · 2023AnimalArctigenin mitigates insulin resistance by modulating the IRS2/GLUT4 pathway via TLR4 in type 2 diabetes — animal modelView study →}. In mice on a high-fat diet it increased short-chain-fatty-acid-producing gut bacteria and improved glucose and lipid metabolism ^{15Reference 15Wang et al. · 2024AnimalArctigenin ameliorates high-fat diet-induced metabolic disorders by reshaping gut microbiota — mouse in vivoView study →}.

The root’s inulin is a fermentable fibre that feeds gut bacteria ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}.

No human glycemic trial of burdock exists; every endpoint here is from rodents.

Arctigenin reduced brain injury in rats after stroke-like ischemia-reperfusion by suppressing microglial activation and inflammatory cytokines ^{28Reference 28Fan et al. · 2012AnimalArctigenin protects focal cerebral ischemia-reperfusion rats through inhibiting neuroinflammation — rat in vivoView study →}. It limited cortical hyperactivity and eased symptoms in experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis ^{27Reference 27Wei et al. · 2021AnimalArctigenin exerts neuroprotective effect by ameliorating cortical activities in experimental autoimmune encephalomyelitis — mouse in vivoView study →}. Repeated doses produced antidepressant- and anxiolytic-like effects in mice ^{29Reference 29Du et al. · 2019AnimalRepeated arctigenin treatment produces antidepressant- and anxiolytic-like effects in mice — mouse in vivoView study →}.

All of this is isolated-compound work in rodents.

Leaf extracts of burdock inhibited organisms found in root-canal infections, including Enterococcus faecalis, Staphylococcus aureus and Candida albicans ^{17Reference 17Pereira et al. · 2005In vitroAntimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections — in vitroView study →}. An A. lappa fraction used as a root-canal dressing stopped bacterial growth in extracted teeth by 14 days ^{18Reference 18Gentil et al. · 2006In vitroIn vitro evaluation of the antibacterial activity of Arctium lappa as a phytotherapeutic agent used in intracanal dressings — in vitroView study →}.

Isolated arctigenin disrupted the membrane of Pseudomonas aeruginosa, reduced its biofilm and virulence, and protected infected mice ^{20Reference 20Koshak et al. · 2024In vitroArctigenin from burdock root exhibits potent antibacterial and anti-virulence properties against Pseudomonas aeruginosa — in vitro and mouse in vivoView study →}.

Low-molecular-weight peptides from burdock root were active against acne bacteria in vitro and were not toxic to skin cells ^{19Reference 19Miazga-Karska et al. · 2020In vitroAnti-acne action of peptides isolated from burdock root — in vitro and pilot testingView study →}.

All of it is laboratory work, at concentrations that may not be reached from normal preparations.

A pilot case series followed five Amish patients with first- and second-degree burns, treated with a multi-herb “Burns & Wounds” ointment dressed with burdock leaves. Dressing changes caused little or no pain, none of the burns became infected, and healing took under 14 days on average ^{24Reference 24Kolacz et al. · 2014ObservationalThe effect of Burns & Wounds (B&W)/burdock leaf therapy on burn-injured Amish patients — pilot study (observational)View study →}.

The ointment contains honey, aloe, comfrey, wormwood, white oak bark and other ingredients, and there was no control group ^{24Reference 24Kolacz et al. · 2014ObservationalThe effect of Burns & Wounds (B&W)/burdock leaf therapy on burn-injured Amish patients — pilot study (observational)View study →}.

A burdock-polysaccharide hydrogel sped wound healing in diabetic rats ^{25Reference 25Xiang et al. · 2025AnimalInjectable Arctium lappa polysaccharide-based composite hydrogel enhances diabetic wound healing — animal modelView study →}, and arctiin protected human skin fibroblasts from UVB damage in vitro ^{26Reference 26Lee et al. · 2014In vitroArctiin induces a UVB protective effect in human dermal fibroblast cells through microRNA expression — in vitroView study →}.

Gap: the one human study tests a multi-herb ointment with burdock leaf in five uncontrolled cases. Burdock’s own contribution cannot be separated out, and the root is not involved.

Intranasal arctigenin reduced lung consolidation and prolonged survival in influenza-infected mice ^{30Reference 30Yang et al. · 2005AnimalEffect of anti-influenza virus of arctigenin in vivo — animal modelView study →}.

Arctiin and arctigenin from the fruit were active against influenza A in vitro. Oral arctiin was effective in infected mice, including immunocompromised mice, though less so than oseltamivir ^{31Reference 31Hayashi et al. · 2010AnimalTherapeutic effect of arctiin and arctigenin in influenza A-infected mice — mouse in vivoView study →}.

In cell culture, arctigenin reduced chikungunya virus entry and replication, but had no effect on dengue virus ^{32Reference 32Shukla et al. · 2024In vitroArctigenin from Arctium lappa L. inhibits chikungunya virus by affecting its entry and replication — in vitroView study →}.

No human antiviral data exist.

Contamination. Burdock root tea has caused atropine-like (anticholinergic) poisoning. Atropine is not a constituent of burdock; analysis showed the tea was contaminated with a source of solanaceous alkaloids, possibly belladonna root ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}. Substitution with comfrey or broad-leaved dock root has also been reported ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}. Buy from a supplier who tests identity.

Allergy. Burdock should not be taken by anyone allergic to plants of the daisy family (Asteraceae) ^{35Reference 35European Medicines Agency · 2010ReviewCommunity herbal monograph on Arctium lappa L., radix — regulatory monographView study →}. One case of anaphylactic shock was reported in a man who had eaten boiled burdock root ^{36Reference 36European Medicines Agency · 2010Assessment report on Arctium lappa L., radix — regulatory assessmentView study →}.

Digestion. The root is rich in inulin, a fermentable fibre, and large amounts can cause bloating, wind or loose stools.

Blood sugar. Root extract lowered blood glucose in diabetic mice, and a root polysaccharide improved lipids in diabetic rats ^{12,13Reference 12Ahangarpour et al. · 2017AnimalAntidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root extract in type 2 diabetic mice — animal modelView study →Reference 13Li et al. · 2019AnimalRegulation of lipid metabolism in diabetic rats by Arctium lappa L. polysaccharide through the PKC/NF-κB pathway — rat in vivoView study →}. Burdock may add to the effect of antidiabetic drugs, so blood sugar should be monitored if they are combined.

Diuretics. The EU monograph does not recommend taking burdock with prescription diuretics ^{35Reference 35European Medicines Agency · 2010ReviewCommunity herbal monograph on Arctium lappa L., radix — regulatory monographView study →}.

Children. Use under 18 is not recommended, for lack of data ^{35Reference 35European Medicines Agency · 2010ReviewCommunity herbal monograph on Arctium lappa L., radix — regulatory monographView study →}.