Research review
Burdock root: what the research does and doesn't show
A map of the burdock research: two controlled trials of the root itself, three of tea or extract, and several blend or topical studies.
The research does not support burdock root as a treatment for any condition. Only two controlled trials gave people burdock root itself, one in women with polycystic ovary syndrome and one in adults with knee osteoarthritis, and both measured blood markers, not symptoms. The other human studies used extracts, tea of unstated plant part, blends, or applied it to skin.
What the evidence doesn't support
It does not support burdock root for the liver, kidneys, skin, blood pressure or blood sugar. It does not support the traditional idea that it "detoxifies" the blood, which a 2011 review describes as a traditional-Chinese-medicine concept, not a measured effect (PMID 20981575). It does not support crediting burdock for results from blends such as a four-herb mix or a seven-ingredient supplement, or from burdock fruit, seed or leaf, which are different parts of the plant. And it does not support any dose, because the amounts studied ranged from 460 mg of root powder to about 6 g of root as tea. For the narrative, see burdock root benefits: what the research does and doesn't show; this page is the inventory.
What the trials found
We searched PubMed on 2 October 2026 for burdock, Arctium lappa and arctigenin with trial, case-report and observational filters, and read every abstract below. Certainty is for the question "did burdock change this outcome in this group".
| Study | Population | Dose and form | Duration | Result | Certainty |
|---|---|---|---|---|---|
| Burdock root, swallowed | |||||
| PMID 41757842 (2026) | 60 women with polycystic ovary syndrome, one centre in Iran | 460 mg a day root powder versus placebo | 12 weeks | Antioxidant enzymes rose; malondialdehyde, C-reactive protein and ovarian volume fell versus placebo | Low: single small trial, blood markers |
| PMID 25350500 (2016) | 36 adults aged 50-70 with knee osteoarthritis, all on standard medication | Three 2 g cups a day of root tea (about 6 g root) versus boiled water | 42 days | Lower IL-6, hs-CRP and malondialdehyde and higher antioxidant capacity versus water | Low: blood markers, not pain or function |
| Burdock tea or extract, plant part unstated or combined with exercise | |||||
| PMID 31043657 (2019) | 161 patients newly diagnosed with diverticular bleeding (91) or acute diverticulitis (70) | 1.5 g of burdock tea three times a day versus no treatment | Median 22 and 30 months | Fewer repeat diverticulitis episodes (5 of 47 versus 14 of 44); no difference for bleeding | Low: open-label, no placebo; plant part not stated |
| PMID 36295873 (2022) | 42 older women with metabolic syndrome | Burdock extract, dose not stated, alone or with aqua exercise | 16 weeks | Exercise improved insulin resistance; extract plus exercise improved arterial-stiffness measures | Low: cannot isolate burdock |
| PMID 33664334 (2021) | Elderly women with metabolic syndrome | Burdock root extract, dose not stated, alone or with aqua exercise | Not stated in abstract | Hormone-binding globulin and estradiol rose with extract; DHEA-S rose only with extract; no combined benefit | Low |
| Blends containing burdock (cannot be attributed to it) | |||||
| PMID 29520881 (2018) | 36 adults with H. pylori infection | Complex of burdock, angelica, gromwell and sesame oil versus placebo | 8 weeks | Breath-test value and inflammatory markers were lower than with placebo | Low: four ingredients |
| PMID 29058588 (2017) | 24 healthy volunteers, no control group | Seven-ingredient supplement containing burdock seed, twice daily | 4 weeks | Several inflammatory gene signals fell | Very low: seed, not root; many ingredients |
| PMID 17212569 (2006) | 510 women with breast cancer; retrospective | About 43.6 mL a day of a four-herb blend that includes burdock root | Retrospective | No clear difference in quality-of-life or mood scores; two subscales were slightly worse in users | Very low |
| Other plant parts, skin application and homeopathy (not burdock root swallowed) | |||||
| PMID 19146605 (2008) | Volunteers; number not stated in the abstract | Fruit extract in a skin formulation | 4 to 12 weeks | Skin collagen and hyaluronan markers and wrinkle volume were reported to change versus vehicle | Low: topical fruit extract |
| PMID 24668061 (2014) | 5 Amish people with minor burns | Burdock leaf dressing plus a multi-herb ointment | Healing under 14 days on average | Little pain at dressing changes; no infection | Very low: five people, topical leaf |
| PMID 24931753 (2014) | 34 people with acne (32 completed) | Homeopathic Lappa, 6c to 1M potencies | 6 months | Lesion counts fell; uncontrolled | Very low: not burdock root |
| Safety report and reviews | |||||
| PMID 36636365 (2022) | One 36-year-old woman | Six-herb liver "detox" tea containing burdock root | Not stated in abstract | Acute cholestatic liver injury; with six ingredients the cause cannot be pinned on burdock | One case |
| PMID 41750986 (2026) | Narrative review of blood-sugar research | Not applicable | 2000-2025 literature | Effects shown in animal and cell models; limited clinical data; a gap in randomised trials in diabetes | Not a trial |
| PMID 41111517 (2025) | Critical review in immune-mediated skin conditions | Not applicable | To July 2025 | Mostly cell and mouse data; no robust randomised trials | Not a trial |
Where the evidence is, and isn't
Five controlled studies gave people burdock root, tea or extract: two of the root itself, one open-label tea trial, and two extract-and-exercise trials in older women with metabolic syndrome. All were in people with a condition, and most measured blood markers. None tested healthy adults, and we found no repeat of any of them. There is nothing on liver, kidneys or blood pressure. Whether the root powder or tea works the same way as an extract is unknown. See burdock root side effects and burdock root and medications.
Questions people ask
Can burdock root cause diarrhea?
None of the abstracts we read reports diarrhea, so we cannot say whether or how often it happens. The adverse effects reviewers flag for burdock are contact dermatitis and other allergic or inflammatory reactions (PMID 20981575), plus one liver-injury report involving a six-herb tea. If you get diarrhea, a rash or swelling after a new supplement, stop and ask a doctor or pharmacist.
Is burdock root safe during pregnancy or while breastfeeding?
We found no study of burdock root in pregnancy or breastfeeding, so we cannot call it safe, and this page gives no guidance on either. Ask a doctor first.
When to talk to a doctor
Burdock root is not a treatment for polycystic ovary syndrome, osteoarthritis, diverticular disease, diabetes or any other condition. If you have one of them, talk to your doctor before adding it, particularly if you take medication. Stop and get advice if you develop a rash, itching or swelling, which can be an allergic reaction; see who should not take burdock root.
Sources
- A review of the pharmacological effects of Arctium lappa (burdock) A 2011 review of burdock notes its traditional uses and warns that it can cause contact dermatitis and other allergic or inflammatory reactions.
- Effects of Arctium lappa L. Root Powder on Some Markers of Oxidative Stress and Inflammation in Women with Polycystic Ovary Syndrome: A Randomized, Double-Blind Controlled Clinical Trial Study In 60 women with PCOS, 460 mg a day of burdock root powder for 12 weeks shifted oxidative-stress and inflammation markers versus placebo.
- Effects of Arctium lappa L. (Burdock) root tea on inflammatory status and oxidative stress in patients with knee osteoarthritis In 36 adults with knee osteoarthritis, 6 g a day of burdock root as tea for 6 weeks shifted blood inflammation and oxidative-stress markers.
- Effects of Burdock tea on recurrence of colonic diverticulitis and diverticular bleeding: An open-labelled randomized clinical trial In an open-label trial with no placebo, 1.5 g of burdock tea three times a day was followed by fewer repeat diverticulitis episodes but no difference in diverticular bleeding.
- The Combined Intervention of Aqua Exercise and Burdock Extract Synergistically Improved Arterial Stiffness: A Randomized, Double-Blind, Controlled Trial In 42 older women with metabolic syndrome, burdock extract combined with aqua exercise improved arterial-stiffness measures beyond exercise alone over 16 weeks.
- Exercise training and burdock root (Arctium lappa L.) extract independently improve abdominal obesity and sex hormones in elderly women with metabolic syndrome In older women with metabolic syndrome, burdock root extract was followed by higher SHBG, estradiol and DHEA-S levels; the abstract gives no dose.
- Beneficial effect of Burdock complex on asymptomatic Helicobacter pylori-infected subjects: A randomized, double-blind placebo-controlled clinical trial In 36 adults with H. pylori, a four-ingredient burdock complex for 8 weeks was followed by lower breath-test values than placebo; burdock cannot be separated out.
- Effect of Infla-Kine supplementation on the gene expression of inflammatory markers in peripheral mononuclear cells and on C-reactive protein in blood A 2017 open trial (no placebo comparison) found several inflammation-related gene markers in blood cells, and a marker called CRP, were lower in 24 healthy adults after 4 weeks of a five-ingredient supplement containing papaya enzyme than before starting it; participants also reported general well-being improvements, most often around muscle and joint discomfort. With five active ingredients and no placebo group, papain's own contribution can't be determined from this trial.
- Trial of Essiac to ascertain its effect in women with breast cancer (TEA-BC) In 510 women with breast cancer, a four-herb blend that includes burdock root did not clearly change quality-of-life or mood scores; burdock can't be isolated.
- Natural Arctium lappa fruit extract improves the clinical signs of aging skin A skin-cream study used a burdock fruit extract applied to skin; it is not about swallowing burdock root.
- The effect of Burns & Wounds (B&W)/burdock leaf therapy on burn-injured Amish patients: a pilot study measuring pain levels, infection rates, and healing times A five-person case series used burdock leaves on burns together with an ointment; it is a topical leaf use and says nothing about swallowing burdock root.
- Observational study of Arctium lappa in the treatment of acne vulgaris A small uncontrolled study of homeopathic burdock (6c to 1M potencies, not root) in 34 people with acne reported improvement; the authors say controlled trials are needed.
- Drug-Induced Liver Injury from Herbal Liver Detoxification Tea One woman had liver injury after a six-herb tea that included burdock root; which ingredient was responsible is not known.
- Unveiling the Antihyperglycemic Potential of Arctium lappa L. (Asteraceae): Traditional Application, Phytochemistry, and Molecular Insights A 2026 review found burdock's blood-sugar effects come mainly from cell and animal studies and called for randomised trials in people.
- Immunopharmacological potential of Arctium lappa L. in immune-mediated skin diseases: A critical review of experimental and clinical evidence A 2025 review found burdock's effects on skin-related immune pathways rest mostly on cell and mouse studies, with no robust randomised trials in people.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.