Dandelion
Summary
Dandelion has almost no human research. NCCIH says there is no compelling scientific evidence for any health use. The only clinical data we found is a one-day pilot in 17 people, where a fresh-leaf extract increased how often they urinated (grade D). Food amounts are considered likely safe; allergy to related plants and interactions with water pills, diabetes drugs and blood thinners are possible.
Key facts
- A plant in the daisy family (Asteraceae); leaf, flower and root are used as food and in herbal products[1][3]
- Urine output: more frequent urination after a fresh-leaf extract in a 17-person, one-day pilot with no placebo (D)[2]
- 8 mL of fresh-leaf hydroethanolic extract three times in one day; no trial of root capsules or tea[2]
- NCCIH: very little research and no compelling evidence for any health condition[1]
- None set; dandelion is a herb, not a nutrient[1]
- Theoretical, per NCCIH: diabetes drugs, anticoagulants and antiplatelets, and water pills[1]
- 1 graded human outcome on this page
- October 10, 2026
How it works
ProposedLab studies report antioxidant and anti-inflammatory activity from dandelion's phenolic compounds and sesquiterpene lactones. Its traditional use as a diuretic is the only effect with any human data, and how it would work is not established.[3][1]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Urination frequency and urine volume relative to fluid intake | Mixed | Grade D | Open-label trial · n = 17 · 2009 Healthy volunteers (US) Form: Fresh-leaf hydroethanolic extract · Dose: 8 mL three times in one day · Duration: 1 day (plus 2 baseline days and 1 follow-up day) Urination frequency rose in the 5 hours after the first dose and the urine-to-fluid ratio rose after the second dose; the third dose changed nothing. | 19678785 (opens PubMed)Source [2] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Dandelion leaf extract or tincture | Varies[2] | No human absorption data in our sources.[2] | The pilot abstract does not report adverse events; one day of use tells us little about tolerance.[2] | Diuretic pilot (8 mL three times in one day) |
| Dandelion root (capsules, tea, roasted "coffee") | Varies[1] | No human absorption data in our sources.[1] | Food amounts are considered likely safe; larger amounts are less studied.[1] | Not tested in any human trial we found |
| Dandelion greens (food) | Varies[1][3] | Eaten as a vegetable in many countries.[3] | Likely safe in food amounts.[1] | Not tested as a supplement |
Studied doses
Doses studied in human trials ranged from a single pilot's 8 mL of fresh-leaf extract, given three times over one day. No trial has tested dandelion root capsules, tea or longer use, so no studied dose exists for most products.[2]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Water pills (diuretics)NIH fact sheetNCCIH lists a theoretical interaction; dandelion is used as a diuretic and could add to their effect.[1]
- Diabetes drugsNIH fact sheetNCCIH lists a theoretical interaction; one emergency-medicine case report describes low blood sugar attributed to dandelion.[1][5]
- Anticoagulants and antiplatelet drugsNIH fact sheetNCCIH lists a theoretical interaction; no human interaction studies exist.[1]
Who should be careful
- Allergy to daisy-family plants
- Patch tests confirm dandelion contact allergy in sensitized people, and NCCIH notes conflicting evidence on cross-reactions in people sensitive to ragweed, chrysanthemums, marigolds or daisies.[1][4]
- Eczema (atopic dermatitis)
- NCCIH notes topical dandelion may cause allergic reactions in people with atopic dermatitis.[1]
- Pregnancy and breastfeeding
- Safety of amounts above food levels is not known.[1]
- People on water pills, diabetes drugs or blood thinners
- Interactions are theoretical but untested; check with your prescriber first.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Safety
Food amounts are considered likely safe; supplement-level safety is largely unstudied.
- Allergy
- Contact dermatitis from dandelion is documented by patch testing, and 5 of 7 people with dandelion dermatitis were missed by the standard sesquiterpene lactone screening mix.[4]
- Case reports
- Published single-patient reports include low blood sugar after dandelion ingestion and digital necrosis linked to dandelion tea; causation was not established.[5][6]
- Evidence gap
- A 2026 systematic review of the Taraxacum genus summarizes mostly laboratory and animal pharmacology and toxicology.[7]
How to read the label
- Label dose vs clinical doseRoot and leaf capsules, teas and roasted root "coffee" have no tested dose. The only trial used a fresh-leaf liquid extract for one day.[1][2]
- Root and leaf are different productsThe diuretic pilot used leaf extract; root products are mostly promoted for digestion and have no human trial data.[1][2]
- "Liver detox" claimsLiver-protection claims come from lab and animal work, not human trials.[3][1]
Frequently asked questions
Does dandelion work as a diuretic?
One 17-person pilot found more frequent urination for a few hours after a fresh-leaf extract, with no placebo group. That is very preliminary.[2]
Is dandelion good for the liver?
Liver claims come from lab and animal studies. NCCIH finds no compelling evidence for any health use in people.[1][3]
Is dandelion root tea safe?
Food amounts are considered likely safe. Larger supplement amounts are less studied, and people allergic to daisy-family plants may react.[1][4]
Can dandelion interact with medications?
NCCIH lists theoretical interactions with water pills, diabetes drugs and blood thinners. Ask your prescriber before using it with these.[1]
How much dandelion is used in studies?
Only one human trial: 8 mL of fresh-leaf extract three times in one day. There is no studied dose for root capsules or tea.[2]
Sources
- [1]Dandelion: Usefulness and Safety (last updated November 2024). NIH National Center for Complementary and Integrative Health, 2024. fact-sheet
- [2]The diuretic effect in human subjects of an extract of Taraxacum officinale folium over a single day.. J Altern Complement Med, 2009. open-label
- [3]Diverse biological activities of dandelion.. Nutr Rev, 2012. review
- [4]Dandelion dermatitis.. Contact Dermatitis, 1991. observational
- [5]First report of hypoglycemia secondary to dandelion (Taraxacum officinale) ingestion.. Am J Emerg Med, 2010. observational
- [6]Digital necrosis from dandelion tea.. Br J Dermatol, 2013. observational
- [7]Unveiling the genus Taraxacum: From folk medicine to chemodiversity-driven pharmacological and toxicological outcomes-A systematic review.. J Ethnopharmacol, 2026. systematic-review
What changed
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Adversarial review pass: the single evidence row re-read against its PubMed abstract (n=17, no placebo, third dose null). Safety and interaction statements taken from the NCCIH fact sheet (opened 2026-10-10, last updated November 2024). Case reports without abstracts are cited by title only, with causation not asserted. Retraction, expression-of-concern and erratum check run on all 6 PMIDs via PubMed records: none flagged. No cost-per-dose block, because no trial used a milligram dose. Page set indexable.