Kuan Dong Hua (Coltsfoot Flower)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Kuan Dong Hua?

  Standard reference ranges are 5–10 grams in decoction (Chen) and 4.5–9 grams in decoction (Bensky) — the figures our own record already carries, and consistent across materia medica sources. These are reference figures for a herb that carries a real pyrrolizidine-alkaloid exposure question (see toxicity), so any actual use is a decision for a licensed practitioner rather than something to act on from a page.

  • Quality standard — the Chinese Pharmacopoeia sets a minimum content of 0.07% (w/w) tussilagone, the herb’s principal marker constituent, as its quality-control criterion.
  • The buds, not the leaf — the Chinese material is the unopened flower bud (Farfarae Flos). Much of the European herbal and toxicological literature concerns coltsfoot leaf, which is a different plant part with a different alkaloid profile; the two should not be read as interchangeable when comparing sources.

  Sources: this site’s existing dosage record (Chen and Bensky ranges); PMID 33069788, PMC 7561605, DOI 10.1016/j.jep.2020.113478 (Chinese Pharmacopoeia tussilagone content requirement). Reference facts only — not a prescription.

Chinese Herb Contraindications & Cautions

• Is Kuan Dong Hua safe? Are there cautions?

  Kuan Dong Hua carries two separate cautions: a traditional pattern caution, and a modern constituent caution that is the more consequential of the two. Traditionally it is used with care where cough arises from heat, and where there is lung abscess or pus and blood in the sputum — the cautions our own record already carries. Separately, the plant contains hepatotoxic pyrrolizidine alkaloids, which is why herbal products containing it are subject to regulatory exposure limits in Europe (see the toxicity section below).

  • Caution in heat-type cough — the herb is warm; in a frank heat pattern it works against the pattern.
  • Caution with lung abscess, or pus and blood in sputum — per this site’s existing record.
  • Pyrrolizidine-alkaloid content — senkirkine is the principal alkaloid, with traces of senecionine. These are the same class of compound behind the well-known hepatotoxicity of comfrey and ragwort. This is a constituent fact about the plant, not a statement about any particular product.
  • Regulated, not freely available in every market — PA-containing herbal products are subject to strict daily-exposure limits in Germany and the wider EU, and coltsfoot is one of the specifically named species in that regulatory history.
  • Correct botanical identification matters unusually much here — the single most cited coltsfoot poisoning case turned out not to involve coltsfoot at all, but a misgathered look-alike (see toxicity). Wild-gathered material is where the documented harm sits.

  Sources: this site’s existing caution record for this herb; PMID 19559918, DOI 10.1016/j.talanta.2009.04.028 (senkirkine as the main alkaloid, senecionine in traces); PMID 32413969, PMC 7290370, DOI 10.3390/toxins12050320 (German and EU exposure limits on PA-containing herbal products). Neutral safety reference, not usage instructions.

Chinese Herb Toxicity & Overdose

• The relevant toxicity is not from the herb’s traditional actions but from its pyrrolizidine alkaloids (PAs), principally senkirkine with traces of senecionine. Unsaturated PAs of this class are hepatotoxic, are associated with hepatic veno-occlusive disease (sinusoidal obstruction syndrome), and in the case of coltsfoot are supported by direct animal carcinogenicity data. The picture in the human literature is, however, less clean than it is usually reported — and that is worth stating precisely.

  What is solidly documented:

  • Rodent hepatocarcinogenicity — a 1976 feeding study in inbred ACI rats gave young pre-blooming coltsfoot flowers in the diet. In the highest-dose group, 8 of 12 rats developed haemangioendothelial sarcoma of the liver; 1 of 10 did at the intermediate level and none at the lowest. The authors concluded the carcinogenicity was most probably attributable to senkirkine.
  • Hepatotoxic metabolites in vivo — a 2018 study identified hepatotoxic PA metabolites in rats after administration of Farfarae Flos extract, and the 2021 review of the species reports pathological liver changes and raised liver enzymes after oral administration of water extracts in rats.
  • Regulatory exposure limits (Germany and EU) — from 1992, PA exposure from herbal products in Germany was limited to no more than 1 µg/day for use of up to six weeks and 0.1 µg/day for longer use, with a higher exposure of 10 µg/day specifically accepted for infusions or decoctions of Tussilago farfara. In 2011 the German Federal Institute for Risk Assessment recommended a far tighter daily intake of 0.007 µg/kg body weight (about 0.42 µg for a 60 kg adult), later revised upward roughly threefold. These are the limits that shape what coltsfoot products may legally contain.
  • A PA-free cultivar is being developed — the 2021 review reports that cultivation of a PA-free variety of Tussilago farfara is being developed in Austria, propagated vegetatively.

  The most-cited human case does not say what it is usually said to say. The 1995 report of reversible hepatic veno-occlusive disease in an 18-month-old boy — portal hypertension, severe ascites, centrilobular sinusoidal congestion, after 15 months of daily herbal tea — is routinely cited as a coltsfoot case. The paper itself reports that macroscopic and microscopic analysis of the leaf material showed the parents had actually gathered Adenostyles alliariae (alpine coltsfoot / Alpendost) in place of coltsfoot, the two being easily confused after flowering, and that the major alkaloid found was seneciphylline, not senkirkine. The child recovered fully. Relatedly, a 2020 systematic review of case reports for borage, coltsfoot and comfrey assessed the eleven eligible reports and concluded that failure to establish unequivocally which species was ingested compromised attribution throughout, and that this body of case reports is an unreliable basis for conclusions about the oral safety of coltsfoot. We report this because it is what the primary sources say — not to minimise the alkaloid question, which the animal and regulatory evidence establishes independently.

  Unverified claim, omitted: statements that coltsfoot is outright banned in particular named countries are widely repeated online. We were unable to confirm any specific national prohibition against a resolvable primary source, so we state only the exposure-limit regime documented above rather than name jurisdictions we cannot verify.

  Our own existing note that overdose can cause irritability, restlessness, excitation and increased respiration, and that long-term use may increase liver-cancer risk, is retained; the liver-cancer element corresponds to the rodent data above and should be read as animal evidence, not as a demonstrated human outcome.

  Sources: PMID 1269853 (Gan, 1976: carcinogenic activity of coltsfoot in ACI rats, attributed to senkirkine); PMID 19559918, DOI 10.1016/j.talanta.2009.04.028; PMID 28702943, DOI 10.1002/bmc.4047 (hepatotoxic PA metabolites after Farfarae Flos extract in rats); PMID 33069788, PMC 7561605, DOI 10.1016/j.jep.2020.113478 (liver findings; PA-free variety in Austria); PMID 32413969, PMC 7290370, DOI 10.3390/toxins12050320 (German and EU PA exposure limits); PMID 7720737, DOI 10.1007/BF01991912 (1995 infant veno-occlusive disease case and the Adenostyles alliariae misidentification); PMID 32105669, DOI 10.1016/j.fitote.2020.104519 (systematic review and quality assessment of the case reports); this site’s existing toxicity note. Reference safety information, not a description of use.

• This herb is considered toxic.
  (while some Chinese herbs are toxic, it must be noted that many come prepared, or are combined, to mitigate their toxicity)

Herb-Drug Interactions

• No controlled clinical herb–drug interaction studies exist for Kuan Dong Hua. The theoretically relevant consideration is additive rather than pharmacokinetic: pyrrolizidine alkaloids are hepatotoxic, so co-exposure with other PA-containing botanicals (comfrey, borage, butterbur, ragwort-contaminated material, some herbal teas and honeys) or with hepatotoxic medication adds to a cumulative hepatic burden, and the regulatory limits described in the toxicity section are set on total daily PA exposure rather than per-product. (Precautionary reference context flagged for practitioner and physician confirmation, not a demonstrated clinical interaction list.)

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Kuan Dong Hua (Tussilago farfara)?

  Yes — a substantial preclinical literature centred on tussilagone, the herb’s principal sesquiterpenoid and its pharmacopoeial marker compound, alongside an extensive analytical literature on measuring its pyrrolizidine alkaloids. There are no controlled human efficacy trials to report. Two comprehensive reviews published in 2020 and 2021 cover the botany, traditional uses, phytochemistry, pharmacology, toxicology and quality control of the species.

  • Tussilagone, anti-inflammatory activity — a 2009 study reported that tussilagone’s anti-inflammatory effect in murine macrophages is mediated by induction of haem oxygenase-1, and a 2018 study found it reduced inflammatory responses in a dextran-sulphate-sodium murine colitis model. Cell and animal models.
  • Other sesquiterpenoids — a 2014 study isolated sesquiterpenoids from the plant and characterised their inhibition of nitric oxide production, consistent with the anti-inflammatory theme.
  • Bone metabolism (animal) — a 2020 study reported that tussilagone promoted osteoclast apoptosis and prevented oestrogen-deficiency-induced osteoporosis in mice. An off-target finding, and preclinical only.
  • Analytical and quality-control chemistry — a large body of work exists specifically on quantifying senkirkine and senecionine in this herb, using microwave-assisted and pressurised hot-water extraction with LC-MS/MS, field-amplified sample-stacking micellar electrokinetic chromatography, molecularly imprinted polymer solid-phase microextraction, and cation-exchange solid-phase extraction with ion-pair HPLC for free bases and N-oxides. NMR-based metabolomics has been applied to distinguish different Farfarae Flos samples. The volume of this literature is itself a signal of how much the alkaloid content matters commercially and regulatorily.
  • Toxicology — see the toxicity section for the rodent carcinogenicity and metabolite work, and for the systematic review of the human case reports.

  Overall: a real preclinical pharmacology around tussilagone, a mature analytical toxicology around the alkaloids, and no clinical efficacy evidence. Research context, not a therapeutic claim.

  Sources: PMID 33069788, PMC 7561605, DOI 10.1016/j.jep.2020.113478 (2021 review of Tussilago farfara); PMID 32526340, DOI 10.1016/j.jep.2020.113038 (2020 Farfarae Flos review); PMID 19800419, DOI 10.1016/j.intimp.2009.09.016 (tussilagone and haem oxygenase-1); PMID 30142311, DOI 10.1016/j.cbi.2018.08.022 (tussilagone in murine colitis); PMID 24963619, DOI 10.1055/s-0034-1368567 (sesquiterpenoids and nitric oxide inhibition); PMID 32807498, DOI 10.1016/j.bbrc.2020.07.083 (tussilagone and osteoclast apoptosis); PMID 19559918, DOI 10.1016/j.talanta.2009.04.028; PMID 27673325, DOI 10.1002/jssc.201600762; PMID 31453662, DOI 10.1002/jssc.201900665; PMID 11999741, DOI 10.1016/s0021-9673(01)01498-4; PMID 26234144 (NMR-based metabolomic comparison of Farfarae Flos). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Kuan Dong Hua different from Zi Wan and the other cough herbs?

  Kuan Dong Hua and Zi Wan are the classic pair among the cough-and-wheeze herbs, and they are close enough that the difference is one of emphasis rather than category. Both are Lung-channel herbs that moisten, stop cough and transform phlegm, and both are usable across cold, heat and deficiency patterns — unusual flexibility in a category where most herbs are pattern-specific.

  • Kuan Dong Hua — acrid and warm; our record places its emphasis on descending rebellious Lung qi and stopping the cough itself. It is the more warming of the pair.
  • Zi Wan — bitter, sweet and slightly warm; the emphasis falls more on expelling phlegm than on suppressing cough. Its warming quality is gentler.
  • Used together — the pair is given jointly precisely because the two emphases complement each other; separating them is more a teaching device than a clinical distinction.

  Formula context. In Ding Chuan Tang it sits with Zi Su Zi, Xing Ren and Sang Bai Pi in the phlegm-descending group of a formula built for mixed exterior wind-cold with interior phlegm-heat wheeze. In Jiu Xian San it appears in an astringent, Lung-consolidating formula for chronic depleted cough. Formula context, not treatment advice.

  Sources: identity records for Kuan Dong Hua and Zi Wan held on this site; formula composition records held on this site; materia medica consensus on the cough-and-wheeze category, cross-referenced against multiple online sources.

This herb is toxic or restricted in the United States