Ba Dou
StarCroton tiglium L.
Traditionally used for
- Nose & throat
- Cough & breathing
- Bowel health
- Urinary & fluids
Cautions & contraindications
- Pregnancy
- Heart conditions
- Toxic — professional use only
☯ TCM Properties
Purges Cold Accumulation; Drains Water and Reduces Edema; Clears the Lungs and Benefits the Throat; Removes Putridity and Promotes Tissue Regeneration
Traditional Chinese Uses
Ba Dou (croton seed) is one of the most forceful purgative herbs in Chinese medicine, capable of expelling severe internal cold-type accumulation from the intestines and draining pathological fluid from the chest and abdomen. It is reserved for emergency conditions involving critical obstruction or stubborn fluid accumulation where gentler treatments have failed. Because it is highly toxic, its oil must be removed before use, and it requires strictly professional administration.
Relationships
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Botanical Description
Croton tiglium is a small evergreen tree or shrub in the Euphorbiaceae family, native to southern and southeastern Asia, including India, Sri Lanka, southern China, and Indonesia. It typically grows 3-6 meters tall with smooth, pale grey-brown bark and a spreading crown. The alternate leaves are ovate to lanceolate, 5-15 cm long, with serrate margins, three to five conspicuous palmate veins from the base, and two small glands at the petiole junction; young leaves are often coppery-red. The plant is monoecious, with small greenish-yellow flowers in terminal racemes; male flowers are above and female flowers below. The fruit is a three-lobed capsule, 2 cm across, containing three oblong-ovoid brown seeds. The seeds (Ba Dou) contain the highly toxic, vesicant croton oil with phorbol esters, and are used in TCM only after extensive processing as a drastic purgative for cold accumulation.
Active Constituents
Croton oil (fixed seed oil)
Fixed oil, a mixture of glycerides with tigliane diterpene estersConcentration: reported at roughly 34-57% of the seed; the Chinese Pharmacopoeia processed drug Ba Dou Shuang is the defatted powder, specified at a much reduced residual fixed-oil content of about 18-20%
Croton oil is the vehicle for the drastic purgative and vesicant action of this drug. It is a violent gastrointestinal irritant: reported lethal quantities in the older toxicology literature are of the order of 4-5 crushed seeds or about 20 drops (1-2 mL) of the oil, with death occurring between six hours and three days. Deaths from croton oil are documented, and the clinical picture of severe poisoning has been likened to cholera. On skin it produces immediate erythema and blistering. It is precisely because of this oil that internal use is confined to the defatted preparation.
12-O-tetradecanoylphorbol-13-acetate (TPA, also called phorbol 12-myristate 13-acetate or PMA)
Tigliane diterpene ester (phorbol ester)Concentration: a trace constituent of the oil; active in nanomolar amounts, so trace quantities are pharmacologically decisive
TPA is the single most consequential compound in this drug. It is a direct activator of protein kinase C, which is why it is intensely irritant and inflammatory at vanishingly low concentrations. It is also the reference tumour promoter of the mouse two-stage skin carcinogenesis model, the assay in which the entire concept of tumour promotion was defined: applied repeatedly after an initiating carcinogen, it drives papilloma and carcinoma formation. Croton oil should be handled as a laboratory tumour promoter, not merely as an irritant.
12-O-hexadecanoylphorbol-13-acetate and related phorbol esters
Tigliane diterpene esterCroton oil contains a family of phorbol esters beyond TPA, of which around 150 compounds in total have been described from the plant. They share the irritant and PKC-activating profile, and several are cytotoxic in cancer cell lines. They are the components that processing aims to reduce.
Crotonic acid
Unsaturated short-chain carboxylic acidAn irritant constituent of the seed that is measurably reduced by traditional detoxification processing; in the Thai detoxification study it fell from a detectable level in untreated seed to undetectable after treatment.
Crotin
Toxalbumin (ribosome-inactivating lectin)A protein toxin of the seed that inhibits protein synthesis, causes haemolysis and produces local cell necrosis. Because it is a protein it does not partition into the expressed oil, so it remains in the seed cake and in Ba Dou Shuang; it is a distinct toxicological hazard from the phorbol esters and is not removed by defatting.
Crotonoside (isoguanosine)
Purine nucleosideA characteristic non-diterpene constituent of Croton tiglium seed, used chemically as a marker for the drug. It does not contribute to the purgative or irritant action.
⚠ Drug Interactions
Qian Niu Zi (Pharbitis / Ipomoea nil seed)
Ba Dou and Qian Niu Zi form one of the pairs of the classical Nineteen Mutual Fears (Shi Jiu Wei), where the tradition records that the two must not be combined. Pharmacologically the pairing is two drastic purgatives with different mechanisms given together, so the traditional prohibition and the modern reasoning point the same way: additive violent catharsis with dehydration, hypokalaemia and circulatory collapse. A small number of historical formulas do combine them, but the prohibition is the default position and is taught as such.
Clinical note: Do not prescribe the two together. If a classical formula appears to combine them, treat that as requiring specialist justification and not as licence to ignore the rule.
Digoxin and other cardiac glycosides
The purgative action of croton oil produces profuse watery, sometimes bloody, diarrhoea. Faecal potassium loss and the secondary renal response to sodium loss lower serum potassium, and hypokalaemia increases the binding of cardiac glycosides to the Na+/K+ ATPase, potentiating their inhibitory effect. The same mechanism is documented for the milder anthranoid laxatives; croton is a far more violent cathartic, so the risk is correspondingly greater.
Clinical note: Do not use this herb in any patient on digoxin or another cardiac glycoside. If it has been taken, check serum potassium and consider a digoxin level.
Loop and thiazide diuretics, corticosteroids and liquorice (Gan Cao)
All of these lower serum potassium by their own mechanisms. Added to the profuse diarrhoea caused by croton, the result is compounded hypokalaemia and hypovolaemia, with the arrhythmia and muscle-weakness consequences that follow.
Clinical note: Avoid the combination. Where a patient on any of these has been exposed to croton, treat as a fluid and electrolyte emergency rather than as simple diarrhoea.
All orally administered medicines
Violent catharsis and vomiting sharply reduce gastrointestinal transit time and mucosal contact, so the absorption of any co-administered oral drug is unreliable. Anticonvulsants, immunosuppressants, oral anticoagulants and oral contraceptives are the exposures where the loss of a dose matters most.
Clinical note: Assume that oral medication taken during croton-induced purgation has not been absorbed, and manage critical drugs accordingly.
Other stimulant and irritant purgatives (senna, bisacodyl, Qian Niu Zi, Gan Sui, Da Ji)
Croton is the most drastic purgative in the materia medica. Any further cathartic added to it produces catharsis that cannot be titrated, with the same dehydration and electrolyte consequences described above.
Clinical note: Never stack purgatives with Ba Dou. Classically its purgation is checked with cold rather than hot fluids, and hot drinks are said to intensify it.
Topical corticosteroids and other skin therapy at the same site
Croton oil on the skin causes erythema and vesication through phorbol ester activation of protein kinase C, with leukocyte infiltration and histamine release. Repeated topical exposure is the standard experimental tumour-promoting stimulus in mouse skin. There is therefore no safe schedule of repeated topical croton oil application, whatever else is being applied to the same area.
Clinical note: Do not use croton oil topically for repeated or cosmetic purposes. If it is used at all it is a single-use escharotic under supervision, and the operator should avoid skin and eye contact.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| topical | Appropriate amount | — | — | — | ChP 2025. 巴豆 is given EXTERNALLY ONLY — 研末涂患处，或捣烂以纱布包擦患处 (powdered and applied, or crushed and rubbed on through gauze). The Pharmacopoeia gives no internal dose for the crude drug; the internal form is the defatted 巴豆霜 (Ba Dou Shuang) at 0.1–0.3 g in pills or powder. Contraindicated in pregnancy; not combined with Qian Niu Zi. Corrected from a generic 6-15g decoction filler value generated from tcm_category. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Hot drastic purging combined with warming of the middle, which expels cold accumulation from the stomach and intestines.
Acute cold accumulation with sudden abdominal distention and pain and constipation. Ba Dou is highly toxic; contraindicated in pregnancy and weak patients; incompatible with Qian Niu Zi (nineteen antagonisms).
Core pair of a classical formula — San Wu Bei Ji Wan, Jin Gui Yao Lue (Zhang Zhongjing)
Evidence Tier
Moderate evidence · 4 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
4
2 verified · 2 unverified
Show 4 studies
- Purgative Effect, Acute Toxicity, and Quantification of Phorbol-12-Myristate-13-Acetate and Crotonic Acid in Croton tiglium L. Seeds Before and After Treatment by Thai Traditional Detoxification Process
- Assessment of acute, 14-day, and 13-week repeated oral dose toxicity of Tiglium seed extract in rats
- Cytotoxic Phorbol Esters of Croton tiglium
- Detoxification of Croton tiglium L. seeds by Ayurvedic process of Śodhana
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Purgative Effect, Acute Toxicity, and Quantification of Phorbol-12-Myristate-13-Acetate and Crotonic Acid in Croton tiglium L. Seeds Before and After Treatment by Thai Traditional Detoxification Process
Compared untreated and traditionally detoxified Croton tiglium seed in rats. Only the untreated seed at 100 mg/kg produced significant purgation; the detoxification process reduced crotonic acid to undetectable levels and lowered the phorbol-12-myristate-13-acetate content, though not to zero. Acute LD50 of the seed extract in rats was above 2000 mg/kg for both preparations. The study is direct evidence that processing changes both the irritant chemistry and the purgative effect, which is why raw and processed croton must not be treated as the same drug.
Assessment of acute, 14-day, and 13-week repeated oral dose toxicity of Tiglium seed extract in rats
A regulatory-style acute, 14-day and 13-week repeated-dose oral toxicity study of Croton tiglium seed extract in rats, establishing dose-related toxicity and a no-observed-adverse-effect level for the extract tested. The value of the study for practice is that it documents systemic toxicity on repeated dosing, not only the acute purgative event.
Cytotoxic Phorbol Esters of Croton tiglium
Isolated and characterised phorbol esters from Croton tiglium and measured their cytotoxicity in cancer cell lines. Confirms that the tigliane diterpene fraction, and not the bulk glyceride oil, carries the cytotoxic as well as the irritant activity of the drug.
Detoxification of Croton tiglium L. seeds by Ayurvedic process of Śodhana
Quantified the phorbol ester and crotonic acid content of Croton tiglium seed before and after the Ayurvedic Sodhana purification process, showing measurable reduction of the irritant constituents. A parallel to the Chinese practice of defatting to Ba Dou Shuang, and evidence that traditional processing is a genuine chemical intervention rather than a ritual step.
⚠ Safety & Contraindications
- Pregnancy
- Heart conditions
- Toxic — professional use only
Contraindications
Contraindicated in pregnancy, in the weak or depleted, and in any patient who is not robust. Not for use where heat signs predominate.
Safety Warnings
- Only the processed, de-oiled preparation (Ba Dou Shuang) is used internally; the raw seed is not given by mouth.
- Incompatible with Qian Niu Zi (Semen Pharbitidis) under the classical nineteen antagonisms.
- Handle with gloves — the oil blisters skin on contact.
⚠ Rule-Based Cautions
These entries come from the deterministic rule tables that gate Verscienta's formula tools — classical pair prohibitions, pregnancy and lactation contraindications, and dose ceilings.
Incompatibilities (十八反 / 十九畏)
- 十九畏: Ba Dou × Qian Niu — avoid combining with Qian Niu / Pharbitis / Morning glory
Pregnancy
Avoid toxic drastic purgative
⚠ Toxicity Information
Severe vomiting and watery diarrhoea, burning of the mouth and throat, abdominal colic, dehydration and collapse. Direct contact blisters skin and mucous membrane; the oil is a documented tumour promoter.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyShang Han Lun
Han dynastyBen Cao Gang Mu
Ming dynasty (1596)References
- Zhang T, Liu Z, Sun X, Liu Z, Zhang L, Zhang Q, Peng W, Wu C. Botany, traditional uses, phytochemistry, pharmacological and toxicological effects of Croton tiglium Linn.: a comprehensive review . Journal of Pharmacy and Pharmacology (2022) [DOI]
- Hecker E. Phorbol esters from croton oil chemical nature and biological activities . Naturwissenschaften (The Science of Nature) (1967) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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