Chang Shan
StarDichroa febrifuga Lour.
Traditionally used for
- Nose & throat
- Cough & breathing
- Colds & fever
- Digestion
Cautions & contraindications
- Pregnancy
- Young children
- Liver conditions
- Kidney conditions
- Toxic — professional use only
☯ TCM Properties
Checks Malaria; Induces Vomiting to Expel Phlegm; Clears Heat
Traditional Chinese Uses
Chang Shan (常山) is the root of Dichroa febrifuga Lour. (Hydrangeaceae), Radix Dichroae. It is bitter and acrid and cold and toxic, entering the Lung, Liver and Heart channels. It checks malarial disorders, induces vomiting to expel Phlegm, and clears Heat.
It is the classical Chinese antimalarial, given shortly before an expected paroxysm of fever and chills, and it remains the reference drug for that indication in the tradition; its alkaloids, the febrifugines, are genuinely and potently antiplasmodial. Its second use is deliberate emesis, to dislodge thick Phlegm congesting the chest and throat in conditions where Phlegm obstructs the orifices.
Nausea and vomiting are its expected effect rather than an adverse one, which sharply limits its tolerability; frying it in wine or combining it with ginger moderates this. It is toxic, and is contraindicated in pregnancy and in patients weakened by chronic illness or with a depleted constitution. Dosing is conservative and courses are short.
Western Herbalism Properties
Relationships
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Botanical Description
Dichroa febrifuga (blue evergreen hydrangea, Chinese quinine) is an evergreen shrub in the Hydrangeaceae family, growing 1-2 m tall in warm-temperate to subtropical forests of southern China, the Himalayas, and Southeast Asia. The opposite, elliptic-lanceolate to oblong, finely serrate leaves are 12-25 cm long, dark green and glabrous above, paler beneath, with a long acuminate tip. Small star-shaped flowers, white to blue or violet-blue depending on soil chemistry, are borne in flat-topped terminal or axillary corymbose cymes; each flower has 4-6 spreading petals and prominent stamens. The fruit is a bright metallic blue, fleshy, globose berry about 5 mm across containing many small seeds. The roots are stout, branching, yellowish-brown, and bitter (POWO; Wikipedia).
Active Constituents
Febrifugine
Quinazolinone alkaloid (3-piperidyl-4-quinazolinone)The principal active alkaloid of the root and the reason this herb matters pharmacologically. It is a potent antimalarial against Plasmodium falciparum, and it is also active against Leishmania, Schistosoma, Eimeria and Phytophthora at nanomolar to low-micromolar concentrations. Its molecular target, established through the semisynthetic derivative halofuginone, is prolyl-tRNA synthetase; inhibition of that enzyme triggers the amino acid starvation response. Febrifugine is simultaneously the toxic principle: it is strongly emetic and hepatotoxic, which is precisely why it was never developed as an antimalarial drug despite good antiparasitic activity at around 2.5 mg/day orally.
Isofebrifugine
Quinazolinone alkaloidThe stereoisomeric partner of febrifugine, which interconverts with it and co-occurs in the root. The two are quantified together as the marker pair in HPLC assays of Chang Shan root. Isofebrifugine is generally reported as the less active of the pair.
Dichroine alkaloid fraction (dichroines alpha, beta and gamma)
Quinazolinone alkaloid fractionThe historical Chinese names for the antimalarial alkaloids of Chang Shan root, corresponding to febrifugine and isofebrifugine and their interconversion products. The total alkaloid fraction, often prepared as the alkaline salt, carries both the antimalarial and the emetic activity, and it is the fraction used in the rat pica studies that mapped the emetic mechanism.
4-Quinazolinone
QuinazolinoneA simple quinazolinone reported among the roughly thirty compounds isolated from the plant. It is a structural fragment of the febrifugine scaffold and is not credited with the antimalarial activity.
⚠ Drug Interactions
Emetogenic chemotherapy and other nausea-inducing drugs (e.g. cisplatin, opioids, SSRIs)
Emesis is not an occasional side effect of this herb, it is its defining pharmacology - Chang Shan was classically used deliberately as an emetic to expel phlegm. Work in rats showed that Dichroa alkali salt induces acute pica through activation of 5-hydroxytryptamine and substance P pathways, the same 5-HT3 and NK1 mechanisms exploited by cisplatin. Layering it onto another agent acting through those pathways is directly additive.
Clinical note: Do not combine Chang Shan with emetogenic chemotherapy or with any drug in a patient who cannot tolerate vomiting. Traditional processing - soaking in wine, dry-frying - is used to blunt the emetic action, but it does not abolish it.
5-HT3 receptor antagonists (e.g. ondansetron) and NK1 antagonists (e.g. aprepitant)
In the rat pica model, receptor antagonists targeting the serotonin and substance P pathways blocked the emetic response to Dichroa alkali salt. That is useful mechanistic confirmation, but it creates a practical hazard: emesis is the body's own limit on how much febrifugine gets absorbed and retained. Blocking it allows continued dosing of an alkaloid that damages liver, kidney and heart.
Clinical note: Never give an antiemetic to allow a patient to tolerate a larger or longer course of Chang Shan. If vomiting occurs, that is the signal to stop the herb, not to suppress the symptom.
Hepatotoxic and nephrotoxic drugs (e.g. paracetamol/acetaminophen, methotrexate, isoniazid, aminoglycosides, NSAIDs)
The alkaloids that give this herb its efficacy also cause multiple organ damage, including liver, kidney and heart, alongside gastrointestinal adverse effects. Strong liver toxicity is the specific reason febrifugine was abandoned as a clinical antimalarial candidate. Adding a second organ-toxic drug compounds a risk that is intrinsic to the herb rather than incidental.
Clinical note: Chang Shan should not be used in patients with liver or kidney impairment, in the elderly or debilitated, or in children without close supervision. It is contraindicated in pregnancy - the alkaloids stimulate uterine contraction. Keep courses short and doses within the 5-9 g Pharmacopoeia range; this is not a herb for long-term use.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 5–9 g | — | — | — | ChP 2025. 有催吐副作用，用量不宜过大 — emesis is an expected side effect and the dose should not be exceeded; caution in pregnancy. Frying in wine or pairing with ginger moderates the nausea. Corrected from a generic 6-15g 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.
Expelling phlegm and checking malaria combined with moving qi downward, which also lessens the nausea and vomiting caused by Chang Shan.
Malaria patterns with phlegm. Chang Shan is toxic and emetic; use processed and with caution; contraindicated in pregnancy and weakness.
Core pair of a classical formula — Jie Nue Qi Bao Yin, Yang Shi Jia Cang Fang (Yang Tan)
Evidence Tier
Moderate evidence · 6 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
1
1 verified · 0 unverified
Other clinical trial
1
1 verified · 0 unverified
Observational / case report
0
In vitro / animal
4
1 verified · 3 unverified
Show 4 studies
- Involvement of 5-Serotonin and Substance p Pathways in Dichroa Alkali Salt-Induced Acute Pica in Rats
- Antimalarial Activities and Therapeutic Properties of Febrifugine Analogs
- Halofuginone Inhibits TH17 Cell Differentiation by Activating the Amino Acid Starvation Response
- Halofuginone and other febrifugine derivatives inhibit prolyl-tRNA synthetase
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
Involvement of 5-Serotonin and Substance p Pathways in Dichroa Alkali Salt-Induced Acute Pica in Rats
Used kaolin pica in rats as a surrogate for emesis and showed that the Dichroa alkali salt fraction induces it through serotonin and substance P signalling, with receptor antagonists blocking the response. This is the clearest mechanistic account of why Chang Shan makes people vomit and why the herb failed as a drug candidate.
Antimalarial Activities and Therapeutic Properties of Febrifugine Analogs
Evaluated febrifugine and synthetic analogues against Plasmodium in rodent and primate models. Confirmed strong antimalarial potency for the febrifugine scaffold while documenting the toxicity that has kept the parent alkaloid out of clinical use, and set out the medicinal-chemistry case for analogues with a better therapeutic index.
Halofuginone Inhibits TH17 Cell Differentiation by Activating the Amino Acid Starvation Response
Halofuginone, the semisynthetic derivative of Chang Shan's febrifugine, selectively blocked differentiation of pro-inflammatory TH17 cells without affecting other T helper lineages, and protected mice from TH17-driven autoimmune inflammation. The mechanism was traced to activation of the amino acid starvation response, and the effect was reversed by excess amino acids - the observation that led directly to the identification of prolyl-tRNA synthetase as the target. This established the febrifugine scaffold as an immunological tool compound; it concerns the derivative, not the crude herb.
Halofuginone and other febrifugine derivatives inhibit prolyl-tRNA synthetase
Identified prolyl-tRNA synthetase as the molecular target of halofuginone and of febrifugine itself, showing that the compounds occupy the proline and tRNA binding sites and that excess proline reverses their effect. This is the paper that turned Chang Shan's alkaloid from a folk antimalarial into a defined molecular probe.
Phase I and pharmacokinetic study of halofuginone, an oral quinazolinone derivative in patients with advanced solid tumours
Dose-escalation study in 24 patients of halofuginone, the semisynthetic derivative of Chang Shan's febrifugine. The recommended phase II dose was 0.5 mg once daily, and nausea and vomiting were the dose-limiting toxicities - the same emetic ceiling that defeated the parent alkaloid, reappearing in a compound specifically engineered to be less toxic. This trial studied the derivative drug, not the crude herb.
Halofuginone for non-hospitalized adult patients with COVID-19 a multicenter, randomized placebo-controlled phase 2 trial. The HALOS trial
Randomised, placebo-controlled phase 2 trial of halofuginone, the febrifugine derivative, in non-hospitalised adults with COVID-19. Treatment was safe and well tolerated but did not accelerate SARS-CoV-2 viral load decay. Included here as the most recent controlled human data on this chemical series; it says nothing about the efficacy of the crude herb.
⚠ Safety & Contraindications
- Pregnancy
- Young children
- Liver conditions
- Kidney conditions
- Toxic — professional use only
Contraindications
Contraindicated in pregnancy and in the weak or depleted.
Safety Warnings
- Emesis is the dose-limiting effect and occurs at close to therapeutic doses.
- Not for prolonged use.
⚠ 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.
Pregnancy
Avoid toxic emetic
⚠ Toxicity Information
Severe nausea and vomiting — so reliably that the drug was historically used as an emetic — with abdominal pain, and hepatic injury on prolonged use.
Historical Texts
Shen Nong Ben Cao Jing
Han dynasty (c. 1st-2nd century CE)Pharmacopoeia of the People's Republic of China
Modern (current edition)References
- Wang M, Xu XR, Bai QX, Wu LH, Yang XP, Yang DQ, Kuang HX. Dichroa febrifuga Lour.: A review of its botany, traditional use, phytochemistry, pharmacological activities, toxicology, and progress in reducing toxicity . Journal of Ethnopharmacology (2024) [DOI]
- Sheng LQ, Ma JL. Preparative separation of two isomeric antimalaria alkaloids febrifugine and isofebrifugine from Dichroa febrifuga roots by countercurrent chromatography . Journal of Separation Science (2021) [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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