Cao Guo
StarLanxangia tsao-ko (Crevost & Lemarié) M.F.Newman & Škorničk.
Traditionally used for
- Cough & breathing
- Colds & fever
- Digestion
- Bowel health
☯ TCM Properties
Warms the Middle and Dries Dampness; Checks Malaria; Expels Phlegm; Disperses Cold; Promotes Digestion and Resolves Food Stagnation
Traditional Chinese Uses
Cao Guo (tsaoko fruit) is a warm, strongly aromatic herb that dries Dampness, warms the middle burner, and addresses malaria. It is used for cold-Damp obstruction of the Stomach with nausea, vomiting, and diarrhea, and historically for alternating fever-chill patterns of malarial origin. Its intense aromatic nature gives it a drying and dispersing action stronger than many other warming, Dampness-resolving herbs, and it is particularly appropriate for cold-type gastric and digestive conditions with significant Damp accumulation.
Western Herbalism Properties
Relationships
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Botanical Description
Lanxangia tsao-ko, formerly Amomum tsao-ko and known in Chinese medicine as Cao Guo, is a robust, tufted perennial rhizomatous herb in the Zingiberaceae, native to the warm-temperate mountain forests of southwestern China, northern Vietnam, Laos and Myanmar. The plant forms dense clumps 2 to 3 meters tall from a thick, branching, aromatic rhizome. The leaf-bearing pseudostems are erect and bear two ranks of large, oblong-lanceolate leaves 40 to 70 cm long and 10 to 20 cm wide, with parallel venation and a strongly aromatic sheath. Separate, short flowering shoots arise directly from the rhizome at ground level, bearing a dense spike of pale yellow or orange tubular flowers with red-streaked labella. The fruit is an ovoid to ellipsoid, three-locular capsule about 2 to 4.5 cm long, with a thick, longitudinally ridged red-brown to greyish pericarp enclosing many irregularly polygonal, intensely camphoraceous seeds embedded in pulp. The dried mature fruit is the medicinal drug.
Active Constituents
1,8-Cineole (eucalyptol)
Monoterpenoid oxideConcentration: 25.92% of the fruit essential oil in a study that identified 32 oil components
The single largest component of the fruit oil in most composition studies and the compound that gives the drug its camphoraceous smell. It carries much of the oil's antibacterial activity, which was strong enough in vitro (minimum inhibitory concentrations from about 22 to 1439 micrograms per millilitre against clinical isolates) that the whole oil protected mice in a Staphylococcus aureus and Escherichia coli peritonitis model.
Geraniol
Acyclic monoterpene alcoholConcentration: 13.69% of the fruit essential oil in the same 32-component analysis
The second most abundant oil component and a contributor to the broad-spectrum antibacterial activity of the oil. It is also a widely used flavour and fragrance material, which is why the fruit doubles as a culinary spice in the same regions where it is used medicinally.
Neral
Monoterpene aldehydeConcentration: Varies markedly with post-harvest drying method; identified as one of four differential odorant markers separating natural, open-fire, air-source and hot-air dried fruit
Part of the citral pair that dominates the fruit's lemony top note. Its abundance depends on how the fruit was dried, and drying method also changed the oil's in vitro alpha-amylase and alpha-glucosidase inhibition and its antioxidant capacity, so processing is not chemically neutral for this drug.
Germacrene D
Sesquiterpene hydrocarbonConcentration: One of four differential markers distinguishing drying methods; abundance highest in some drying regimes than others
A sesquiterpene of the fruit volatile fraction used, with 4-terpineol, neral and (Z)-2-decenol, as a marker of processing history. It has no separately established clinical activity in this drug.
Isotsaokoin
Bicyclic nonaneConcentration: Isolated as the major active principle of a methanol extract during bioassay-guided fractionation; not quantified as a routine marker
An isomer of tsaokoin and one of the structurally distinctive non-volatile constituents of this fruit. It was isolated by antifungal bioassay-guided purification and is active against Trichophyton mentagrophytes. The bicyclic nonanes are useful chemically because they are characteristic of this species rather than shared with the cardamom drugs it is confused with.
⚠ Drug Interactions
Amomum paratsaoko, Amomum koenigii or Alpinia katsumadai (Cao Dou Kou) substituted for Cao Guo
Three drugs are documented adulterants of Cao Guo: Amomum paratsaoko, Amomum koenigii and Alpinia katsumadai, confused because of overlapping records in the classical literature, adjacent growing areas and similar fruit morphology. In a functional dyspepsia rat model the four materials were not equivalent: they regulated different numbers of metabolic pathways (six for A. paratsaoko, five for genuine A. tsaoko, four for A. koenigii and only two for A. katsumadai), with corresponding differences in gastric emptying and intestinal propulsion (Li et al. 2024, animal). The Ben Cao Gang Mu itself grouped these plants into one category, which is the historical root of the modern substitution problem.
Clinical note: Order by binomial, not by pinyin, and require a certificate of analysis naming the species. Cao Guo is the whole dried ripe fruit; Cao Dou Kou is a seed, so the two are separable by inspection. Substitution is likely to weaken rather than to poison the prescription, but it does change what the patient receives.
Antimalarial drugs (artemisinin-based combination therapy, chloroquine)
Cao Guo's classical indication to check malaria comes from its role in Da Yuan Yin and other warm-disease formulas for intermittent fevers, a category that maps only loosely onto Plasmodium infection. Reviews of the fruit's pharmacology record antibacterial, anti-inflammatory and antioxidant activity but no demonstrated antiplasmodial action, and no clinical trial in malaria has been published. Absence of an assay is not evidence of activity.
Clinical note: Do not let this herb, or a formula containing it, displace or delay diagnostic testing and standard antimalarial treatment in a patient with suspected malaria. It may be used alongside conventional therapy for digestive symptoms.
Antidiabetic agents (metformin, acarbose, sulfonylureas, insulin)
Fruit essential oil inhibits alpha-amylase and alpha-glucosidase in vitro, with the degree of inhibition depending on how the fruit was dried (Xin et al. 2026, in vitro). The mechanism overlaps with acarbose. Note that the better-developed antidiabetic chemistry in this species, the diarylheptanoids and isospongian diterpenoids that inhibit alpha-glucosidase and DPP-4, was isolated from the leaves, which are not the drug; that evidence should not be read across to the fruit.
Clinical note: Culinary quantities are not a concern. If a diabetic patient takes concentrated fruit oil or extract alongside acarbose or a sulfonylurea, ask them to watch for post-prandial hypoglycaemia during the first weeks.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–6 g | Daily | — | — | 中国药典 2020 【用法与用量】3～6g。 【性味与归经】辛，温。归脾、胃经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
The warm drying action that disperses turbid dampness and interrupts malarial disorders is balanced by a cool herb that clears heat and protects yin.
Malarial disorders and membrane-source patterns with alternating chills and fever.
Named pairing — Lü Jingshan, Shi Jinmo Dui Yao
Evidence Tier
Moderate evidence · 5 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
5
3 verified · 2 unverified
Show 5 studies
- Comparison of the effects of Amomum tsaoko and its adulterants on functional dyspepsia rats based on metabolomics analysis
- Anti-infectious efficacy of essential oil from Caoguo (Fructus Tsaoko)
- Investigation on the effects of drying methods on Amomum tsaoko in key odorants, in vitro antidiabetic, anticancer, and antioxidant activities
- Isotsaokoin, an Antifungal Agent from Amomum tsao-ko
- The Amomum tsao-ko Essential Oils Inhibited Inflammation and Apoptosis through p38/JNK MAPK Signaling Pathway and Alleviated Gentamicin-Induced Acute Kidney Injury
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
Comparison of the effects of Amomum tsaoko and its adulterants on functional dyspepsia rats based on metabolomics analysis
Genuine Amomum tsaoko was compared head to head with its three named adulterants, Amomum paratsaoko, Amomum koenigii and Alpinia katsumadai, in a rat model of functional dyspepsia, measuring gastric emptying, intestinal propulsion, serum biochemistry, histology and faecal metabolomics. Twenty biomarkers across seven metabolic pathways separated the treatments, and the four materials regulated different numbers of pathways, confirming that the adulterants are not therapeutically interchangeable with the genuine drug.
Anti-infectious efficacy of essential oil from Caoguo (Fructus Tsaoko)
Fruit essential oil inhibited clinical bacterial isolates by agar dilution with minimum inhibitory concentrations from about 22 to 1439 micrograms per millilitre, and protected mice in a Staphylococcus aureus or Escherichia coli peritonitis model. Thirty-two oil components were identified, with 1,8-cineole at 25.92% and geraniol at 13.69% as the major ones. This is a microbiological and rodent study; the oil has not been tested as an anti-infective in humans.
Investigation on the effects of drying methods on Amomum tsaoko in key odorants, in vitro antidiabetic, anticancer, and antioxidant activities
Natural, open-fire, air-source and hot-air drying produced measurably different fruit oils, with (Z)-2-decenol, germacrene D, 4-terpineol and neral as differential markers. Hot-air and air-source dried oils inhibited alpha-amylase and alpha-glucosidase most strongly, air-source oil was most cytotoxic to A549 cells, and naturally dried oil had the strongest radical scavenging. The practical point for a dispensary is that post-harvest processing, not just species, determines this drug's chemistry.
Isotsaokoin, an Antifungal Agent from Amomum tsao-ko
Bioassay-guided purification of a methanol extract of the fruit yielded the bicyclic nonane isotsaokoin as the major active principle, an isomer of the previously described tsaokoin, with activity against the dermatophyte Trichophyton mentagrophytes. An isolated-compound antifungal screen, not a clinical finding.
The Amomum tsao-ko Essential Oils Inhibited Inflammation and Apoptosis through p38/JNK MAPK Signaling Pathway and Alleviated Gentamicin-Induced Acute Kidney Injury
Fruit essential oil reduced inflammation and apoptosis via p38/JNK MAPK signalling and lessened gentamicin-induced acute kidney injury in rodents. It is a preclinical nephroprotection model and does not establish a renal indication for the drug in people.
Historical Texts
Tai Ping Hui Min He Ji Ju Fang (Formulary of the Bureau of People's Welfare Pharmacies)
Northern Song dynasty, compiled from the late 11th centuryYin Shan Zheng Yao (Principles of Correct Diet), Hu Sihui
Yuan dynasty, 1330Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596Wen Yi Lun (Treatise on Warm Epidemics), Wu Youxing, Da Yuan Yin formula
Late Ming, 1642Pharmacopoeia of the People's Republic of China, Tsaoko Fructus (Cao Guo) monograph
Modern standard, 2020 editionReferences
- Yang S; Xue Y; Chen D; Wang Z. Amomum tsao-ko Crevost & Lemarié: a comprehensive review on traditional uses, botany, phytochemistry, and pharmacology . Phytochemistry Reviews (2022) [DOI]
- He G; Yang SB; Wang YZ. The potential of Amomum tsao-ko as a traditional Chinese medicine: Traditional clinical applications, phytochemistry and pharmacological properties . Arabian Journal of Chemistry (2023) [DOI]
- Pu Y; Wu J; Liu C; Xu Z; Liu K; Zhang H; Yang Y; Xia C. Unveiling the Value of Amomum tsaoko Crevost & Lem.: A Review from Bioactive Compounds to Health Benefits and Industrial Applications . Foods (2026) [DOI]
- Liao L; Yang S; Li R; Zhou W; Xiao Y; Yuan Y; Cha Y; He G; Li J. Anti-inflammatory effect of essential oil from Amomum Tsaoko Crevost et Lemarie . Journal of Functional Foods (2022) [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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