Cao Guo (Tsaoko Fruit)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Cao Guo?

  Roughly 3–6 g in decoction — a deliberately modest range, because Cao Guo is pungent, hot-natured and easily drying. Its action depends on its volatile oil, so like other aromatic damp-transforming herbs it is added late in the decoction rather than boiled from the start. The seed cluster is customarily crushed before use; the papery outer shell is often discarded. In the classical formulas held here it is dosed lower still: 1.5 g in Da Yuan Yin and 6 g in Shi Pi Yin.

  Source: Sacred Lotus sources & references (dosage and formula composition amounts as recorded on file); preparation conventions per materia medica consensus. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Cao Guo?

  Do not use in qi deficiency or blood deficiency — that is the caution recorded on this site, and it follows directly from the herb’s character: Cao Guo is among the most pungent, hot and drying of the aromatic damp-transformers, and it disperses at the expense of the body’s reserves. The same logic extends to yin deficiency and to any pattern with heat or dryness.

  • Qi deficiency or blood deficiency — contraindicated as recorded; the dispersing, drying action depletes rather than supports.
  • Yin deficiency with heat, or fluid depletion — not indicated, consistent with the category caution for warm, drying aromatics.
  • No damp present — Cao Guo is aimed squarely at cold-damp accumulation; it is not a general digestive.
  • Dose discipline — the usual range is small (3–6 g) and the formulas use less still; exceeding it is not the way this herb is used.
  • Pregnancy — no specific traditional prohibition is recorded, but strongly dispersing warm aromatics are used only under professional supervision in pregnancy.
  • Identity — confirm the material is genuine Cao Guo and not one of its documented look-alike substitutes (see notes).

  Source: Sacred Lotus sources & references (recorded caution); category cautions per materia medica consensus, cross-referenced against multiple online sources. Reference note, not a safety guarantee.

Chinese Herb Toxicity & Overdose

• Low. Cao Guo is a “medicine and food homology” material — a standard culinary spice in Yunnan and Sichuan cooking, used in braises, hotpot bases and spice blends — and no significant toxicity is reported at normal medicinal doses. The practical limits on it are traditional rather than toxicological: it is hot and drying, so the caution is about pattern suitability and dose restraint rather than about a toxic constituent. Essential-oil work reports cytotoxicity only in concentrated in-vitro assays, which is expected of concentrated volatile oils generally and does not describe the decocted herb.

  Source: materia medica consensus; food-use status and essential-oil assay context from PMID 35626972, PMC 9141665 and PMID 41135723. Reference note, not a safety guarantee.

Herb-Drug Interactions

• No clinical herb–drug interactions are documented for Cao Guo. No human interaction study exists, and no CYP-inhibition or transporter data specific to this herb was located. Two areas would reasonably prompt practitioner awareness rather than a claimed interaction: preclinical work reports glucose-lowering effects in diabetic rodent models and α-glucosidase inhibition by its flavonoid fraction, so patients on antidiabetic medication warrant ordinary monitoring; and, as with any concentrated essential oil, the isolated oil should not be treated as equivalent to the decocted herb. Both points are precautionary. (Flagged for practitioner confirmation.)

  Source: preclinical glycaemic findings per PMID 40296313 and PMID 39897968, PMC 11786917. Reference context only — not medical advice.

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 Cao Guo (Amomum tsao-ko / Lanxangia tsaoko)?

  Yes — an active preclinical and food-science literature, weighted toward essential-oil chemistry, metabolic effects and quality control. There are no human clinical trials of the herb. Chemically Cao Guo is dominated by its volatile oil: analyses across growing regions identified 141 compounds, mainly terpenes and aldehydes, with 1,8-cineole, (E)-dec-2-enal, citral, α-pinene and α-terpineol standing out; the fruit also carries flavonoids, diarylheptanoids and polysaccharides.

  • Essential oil, antibacterial and antioxidant (in vitro) — the oil showed strong activity against Staphylococcus aureus and broad-spectrum antimicrobial and antioxidant activity in laboratory assays, with the constituents above identified as the likely actives. Laboratory work; not clinical.
  • Digestive function and adulterant comparison (animal) — in functional dyspepsia rats, Cao Guo and its three commercial adulterants regulated different sets of metabolic pathways, supporting both the traditional digestive indication and the argument that the substitutes are not equivalent.
  • Metabolic and glycaemic (animal, cell) — extracts reduced hyperglycaemia and cognitive deficits in type-2 diabetic mice via gut microbiota, short-chain fatty acids and CREB/BDNF/TrkB signalling; a flavonoid fraction inhibited α-glucosidase in vitro; diarylheptanoids from the leaves showed antidiabetic activity; and an extract reduced cholesterol and aortic lesions in atherosclerotic mice through the gut–liver axis.
  • Polysaccharides (animal) — a soluble polysaccharide attenuated colitis in mice via restoration of the intestinal barrier; other polysaccharide fractions show immunomodulatory activity.
  • Quality control and authentication — a chromosome-level genome, near-infrared and chemometric origin-authentication methods, and volatile profiling across fruit shapes and drying conditions have all been published, reflecting sustained concern with identifying genuine material and with how post-harvest handling changes the aroma.

  All of this is laboratory or animal evidence. None of it demonstrates clinical efficacy in people, and none of it is a treatment claim.

  Sources: PMID 35626972, PMC 9141665, DOI 10.3390/foods11101402 (essential oil composition and antibacterial activity); PMID 28800540, DOI 10.1016/j.jchromb.2017.08.001 (oil extraction, antioxidant and antimicrobial); PMID 38735210, DOI 10.1016/j.jpba.2024.116208 (adulterant comparison in functional dyspepsia rats); PMID 40296313, DOI 10.1111/nmo.70065 (T2DM mice); PMID 39897968, PMC 11786917 (flavonoids, α-glucosidase inhibition); PMID 40280249, DOI 10.1016/j.fitote.2025.106566 (antidiabetic diarylheptanoids); PMID 41244676, PMC 12617299 (atherosclerosis, gut–liver axis); PMID 42309454, DOI 10.1016/j.ijbiomac.2026.153070 (polysaccharide, colitis model); PMID 41054604, PMC 12496527 (genome and quality traits); PMID 41658529, PMC 12872912 (geographic authentication). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Cao Guo different from Cao Dou Kou, Bai Dou Kou and Rou Dou Kou?

  Four similarly-named warming aromatics, four different plants — and only one of them, Cao Guo, carries the malarial-disorder indication. The English names make this worse rather than better, since three of the four get called some kind of “cardamom” or “nutmeg” in translation. Sorting them by botanical source and by the one action each is actually reached for:

  • Cao Guo (草果, tsaoko fruit, Fructus Amomi Tsao-ko) — spicy, warm; Spleen, Stomach. The whole dried fruit of a large Zingiberaceae plant grown mainly in Yunnan. The strongest and most penetrating of the four for cold-damp in the middle burner, and the only one used for malarial disorders. Its Chinese name means “grass fruit.”
  • Cao Dou Kou (草豆蔻, Katsumada’s galangal seed, Semen Alpiniae Katsumadai) — spicy, warm, aromatic; Spleen, Stomach. The seed, and from a different genus (Alpinia, not Amomum). Warms and dries damp-cold in the middle burner, with no malarial indication and less penetrating reach.
  • Bai Dou Kou (白豆蔻, round cardamom fruit, Fructus Amomi Kravanh) — spicy, aromatic, slightly warm; Lung, Spleen, Stomach. Note the extra channel: Bai Dou Kou is the one that works on the upper as well as the middle burner, aromatically transforming damp for a stifling chest, and it is the group’s best choice for vomiting from cold. Despite the English “cardamom,” it is not true cardamom (Elettaria cardamomum).
  • Rou Dou Kou (肉豆蔻, nutmeg, Semen Myristicae Fragrantis) — spicy, warm; Large Intestine, Spleen, Stomach. Not a ginger-family plant at all — it is the nutmeg seed, Myristica fragrans. Its defining action is astringing the intestines for chronic diarrhoea, which none of the other three do.

  A quick way to hold it: if the target is chronic diarrhoea needing binding, that is Rou Dou Kou. If the chest is involved or the problem is vomiting, that is Bai Dou Kou. If it is heavy cold-damp in the middle burner with alternating chills and fever, that is Cao Guo. Cao Dou Kou is the plainer middle-burner damp-drier that sits between them.

  This confusion is documented in the supply chain, not just in translation. A comparative study of Cao Guo against its three recognized commercial adulterants — Amomum paratsaoko, Amomum koenigii and Alpinia katsumadai (the source plant of Cao Dou Kou) — noted the substitutions arise from confused source records in the historical classics plus overlapping geography and near-identical fruit morphology. Tested side by side in a functional dyspepsia rat model, the four materials regulated different numbers of metabolic pathways, indicating they are not equivalent substitutes.

  Discrepancy flagged for review: the comparison recorded on this site states that Cao Dou Kou and Cao Guo both warm the middle and dry damp, with Cao Dou Kou the slightly stronger of the two. Other materia medica sources rank it the other way round — treating Cao Guo as the more strongly drying and dispersing, and pointing to its malarial-disorder indication and its chief role in Da Yuan Yin as evidence of the greater force. Both herbs are unambiguously warm middle-burner damp-driers; only the relative strength is in dispute. The existing comparison is left in place pending owner confirmation.

  Formulas: Cao Guo appears in Da Yuan Yin (Reach the Membrane Source Decoction — the formula for turbid damp lodged at the “membrane source” with alternating chills and fever, where Cao Guo does the defining work) and in Shi Pi Yin (Bolster the Spleen Decoction, for yang-deficiency oedema with cold-damp). (Traditional formula context, not treatment advice.)

  Naming note: the botanical name in the older literature is Amomum tsao-ko Crevost & Lemarié. A taxonomic revision moved the species to the genus Lanxangia, and recent papers publish it as Lanxangia tsaoko. Both names refer to the same plant and both are in current use; the pharmaceutical Latin recorded here follows the older convention.

  Source: Sacred Lotus sources & references (identities, nature/flavour, channels and formula compositions for all four herbs as held on file, and the recorded Cao Dou Kou comparison); cross-referenced against multiple online sources and materia medica consensus (Bensky; Chen & Chen); adulterant comparison from PMID 38735210, DOI 10.1016/j.jpba.2024.116208; genus revision usage per PMID 41054604, PMC 12496527.