Long Dan Cao (Chinese Gentian Root)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Long Dan Cao?

  Commonly 3–9 g in decoction, the range given in Sacred Lotus sources & references and consistent with standard materia medica. Because it is so intensely bitter and cold, it is generally used at the lower end of the range and for a limited course, and is often combined with Stomach-protecting herbs when part of a larger formula.

  • Part used — the dried root and rhizome.
  • Preparation note — a wine-processed (stir-fried in wine) form is sometimes used to moderate the herb's coldness for headache/dizziness patterns while retaining its fire-draining action; raw Long Dan Cao is preferred for stronger damp-heat/fire-toxin presentations.

  Source: Sacred Lotus sources & references; cross-referenced against multiple online sources. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Long Dan Cao?

  Long Dan Cao is contraindicated in Spleen/Stomach deficiency and in patients prone to diarrhea or poor appetite. Its extreme bitterness and cold nature make it one of the more digestion-taxing herbs in the materia medica — used inappropriately or for too long, it can injure Spleen-Stomach qi and cause loose stools, poor appetite, or epigastric discomfort.

  • Spleen/Stomach deficiency, diarrhea, or poor appetite — avoid or use only briefly and with protective herbs.
  • Not for prolonged use — traditionally reserved for clear excess-fire/damp-heat patterns, not maintenance use.
  • Pregnancy — use only under a qualified practitioner given its cold, draining nature.

  Source: Sacred Lotus sources & references; cross-referenced against multiple online sources.

Chinese Herb Toxicity & Overdose

• Low acute toxicity at traditional doses, but poorly tolerated by weak digestion. Long Dan Cao is not considered a toxic herb in the classical sense (it carries no special processing or dose-ceiling requirement in Sacred Lotus sources & references), but its intense bitter-cold nature means the main real-world risk is gastrointestinal — nausea, loose stools, or appetite loss — from excess dose, prolonged use, or use in a Spleen/Stomach-deficient patient, rather than systemic toxicity.

  Source: Sacred Lotus sources & references; cross-referenced against multiple online sources. Reference note, not a safety guarantee.

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 Long Dan Cao (Gentiana scabra)?

  Yes — mostly preclinical (cell and animal) research on gentiopicroside and related iridoid glycosides, the plant's principal bitter constituents. Human clinical trial evidence specific to Long Dan Cao itself remains limited.

  • Hepatoprotective activity (preclinical) — gentiopicroside has shown protective effects against chemically- and drug-induced liver injury (including alcohol- and immunosuppressant-related models) in animal studies, largely via antioxidant and anti-inflammatory mechanisms.
  • Anti-inflammatory / anti-arthritic (preclinical) — gentiopicroside combined with conventional anti-rheumatic drugs reduced drug-induced liver injury in an arthritic rat model, alongside anti-inflammatory effects.
  • Broader pharmacology review — a 2024 pharmacological review describes gentiopicroside's hepatoprotective, anti-arthritic/analgesic, antidiabetic, and anticancer activities across cell and animal studies, concluding it shows generally low toxicity but needs further human safety and bioavailability research.

  This preclinical work is consistent with, but does not clinically prove, the herb's traditional heat-clearing/damp-draining use; it should be read as research context only.

  Sources: PMID 33130083 (gentiopicroside, arthritic rat liver-injury model); PMID 39714353 (Chemistry & Biodiversity, pharmacological activities review); PMID 37632552 (Naunyn-Schmiedeberg's Archives of Pharmacology, mechanisms review). Preclinical research context, not a therapeutic claim.

Chinese Herb Notes

• How is Long Dan Cao different from Qin Jiao?

  Long Dan Cao and Qin Jiao are both roots from plants in the genus Gentiana, but they treat opposite ends of the pattern spectrum and are not interchangeable. The shared genus and similar-sounding names (both are commonly called "gentian" in English) are a frequent source of confusion.

  • Long Dan Cao (Gentiana scabra, Radix Gentianae) — intensely bitter and cold; drains repletion (excess) fire and damp-heat from the Liver/Gallbladder. Used for hot, inflamed, excess-type presentations.
  • Qin Jiao (Gentiana macrophylla, Radix Gentianae Macrophyllae) — classified among the herbs that dispel wind-dampness; it relieves joint and body pain (Bi syndrome) regardless of hot or cold nature, and separately clears deficiency-type (yin-deficient, "bone-steaming") heat. It is comparatively mild and non-drying, and does not share Long Dan Cao's strong fire-draining, damp-heat-clearing action.

  Key combinations (Long Dan Xie Gan Tang): Long Dan Cao is the chief herb of Long Dan Xie Gan Tang, classically combined with Huang Qin and Zhi Zi (to reinforce heat-clearing), Ze Xie, Che Qian Zi and Mu Tong-type herbs (to drain damp-heat via urination), Dang Gui and Sheng Di Huang (to protect yin/blood from the drying bitter-cold herbs), and Chai Hu with Gan Cao (to guide the formula into the Liver/Gallbladder channel and harmonize). (Traditional formula context, not treatment advice.)

  Source: Sacred Lotus sources & references (formula link: Long Dan Xie Gan Tang); cross-referenced against multiple online sources.