Long Dan Cao (龙胆草): The Fierce Herb That Quenches Liver and Gallbladder Fire
Learn about Long Dan Cao (Gentiana), one of TCM's most potent heat-clearing herbs. Discover its bitter-cold properties, its role in the famous Long Dan Xie Gan Tang, and clinical applications for Liver fire, damp-heat, and eye disorders.
Long Dan Cao: Bitter Cold, Fiercely Effective
Long Dan Cao (龙胆草, Lóng Dǎn Cǎo), or Chinese Gentiana root, is one of the most intensely bitter and cold herbs in the TCM materia medica. Its Chinese name — “Dragon Gallbladder Herb” — captures both its extraordinary bitterness (rivaling animal bile) and its primary affinity for the Liver and Gallbladder channels. In the right pattern, it is a remarkably effective herb; used carelessly, its extreme coldness can damage the Spleen and Stomach.
The herb is the dried root and rhizome of Gentiana scabra, Gentiana triflora, or Gentiana manshurica, harvested in autumn when its medicinal properties peak.
Properties and Channel Entry
| Property | Description |
|---|---|
| Taste | Extremely bitter |
| Temperature | Cold |
| Channels Entered | Liver, Gallbladder |
The overwhelming bitterness gives Long Dan Cao its powerful heat-clearing and damp-drying properties. Its cold nature directly counters fire and heat. Its exclusive channel affinity for Liver and Gallbladder makes it a specialist — it targets these two organs with remarkable precision.
Key Functions
1. Clears Liver and Gallbladder Fire (清肝胆火)
Long Dan Cao is the strongest herb for clearing real fire from the Liver and Gallbladder:
- Red, swollen, painful eyes — Liver fire blazing upward to the eyes, with bloodshot sclera, photophobia, and a burning sensation
- Severe headaches — especially at the temples and sides of the head, throbbing and intense
- Bitter taste in the mouth — persistent bitterness, especially in the morning
- Irritability and rage — Liver fire pushing the emotions to extremes, short temper, aggressive outbursts
- Tinnitus with sudden onset — loud, roaring ear noise from fire rising upward
2. Clears Damp-Heat in the Lower Jiao (清下焦湿热)
Beyond fire, Long Dan Cao also addresses damp-heat pouring downward:
- Vaginal discharge with odor — yellow, thick, burning (damp-heat in the Lower Jiao)
- Genital itching and swelling — especially in damp-heat conditions
- Painful, burning urination — damp-heat in the Bladder
- Scrotal swelling and dampness — Liver channel damp-heat
3. Clears Liver Heat for Eye Disorders (清肝明目)
Because the Liver opens into the eyes, Long Dan Cao is valuable for:
- Acute conjunctivitis — red, swollen, painful eyes with discharge
- Acute glaucoma — elevated eye pressure with pain and redness (as adjunctive therapy)
- Uveitis — inflammatory eye conditions with heat signs
The Signature Formula: Long Dan Xie Gan Tang
Long Dan Cao is best known as the king herb in Long Dan Xie Gan Tang (龙胆泻肝汤), one of the most important formulas in the TCM pharmacopoeia for draining Liver and Gallbladder damp-heat:
| Herb | Role |
|---|---|
| Long Dan Cao (king) + Huang Qin + Zhi Zi | Clear and drain Liver-Gallbladder fire |
| Ze Xie + Mu Tong + Che Qian Zi | Drain damp-heat downward through urination |
| Sheng Di Huang + Dang Gui | Protect Yin and blood from the harsh cold-drying herbs |
| Chai Hu | Guide the formula to the Liver and Gallbladder channels |
| Gan Cao | Harmonize and protect the Spleen |
The formula is a masterclass in balancing strength with safety: powerful heat-draining herbs are buffered by Yin-nourishing and Spleen-protecting assistants.
Dosage and Preparation
- Standard dose: 3–6 grams in decoction
- Maximum safe dose: Generally not exceeding 9 grams
- Always used in combination — rarely prescribed alone due to its harshness
Important Precautions
Long Dan Cao’s extreme bitter-cold nature demands respect:
- Do not use in Spleen/Stomach deficiency — patients with loose stools, poor appetite, cold abdomen, or a pale tongue
- Short-term use only — prolonged use damages the Spleen and Stomach, causing nausea, diarrhea, and loss of appetite
- Not for Yin deficiency heat — this herb is for real/excess fire, not the empty heat of Yin deficiency
- Pregnancy contraindication — its cold, descending nature poses risks
- Monitor digestion closely — if the patient develops stomach pain or diarrhea, reduce the dose or discontinue
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FAQ
Who is this article for?
Readers who want to understand one of TCM's most powerful heat-clearing herbs and its role in treating Liver fire, eye inflammation, and damp-heat conditions.
Can this article replace professional medical advice?
No. This content is educational only and should not replace diagnosis or treatment from a qualified healthcare professional.
Disclaimer
This content is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment.