Pith of Common Rush (Deng Xin Cao)
Pith of Common Rush (灯心草, Dēng Xīn Cǎo)
Pith of Common Rush, or Dēng Xīn Cǎo, is the dried pith of Juncus effusus, a plant commonly found in wetlands. In Traditional Chinese Medicine (TCM), it is known for its cooling and diuretic properties.
Functions & Uses in TCM:
- Promotes Urination & Drains Dampness – Often used for treating urinary difficulty, painful urination, and edema.
- Clears Heart Heat & Calms the Spirit – Helps with irritability, restlessness, and insomnia caused by heat disturbing the Heart.
- Guides Heat Downward – Used in conditions where excessive heat needs to be directed downward to balance the body’s energy.
Common Formulations:
- Typically combined with Mu Tong (木通, Akebia Caulis) and Dan Zhu Ye (淡竹叶, Lophatherum Herb) for urinary issues.
- Can be included in herbal teas or decoctions for clearing heat and calming the mind.
Dosage & Preparation:
- Dosage: 1.5–4.5 grams in decoction.
- Often steeped in hot water like tea or boiled into herbal formulas.
Precautions:
- Not suitable for individuals with deficiency and cold conditions.
- Use with caution during pregnancy.
Formula: Dao Chi San (导赤散, Guide Out the Red Powder)
This formula is used for clearing Heart heat and promoting urination. It’s especially helpful for symptoms like irritability, mouth sores, thirst, dark or painful urination (heat in the Heart and Small Intestine channels).
Ingredients:
- Sheng Di Huang (生地黄, Rehmannia Root) – 6-9g → Nourishes Yin, clears heat
- Mu Tong (木通, Akebia Caulis) – 3-6g → Promotes urination, clears Heart heat
- Dan Zhu Ye (淡竹叶, Lophatherum Herb) – 3-6g → Clears heat, relieves irritability
- Dēng Xīn Cǎo (灯心草, Pith of Common Rush) – 1.5-3g → Clears Heart heat, guides heat downward via urination
Preparation & Dosage:
- Decoction: Boil the herbs in water for 15–20 minutes, then drink the strained liquid.
- Dosage: 1–2 times daily, depending on severity.
Indications:
- Irritability, restlessness
- Mouth sores or ulcers due to Heart heat
- Dark, scanty, painful urination
- Thirst with a strong desire for cold drinks
Cautions:
- Avoid in cases of Spleen & Stomach Qi deficiency with loose stools or cold patterns.
- Use with caution in pregnancy.
For example:
- For severe urinary discomfort → Add Che Qian Zi (车前子, Plantago Seeds) for stronger diuretic action.
- For insomnia & anxiety → Combine with Suan Zao Ren (酸枣仁, Ziziphus Seed) and Bai Zi Ren (柏子仁, Biota Seed).
- For mouth sores & severe heat → Increase Sheng Di Huang (生地黄) and add Huang Lian (黄连, Coptis Root).