Herbs & Botanicals
Indigo (qing dai)
What is indigo? What is it used for?
Indigo is a type of pigment that comes from the leaves of various plants, including isatis indigotina and polygonum tinctorium. The leaves of the plants are collected in autumn (after they fall to the ground), then soaked in water. Over time, a solution forms in the water. The solution is stirred with a type of milk until it turns from black to green to red. The solution is then dried in the sun and allowed to form a powder
In traditional Chinese medicine, indigo is considered salty and cold, and is associated with the Liver, Lung and Stomach meridians. It clears away heat, expels toxic substances, and protects the liver by purging it of fire. It is often used with other herbs, including rehmannia, tree peony, talc and licorice as part of a larger formula.
How much indigo should I take?
The typical dosage of indigo is 1.5-3 grams taken orally. Because it is rather difficult for indigo to dissolve in water, it is often taken in an infusion of boiling water. Larger amounts may be used when indigo is applied topically.
What forms of indigo are available?
Powdered indigo is available at some herbal shops. Indigo can also be taken as an extract or infusion.
What can happen if I take too much indigo? Are there any interactions I should be aware of? What precautions should I take?
Indigo should be taken with caution by people who have cold syndromes of the stomach. As of this writing, there are no known drug interactions with indigo. As always, make sure to consult with a licensed health care provider before taking indigo or any other herbal remedy or dietary supplement.
- Herb Information Center. State Drug Administration of China. A Handbook of Herb Active Components. Beijing: People's Health Press, 1986.
- Li QH. The chemical composition of qing dai. Journal of Botany 1987;29(1):67.
- Li QH, et al. Qing dai's antibacterial components. Journal of Chinese Materia Medica 1983;4(10):8.
- Sha Jing M, et al. On indirubin. Pharmacy Bulletin 1983;18(12):731.
- Zou JC, et al. Trace elements of qing dai. Journal of Pharmacy 1985;20(1):45.