Isatis root
Isatis tinctoria · 板蓝根
Herbs & Roots. Chinese Medicine.
Also called Ban lan gen, Woad root, Dyer's woad, Isatis root
Pinyin: Bǎn lán gēn
Allergic reactions reportedThe root of a mustard-family plant, used in Chinese medicine for sore throat, fever and flu-like illness.
Did you know? The same plant, woad, was Europe's main source of blue dye for centuries until indigo arrived from Asia.
What it may help, and how strong the proof is
- Infections. Lab studies show activity against some flu viruses and bacteria. Human trials are few and small.Traditional proof
- Sore throat & cough. Used in tradition for sore throat. Human trials are lacking or poorly reported.Traditional proof
- Fever. Used in tradition for fevers. Few good human trials exist.Traditional proof
Parts of the body
Traditional use
Traditional Chinese Medicine has used isatis root for fever, sore throat and flu-like illness, especially in the cold season.
How it is classified
- Herbal actions
- Antiviral, Antimicrobial, Anti-inflammatory. Energy: cooling.
- Chinese medicine
- 板蓝根 Clear heat. Nature: cold. Flavour: bitter. Enters the Heart and Stomach channels.
How people take it
Traditional doses are about 9 to 15 grams of dried root in a decoction. Ready-made granules are common in China and should be taken as the label says.
Decoction, tea and capsule.
Where to get it
Grows in northern China and across Eurasia. Dried root is sold in Asian herb shops, and as granules. The plant was historically grown as a dye crop.
Be careful
Generally mild when taken by mouth. Allergic reactions have been reported with some ready-made products. Avoid it in pregnancy because data are limited.
Avoid if: pregnancy; mustard family allergy.
Mixing with other things
- Works well together
Both clear heat and toxins. They are often combined in Chinese practice for throat and flu-like infections, but no trial has tested the pairing.
- Works well together
Often combined with honeysuckle for sore throat and fever in Chinese practice. No trial has tested these pairings.
- Works well together
Both are used together in Chinese practice for lung and throat infections, though no trial has tested the pairing.
The honest take
Isatis root is a common cold-season herb in China, and lab studies show antiviral activity. Good human trials are scarce, and most ready-made products have been tested only in small or low-quality studies. Claims that it prevents flu are unproven.