Educational information, not medical advice — ask your doctor or midwife.
Jahwa-jeonho is the dried root of the plant Angelica decursiva, used on its own as a single herb in Korean medicine. In English it is called purple-flowered hogfennel root. It is used most often in teas aimed at a wet, rattling cough with thick phlegm (mucus).
In traditional practice it is given to "clear" the lungs and settle a cough that comes with a fever, a stuffy chest or a heavy head. Practitioners usually boil it with other herbs rather than give it alone.
Here is the honest verdict on the evidence. Jahwa-jeonho has a long record of traditional use, but almost all modern study is in test tubes and animals. Long use in a tradition is not proof that something works in the body, and that point applies to everything on this page.
No one has shown how jahwa-jeonho works in people. What follows is a best guess from lab work, not a proven path.
The root is rich in coumarins, a family of plant compounds. In cell and animal studies these compounds calm inflammation (swelling and irritation) and relax airway muscle. That could, in theory, loosen phlegm and ease a tight chest.
In Korean and Chinese theory the root is said to push "wind-heat" out and send stuck lung energy downward. That is a traditional way of describing a pattern of symptoms, not a body process anyone has measured.
Cut and dried root slices for boiling into a tea are the traditional form, and the one with the longest record of use.
You may also see it as a powder, as granules that dissolve in hot water, or in a liquid extract. It is often blended with other herbs in a prepared formula rather than sold alone.
Some products sold as "jeonho" use a related plant, Peucedanum praeruptorum. Check the Latin name on the label if you want Angelica decursiva.
Jahwa-jeonho has been used in Korean herbal medicine for centuries and appears in the shared East Asian materia medica under the name jeonho.
It is grouped with herbs given for coughs with phlegm, usually in a boiled blend with other roots and barks. It is a recognised part of the tradition rather than a headline herb.
See a doctor if your cough lasts longer than three weeks, or if it comes back after it clears.
Get urgent help if you cough up blood, cannot catch your breath, have chest pain, or have a high fever that will not settle.
Stop the herb and call your doctor if you bruise easily, bleed from the gums or nose, get a bad sunburn from ordinary sunlight, or come out in a rash.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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