Educational information, not medical advice — ask your doctor or midwife.
Jiinkokato is a set herb mix used in Kampo, the herbal medicine of Japan. It is a single drug (Kampo). That means it is one fixed mix, taken on its own, rather than blended with other mixes.
Its old name is Yin-Nourishing Fire-Descending Decoction. Kampo uses it for a dry cough that has gone on for weeks or months. The cough is often worse at night, with little or no phlegm.
The proof is weak. The mix has a long past in Kampo, but we found no good human trials for it. A long history of use is not proof that a herb works.
No one has shown how Jiinkokato works in the body. What follows is theory, not proof.
Kampo reads this kind of cough as yin deficiency (a dry, worn-out state with too little body fluid). The mix is meant to add moisture and cool that dryness. The moistening herbs are rehmannia, asparagus root and ophiopogon.
Lab tests hint that some of these herbs calm coughing and soothe dry tissue. That work is in cells and animals only. It does not show that the whole mix helps people.
In Japan the common form is a dried extract granule, sold in sachets. Tablets, capsules and loose powder are also made.
The oldest form is a decoction (a tea made by boiling the raw herbs in water for about 30 minutes). Some Kampo practitioners still prepare it this way.
Strength differs a lot between makers. Check the label for how much licorice each daily dose holds.
The recipe comes from a Chinese text of 1587, Wanbing Huichun, written by Gong Tingxian. Japanese doctors took it up during the Edo period and it became part of Kampo practice.
It was long given to people with a dry, wasting cough, including cough from tuberculosis in the years before drug treatment. Today it is one of the Kampo extract mixes approved and sold in Japan.
See a doctor before you start if your cough has lasted more than three weeks, or if you cough up blood, lose weight without trying, sweat at night, run a fever, or feel short of breath.
Stop taking it and get medical help the same day if you swell in the face, hands or legs, gain weight fast, feel weak or cramped in your muscles, or feel your heart race or skip.
Get urgent help if your skin or eyes turn yellow, your urine goes dark, or you become suddenly breathless with fever. These can be signs of liver or lung harm.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
Reviewed by the HealisticMD editorial team How we grade evidence →
The published evidence for Jiinkokato is weak or absent. That usually means no controlled trial has tested it, not that a trial found it ineffective — the two are different, and we grade only what has been published.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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