Educational information, not medical advice — ask your doctor or midwife.
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Nichinto is a traditional Japanese Kampo herbal preparation taken for a wet, phlegmy cough and for nausea, queasiness and a heavy, full feeling in the stomach. Its name means "two aged decoction", after two ingredients that were traditionally aged before use.
It is catalogued here as one single Kampo entry, because it is sold as one named preparation. It is not one plant. It combines five herbs: hange (processed pinellia root), chinpi (aged citrus peel), bukuryo (poria fungus), kanzo (licorice root) and shokyo (ginger).
The evidence verdict in one line: Nichinto has centuries of standing in East Asian medicine, but almost no modern human trials test the formula itself, and long traditional use is not proof that a remedy works.
One point matters more than any other for safety. Nichinto contains licorice, which in regular or high doses can raise blood pressure, cause swelling and push your potassium too low.
Kampo practice explains Nichinto in its own terms, not in modern biological ones. In that system it is said to move and dry "damp phlegm" that has settled in the stomach and chest, and to settle stomach energy that is rising the wrong way.
In modern terms, several plausible ideas have been studied in the laboratory rather than in people. Ginger and citrus peel are thought to speed stomach emptying and calm nausea signals. Pinellia has shown anti-nausea and cough-quieting effects in animal work.
Licorice is the best-understood part, and it is understood mainly through its harms. Glycyrrhizin, its main compound, can act like the hormone aldosterone in your body, holding on to salt and water and flushing out potassium.
None of this has been confirmed as the way Nichinto works in a person. Treat these as reasonable ideas that are still unproven.
Granulated dried extract (ekisu) is the usual modern form in Japan. It comes in single-dose sachets, is prescribed by doctors and is covered by Japanese national health insurance.
Tablets and fine powders of the same extract are sold over the counter in Japan and by Kampo suppliers elsewhere.
The classical form is a decoction: the raw sliced herbs simmered in water and strained. This is now uncommon outside specialist practice.
Home-blended loose herbs are not recommended. Getting the licorice and pinellia amounts right matters, and raw unprocessed pinellia is harmful.
Nichinto is the Japanese reading of Er Chen Tang, a formula recorded in the Chinese Song dynasty imperial formulary Taiping Huimin Heji Jufang, around 1107 CE.
It passed into Japanese Kampo practice and into Korean medicine, and has stayed in continuous use in all three for roughly nine hundred years. It is one of the base formulas that many later phlegm formulas were built from.
Today it is an officially approved Kampo prescription in Japan with a standardised extract, which is unusual standing for a herbal preparation.
Stop taking it and see a doctor promptly if your ankles, hands or face start to swell, your blood pressure rises, or you feel unusual muscle weakness, cramping or tiredness. These are the early signs of the licorice pushing your potassium too low.
Get urgent medical help if you have severe muscle pain with dark brown urine, an irregular or racing heartbeat, or yellowing of your skin or eyes.
Also see a doctor rather than continuing on your own if your cough lasts more than two to three weeks, brings up blood or green phlegm, or comes with fever or breathlessness, or if vomiting stops you keeping fluids down.
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 Nichinto 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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