Pinellia ternata (banxia): what it is and when people use it

Pinellia ternata, called banxia in traditional Chinese medicine, is the processed tuber of a small perennial plant. Practitioners use it mainly for nausea, damp-phlegm in the chest, and certain digestive complaints. You’ll see it in classic formulas like Banxia Houpo Tang and other cough or stomach blends.

How it’s prepared and why processing matters

Raw pinellia contains sharp calcium oxalate crystals that irritate the mouth and throat. For that reason the root is always processed before use — usually with ginger, alum, or licorice in traditional practice. Processing reduces the choking or burning effect and lowers acute toxicity. Don’t chew raw pinellia or use unprocessed powder; that’s the main cause of local injury reported in case reports.

Typical herbal suppliers sell it as dried, sliced, or powdered processed tuber labeled "banxia". Quality varies, so buy from a reputable TCM pharmacy and check that the product is marked as processed.

What the evidence says and real-world uses

Modern research is limited but consistent in a few areas. Animal studies show antiemetic and expectorant effects and point to anti-inflammatory activity in lung and gut tissues. Clinical data in humans are sparse but traditional use supports short-term relief for nausea, cough with thick sputum, and a feeling of fullness or nausea after eating.

In practice, pinellia is rarely given alone. It appears inside multi-herb formulas where other ingredients balance its action and reduce side effects. For example, Banxia Houpo Tang combines banxia with herbs that move qi and clear phlegm to ease throat discomfort and nausea from post-nasal drip or reflux.

When it comes to dosing, traditional sources list typical processed doses around 3–12 grams of the dried tuber per day in decoction form. Exact dosing depends on the formula, the patient, and whether it’s combined with other herbs. Always follow a trained practitioner’s recommendation.

Safety notes: avoid in pregnancy and breastfeeding unless directed by a knowledgeable clinician. People with ulcers, severe dry cough without phlegm, or recent throat injury should steer clear. Allergic reactions and local irritation can happen, especially if processing was incorrect. If you experience burning, swelling of the mouth or throat, stop use and seek care.

Want to use banxia? Talk to a licensed TCM practitioner or pharmacist who knows herbal processing and interactions. If you’re researching on your own, check product labels for the word "processed" and avoid raw tuber. Read more articles tagged with pinellia ternata to see studies, clinical uses, and safe sourcing tips on this site.