Educational information, not medical advice — ask your doctor or midwife.
Xie Huang San is a herb blend used in Chinese medicine. The name is often put into English as "Drain the Yellow Powder". It is made from five herbs, most often mixed as a powder or boiled as a tea.
It has long been given for sore mouths. Old texts use it for mouth ulcers (small sores inside the mouth or on the tongue), bad breath, dry lips and thirst. It was used a lot for children.
Here is the short verdict on proof. The formula is well known and has been used for centuries, but we could not find any human trial of it. A long record of use is not the same as proof that something works.
One herb in the blend is licorice root. That matters for safety, so please read the next part before you try it.
No one has shown how this blend acts in the body. What follows is the traditional idea, plus what lab work hints at.
In Chinese medicine the formula is said to clear "heat in the Spleen and Stomach". In plain words, that is a pattern of a red, sore, dry mouth with thirst and bad breath. The herbs are picked to cool that heat without drying the person out.
Lab and animal work on single herbs points a few ways. Gardenia fruit and licorice root both calm swelling and redness in test animals. Licorice root also coats and soothes sore lining in the mouth and gut.
Those findings come from dishes and animals, not from people taking this blend. So treat the mechanism as an idea, not a fact.
You may see it as a loose powder made from the five ground herbs. This is the oldest form.
It also comes as dried granules that you stir into hot water, and as pills or capsules from Chinese herb suppliers.
Some herbalists boil the raw herbs into a tea. The blend is not usually sold as a tincture (an alcohol extract).
Amounts of each herb vary a lot between makers. Herb products are not checked as closely as drugs, so quality differs by brand.
The formula comes from a Song dynasty book on children's health, written by Qian Yi around 1119 CE. That book is one of the first works on treating children in Chinese medicine.
It still appears in standard Chinese formula textbooks today. It is best known as a children's formula for mouth sores, though adults have used it too.
Some reactions to Xie Huang San need urgent care. Call your local emergency number or go to an emergency department straight away — do not wait to see whether it passes.
Stop taking it and get urgent care the same day if your heart beats oddly, if your muscles feel very weak, or if your face, hands or ankles swell up fast. These can be signs that your potassium has dropped too low.
Call your doctor soon if your blood pressure rises, if you get bad headaches, or if you feel unwell in a way you cannot explain.
See a doctor or dentist if a mouth sore lasts more than two weeks, keeps coming back, bleeds, or comes with weight loss or a lump. A long-lasting mouth sore needs to be looked at properly.
Tell your doctor or pharmacist you are taking this blend before any surgery, and before starting any new medicine.
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 Xie Huang San 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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