Educational information, not medical advice — ask your doctor or midwife.
Gun Tan Wan is a classical Chinese herbal formula. It is also called Vaporize Phlegm Pill or Rolling Phlegm Pill. It is used to force a strong bowel movement, and in traditional terms to drive out "phlegm-fire".
It is a drastic purging formula, not a daily tonic. In traditional practice it is given for a few days at most.
This entry covers one drug: the TCM (traditional Chinese medicine) formula Gun Tan Wan. It is one fixed recipe, usually four parts. It is sold as small pills, or as a powder pressed into pills.
Now the honest verdict on the evidence. We could not find published human trials of this formula. So its traditional standing is long, but its clinical proof is more or less absent.
Traditional use tells you what people have done for centuries. It is not proof that the formula works or is safe. That point applies to everything below.
The formula holds a strong herbal laxative and a mineral part. So this is not a self-care product. Use it only with a trained practitioner who knows your full medical history and your medicine list.
The clearest and best-known action is a strong laxative one. Da Huang (rhubarb root) holds anthraquinones. These are plant compounds that irritate the bowel lining and pull water into the gut.
The result is a loose, often forceful bowel movement within hours.
In Chinese medicine, the formula is said to send "phlegm-heat" down and out in the stool. "Phlegm" there is a broad idea. It covers thick mucus, but also agitation, dizziness and confusion.
That is a traditional model, not a tested body mechanism.
Huang Qin (Chinese skullcap root) holds baicalin and related flavonoids (plant compounds). In lab studies these damp down inflammation (swelling and irritation). Whether that matters at the doses people swallow is not known.
Qing Meng Shi is a ground mineral (chlorite schist). The body takes up almost none of it. Its traditional role is to "weigh down" phlegm.
No one has shown in people that the formula does anything beyond emptying the bowel.
You will usually meet it as:
Small black or brown pills ("teapills"). This is the most common shop form.
Loose powder or granules given out by a practitioner. The recipe is sometimes changed to suit you.
Hand-made honey or water pills from a Chinese pharmacy.
It is not sold as a tea. In most practices you do not brew it at home from raw herbs.
Check that any product lists all four parts and names a maker. Mineral formulas from sources with no checks carry a real risk of being tainted with lead, mercury or arsenic.
Gun Tan Wan is credited to Wang Gui. It appears in Chinese medical texts from about the 14th century, in the Yuan dynasty. It has stayed in the standard formula set ever since.
It was grouped with the "phlegm-dispelling" formulas. It was always called strong medicine. Old texts kept it for sturdy patients with sudden, severe signs.
Classical notes warn again and again against giving it to the weak, the old or the pregnant.
It is well known within Chinese medicine and shows up in modern formula textbooks. It has no standing in any other healing tradition.
Some reactions to Gun Tan Wan 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 see a doctor straight away if you get watery diarrhoea that lasts more than a day, severe stomach pain, blood in your stool, or you cannot keep fluids down.
Get urgent help if you feel your heart pounding or skipping, your muscles go weak or floppy, you feel faint on standing, or you pass very little urine — these can be signs of low potassium or dehydration.
Get urgent help if the whites of your eyes or your skin turn yellow, or your urine stays dark, which can point to liver trouble.
See a doctor rather than treating yourself if a cough lasts more than three weeks, brings up blood, or comes with fever or breathlessness. Sudden confusion, agitation or a first seizure needs emergency care, not a herbal formula.
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 Gun Tan Wan 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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