Liang Ge San
Quick Facts
- What it is: A single drug in the sense used here: one classical Chinese herbal formula, Cool the Diaphragm Powder, built around rhubarb root and a mineral salt to move the bowels and clear what tradition calls upper-body heat.
- Main uses: Constipation with fever or feeling overheated, Sore throat and mouth ulcers with constipation, Irritability and thirst in a heat pattern
- Best for: Short-term use for constipation that comes with feeling hot and dry, Use under a qualified practitioner rather than self-prescribed
- Active ingredients: Da Huang (rhubarb root) anthraquinones, Mang Xiao (Glauber's salt, sodium sulfate), Zhi Zi (gardenia fruit), Huang Qin (Chinese skullcap root), Lian Qiao (forsythia fruit), Bo He (mint leaf), Gan Cao (licorice root), source of glycyrrhizin
- Forms: Loose powder for decoction, Granules, Concentrated pills or tablets
- Time to effect: Bowel movement usually within 6 to 12 hours; other traditional effects, if any, over one to three days.
- Side effects: Cramping and loose stools are expected; dehydration, low potassium and raised blood pressure are the real risks with longer use.
Track this remedy in the app
Track Liang Ge San with reminders and record whether it helped, in the app.
What is Liang Ge San?
Liang Ge San is a classical Chinese herbal formula, also known as Cool the Diaphragm Powder. This entry covers a single drug (a TCM formula), not a single herb. It is a purgative mixture, meaning it works mainly by moving the bowels.
In traditional Chinese medicine it is used for what practitioners call "heat in the chest and diaphragm": a dry mouth, sore throat, mouth ulcers, irritability, thirst, a red face and constipation, often with a fever. It is meant as a short, sharp intervention, not a daily tonic.
On the evidence: there is a long and well-documented record of traditional use, but almost no published human trial evidence in English for the formula itself. Traditional use tells you what people have done for centuries; it is not proof that a remedy works. Anything here about tradition should be read that way throughout the page.
How does Liang Ge San work?
The clearest and best-understood effect is a laxative one. Da Huang (rhubarb root) and Mang Xiao (Glauber's salt, a sulfate mineral salt) both move the bowels, one by stimulating the gut wall and one by pulling water into the gut.
Traditional theory frames this differently. It says the formula drains "heat" downward and out through the stool, while lighter herbs such as Bo He (mint) and Lian Qiao (forsythia) clear heat from the upper body.
Laboratory work on the individual herbs shows anti-inflammatory and antibacterial activity in cells and animals. That is not the same as showing the finished formula helps a person, and nobody should read it that way.
What forms does Liang Ge San come in?
You will meet it in a few forms:
Loose powdered herbs, decocted (simmered in water) with honey and fresh bamboo leaf, which is the classical method. Ready-made granules that dissolve in hot water. Concentrated pills or tablets from Chinese patent medicine makers.
Strength varies a lot between products, because the ratio of rhubarb and Glauber's salt is not standardised across brands. Two products with the same name can act very differently on your bowels.
Where it comes from:
Liang Ge San first appears in the Taiping Huimin Heji Ju Fang, the imperial formulary of the Song dynasty, compiled in the early 1100s. It has stayed in continuous use in Chinese medicine for roughly 900 years and is taught in every standard formula textbook.
It sits in the category of "formulas that drain downward", grouped with other purgatives. Its standing is inside one tradition, Chinese medicine, rather than across several.
Who should avoid Liang Ge San?
- Do not use if you are pregnant. This formula is a strong purgative and can stimulate the womb; it is not safe at any stage of pregnancy.
- Do not use if you are breastfeeding, as the laxative compounds can pass into breast milk.
- Do not use if you are giving it to a child, unless a qualified practitioner has prescribed it for that child.
- Do not use if you have inflammatory bowel disease such as Crohn's disease or ulcerative colitis (long-term inflammation of the gut), or a blocked bowel.
- Do not use if you have ongoing diarrhoea, are dehydrated, or are recovering from vomiting and fluid loss.
- Do not use if you have low potassium (a mineral imbalance that can upset the heart rhythm) or take medicine for an irregular heartbeat, including digoxin.
- Do not use if you take a diuretic (water tablet), a corticosteroid such as prednisolone, or lithium, unless your doctor has checked it first.
- Do not use if you have high blood pressure, heart failure or kidney disease, because the licorice in it can hold on to salt and water.
- Do not use if you are frail or elderly and prone to dehydration, unless a practitioner is supervising you.
- Do not use if you are taking warfarin or another blood thinner, unless your doctor is monitoring your clotting tests.
- Do not use if you have a cold, chills and no fever, which in traditional terms is the opposite pattern to the one this formula treats.
When should you see a doctor?
Stop taking it and get medical advice if the diarrhoea is severe, lasts more than two days, or you cannot keep fluids down.
See a doctor promptly if you feel weak, dizzy, confused, or notice muscle cramps or a fluttering or racing heartbeat. These can be signs of dehydration or low potassium.
Go to an emergency department for severe stomach pain, blood in the stool, black tarry stools, or vomiting that will not stop. Also see a doctor if a fever lasts more than three days, if a sore throat makes swallowing or breathing hard, or if constipation keeps coming back rather than treating it again yourself.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
4.8
