Mang Xiao (Natrii Sulfas, Glauber’s salt, or Mirabilite)

What Is Mang Xiao

Mang Xiao is also known as Natrii Sulfas, Glauber’s salt, or Mirabilite and is a hydrous sodium sulfate mineral. It is a natural laxative and belongs to mineral medicines, which first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (about 100 BC).

This kind of ore is mostly produced in coastal alkaline land areas, mineral springs, salt fields, and moist caves. Its main production countries are the United States, Canada, Mexico, Spain, Russia, and China.

Two-thirds of the world’s production of Mang Xiao is from natural mirabilite. Its annual output is about 600 tons, which can be synthesized artificially.

Mang Xiao is unstable and quickly dehydrates in dry air, the prismatic crystals turning into a white powder, thenardite (Na2SO4). In turn, thenardite can also absorb water and convert to Mang Xiao.

Thenardite is an important basic chemical raw material, which is widely used in the fields of washing, bleaching, papermaking, glass, leather, synthetic fibers, inks, and rubber.

Mirabilite can be collected at any time of the year, but it is better in winter. People dissolve natural mirabilite in hot water, filter, and cool to obtain crystals. Then, boil it with the sliced white radishes, filter out their filtrates, and cool again to obtain crystals. In traditional Chinese medicine technology, it can be combined with watermelon to make Xi Gua Shuang (Watermelon Frost).

Mang Xiao mainly contains hydrous sodium sulfate, as well as a small number of inorganic salts such as sodium chloride, magnesium sulfate, and calcium sulfate. Generally, colorless and transparent Mang Xiao with a glassy gloss cross-section is the best.

According to <Yao Pin Hua Yi> (Genuine book Drugs of Justice), the medicinal property of Mang Xiao is relatively cold, with a salty and bitter taste. It has a certain therapeutic effect on the pathological changes of the stomach and large intestine meridians.

In traditional Chinese medicine, Mang Xiao is often used to relieve constipation and eliminate accumulation, moisten dryness and soften dry stool, clear heat and reduce swelling, treat cholelithiasis, sore throat, aphtha, hemorrhoids, paint dermatitis, Kashin-Beck disease, acute eczema, urolithiasis, mumps, biliary ascariasis, and intractable skin itching.

There are about 50 kinds of Chinese medicine prescriptions containing it, such as Tiao Wei Cheng Qi Tang, Fang Feng Tong Sheng San, and Da Huang Mu Dan Tang.


  • Anti-inflammation, inhibiting xylene-induced ear swelling in mice.
  • Eliminating accumulation, treating constipation caused by sthenic fever accumulation.
  • Moistening dryness, softening dry stool, and hard mass.
  • Clearing heat, relieving sore throat, mouth sores, tongue sores, and inflamed eyes.
  • Relieving acute swelling and pain of hemorrhoids and abdominal pain caused by early intestinal carbuncle.
  • Relieving headaches caused by wind-heat or blood stasis.
  • External application on the breast can wean, relieve physiological milk swelling, and eliminate breast lumps.
  • The sulfate ion is not easily absorbed by the intestinal mucosa. It will form a hypertonic salt solution in the intestine, which prevents the absorption of water in the intestine, increases the volume of the intestine, stimulates intestinal motility, and promotes urination and defecation.
  • Clinically, it is often used to relieve abdominal pain and constipation caused by cholelithiasis.


Side Effects

Although Mang Xiao is generally regarded as non-toxic, it should be handled with care.

Its powder can cause temporary asthma or eye irritation.

Overdose it may cause nausea, vomiting, abdominal pain, diarrhea, or prostration.

Precautions and Warnings

  • The dosage of Mang Xiao should be controlled at 10-15g.
  • It can be made into pills, eye drops, powders, and is rarely made into decoction.
  • It is recommended to dissolve it in decoction or boiling water before taking it orally or grind it for external use.
  • People who are allergic to Mang Xiao should not take it.
  • It should not be used with spironolactone, Liu Huang (Sulfur), or San Leng (Rhizoma Sparganii).
  • Patients with renal insufficiency should not take it.
  • Pregnant and breastfeeding women should not take it.
  • Children, the elderly, and the infirm should not take it.
  • It should be kept in airtight condition below 30°C.