English Name: sodium sulfate, mirabilite
Pharmaceutical Name: Natrii Sulfas
Medica Category: Downward Draining Herbs– Purgatives
Properties: Mang Xiao enters the Lung, Stomach, and Large Intestine channels; it is salty and bitter in nature and cold in temperature.
The Chinese Herb Mang Xiao (aka Glauber’s salt) is a kind of mineral salt that is deposited as water in a lake or pond evaporates and leaves it behind; deposits also occur underground and are mined. In TCM, Mang Xiao is dissolved in hot water/decoctions (usually paired with Da Huang) where its function is to soften the stool and treat constipation through its osmotic effect (see below).
Mang Xiao purges excess (i.e. stagnation), drains heats, and moistens the intestines (by pulling water in through osmosis) to address constipation that is characterized by dry, hard stools. It can also be used topically to clear heat and soften hardness to address nodules, abscesses, and other swellings.
Mang Xiao clears the heat/fire that is caused by phlegm stagnation. In the Lung this condition is characterized by a cough with sticky, difficult to expectorate, yellow sputum, dyspnea, and possibly swelling and pain in the upper body. Phlegm stagnation and excess heat in the Heart channel (i.e. phlegm misting the Heart) may manifest as confusion, palpitations, anxiety, and in severe cases mania and delirium.
Contraindicated in persons with deficiency and cold in the Spleen and Stomach.
Contraindicated during pregnancy.
Topical use for breast abscesses with a lactating mother may lead to decreased (or termination of) lactation.
Xuan Ming Fen (Natrii Sulfas Exsiccatusis) a purer form of sodium sulfate; it is less effective as a laxative but more effective topically for ulcers of the mouth and can be administered internally in formula to reduce swellings and dissipate nodules.