What is Shi Gao? Are Sheng Shi Gao, Duan Shi Gao and Han Shui Shi the same?
Official Shi Gao (石膏) is the sulfate mineral gypsum, mainly hydrated calcium sulfate. The pharmacopoeial name is Gypsum Fibrosum. Sheng Shi Gao is crushed and decocted first: clears heat, drains fire, eliminates vexation and stops thirst. Duan Shi Gao is calcined until friable: constrains damp, generates flesh, closes sores and stops bleed—mostly external. Han Shui Shi is another mineral (red gypsum or calcite type): similar heat-clearing, not the same article. Write Sheng Shi Gao or Duan Shi Gao; do not give the calcined form internally.
What are the TCM properties and traditional uses of Shi Gao?
According to the Chinese Pharmacopoeia, raw gypsum is sweet, acrid and very cold, enters the Lung and Stomach channels, and acts to clear heat and drain fire, eliminate vexation and stop thirst. It is used for externally contracted heat disease, high fever with vexing thirst, Lung-heat wheezing cough, exuberant Stomach fire, headache and toothache. Calcined gypsum constrains damp, generates flesh, closes sores and stops bleed for unhealing ulcers, eczema, burns and traumatic bleeding. Very cold, it clears qi-aspect excess heat—suited to Yangming vigorous heat, not to Spleen-Stomach deficient cold or Blood-vacuity and Yin-vacuity fever.
How do you choose raw versus calcined gypsum? Must it be decocted first?
High fever with vexing thirst, Lung-heat wheezing cough and Stomach-fire toothache use Sheng Shi Gao, crushed and decocted first. Sores, eczema and burns use Duan Shi Gao powder externally—generally not swallowed. Being heavy and poorly soluble, it lacks force if not pre-decocted. Do not mix raw and calcined.
What is the usual dosage? Can it be drunk daily as a fire-down tea?
The pharmacopoeial decoction dose of Sheng Shi Gao is 15–60 g, preferably pre-decocted. Calcined gypsum is used externally as needed. It is not a four-season “gypsum fire-down tea.” Deficient-cold loose stool and fever without sweat or thirst only suffer more from cold. Qi-aspect excess heat needs a practitioner to name a pre-decocted dose and a short course.
What are the contraindications? Can it be used in pregnancy?
Forbid in Spleen-Stomach deficient cold and in Blood-vacuity or Yin-vacuity fever. Great cold injures Yang. High fever with vexing thirst in pregnancy needs assessment; deficient-cold fetal stirring should not take large cold doses. Excess may cause epigastric fullness, poor appetite and spirit fatigue. Lots with excess arsenic impurity risk poisoning—use regulated decoction pieces.
Can Shi Gao reduce fever, stop thirst and calm wheeze?
It can help qi-aspect excess heat. Vigorous fever, sweat, vexing thirst and a flooding large pulse join Anemarrhena, honey-fried licorice and non-glutinous rice in Bai Hu Tang. Lung-heat wheezing cough joins Ephedra, apricot kernel and licorice in Ma Xing Shi Gan Tang. It clears Lung-Stomach qi aspect—not a specific for every fever, every thirst or every asthma. Extreme fever with convulsions and respiratory failure are emergencies.
Can Shi Gao be drunk daily as a heat-clearing, whitening or anti-inflammatory tea?
Qi-aspect excess heat may enter a short formula; deficient cold without heat only grows more diarrheal. “Gypsum whitens and anti-inflames” does not replace infectious-disease and endocrine assessment. Clearing heat and draining fire should name Sheng Shi Gao (not calcined gypsum internally) and a 15–60 g pre-decocted dose.
How do you choose among Shi Gao, Zhi Mu, Han Shui Shi, Huang Qin and Jin Yin Hua?
Gypsum is sweet-acrid and very cold: clears heat, drains fire, eliminates vexation and stops thirst—clears the qi aspect while releasing the muscle. Anemarrhena is bitter-sweet-cold: clears heat, drains fire, enriches Yin and moistens dryness—clears while moistening. Han Shui Shi is acrid-salty-cold: similar fire-draining, not the same mineral. Scutellaria is bitter-cold: clears heat, dries damp, drains fire and resolves toxin—upper-jiao damp-heat. Honeysuckle is sweet-cold: clears heat, resolves toxin and courses wind-heat—warm toxin and sores. Qi-aspect vigorous heat favors Shi Gao and Zhi Mu; damp-heat favors Huang Qin; warm toxin favors Jin Yin Hua. They may be paired; all are wrong as pure great cold in Spleen-Stomach deficient cold, raw and calcined must not be swapped, and Han Shui Shi must not be called Shi Gao.
Which herbs is Shi Gao combined with? What are the representative formulas?
Qi-aspect excess heat joins Anemarrhena, honey-fried licorice and non-glutinous rice in Bai Hu Tang. Lung-heat wheezing cough joins Ephedra, apricot kernel and licorice in Ma Xing Shi Gan Tang. Residual heat injuring fluid joins bamboo leaf, ginseng, Ophiopogon, Pinellia, rice and licorice in Zhu Ye Shi Gao Tang. Write Sheng Shi Gao to pre-decoct; write Duan Shi Gao for external use.
How do you choose and store Shi Gao?
Choose large white pieces, translucent, with a silk-like luster on the longitudinal break, faint odor and bland taste; Yingcheng, Hubei lots are often preferred. Gray-yellow stone-admixed and lusterless lots are inferior. Store dry. Buy pharmacopoeial Shi Gao or Duan Shi Gao; do not replace clearing heat and draining fire with industrial gypsum or an equal weight of Han Shui Shi.
