Hyriopsis cumingii (Zhenzhumu)

Distribution:
Mainly produced along the sea of Hainan, Guangdong, and Guangxi provinces of China.
Schistodesmus lampreyanus Baird & Adams is mainly produced in the valley Yangtze River and in rivers of Northern China.
 
Properties (characteristics):
Salty, cold.
 
Channels (meridians) entered:
Liver, heart.
 
Medical functions:
Inhibits formation of cataract, protect liver, anti-ulcer, sedating, anti-seizure, cardiac stimulating, anti-allergy.

Actions & Indications:
Being used in irritability, Epilepsy, sore and swollen throat, gum diseases, chronic ulcers, dizziness, Headache, Tinnitus, cataract, night blindness, blurring of vision,  Insomnia, Palpitation, forgetfulness, Peptic Ulcer, hypertension. 
 
Chemical ingredients:
In a study, the shell of Schistodesmus lampreyanus contains calcium carbonate >90%, organic substances 0.34%, and small amount of magnesium, iron, silicates, sulfates, phosphates, and chlorides. The organic portion contains glycine, alanine, valine, methionine, cystine, arginine, histidine, threonine, tyrosine, aspartic acid, glutamic acid, etc..After shells are burnt, the calcium carbonate is broken down and produced calcium oxide and the organic material becomes damaged.

Dosage:
15 to 30 g. (boil it longer than other herb)
 
Cautions:
No to use in cases of qi deficient/ weak cardiac function with edema.