This product is the shell or pearl layer of bivalve mollusks, including the triangular sail mussel (Hyriopsis cumingii (Lea)) and the rice-patterned crown mussel (Cristaria plicata (Leach)), as well as pearl oysters such as the pearl oyster (Pteria margaritifera (L.)) and the Martens' pearl oyster (Pteria martensii (Dunker)). The triangular sail mussel and the rice-patterned crown mussel are found in rivers, lakes, and marshes across the country, while the pearl oyster and Martens' pearl oyster are mainly produced in Hainan Island, Guangdong, and Guangxi coastal areas. They can be harvested year-round. After removing the flesh, the shells are boiled in alkaline water, rinsed, the outer black layer is scraped off, and then dried. They can be used raw or calcined. Crush before use.

bubble_chart Properties and Meridians

Salty, cold. act on liver and heart channels.

bubble_chart Efficacy

Pacifying liver and subduing yang, clearing heat and improving vision, setting heart and calming mind.

bubble_chart Indications

1. Used for ascendant hyperactivity of liver yang, dizziness, and dizzy vision. Nacre has similar effects to Abalone Shell in pacifying the liver and subduing yang, as well as clearing liver fire. It is often used in combination with oyster shell, Peony Root, Magnetite, and other liver-pacifying medicinals to treat liver yang vertigo, headache, and tinnitus. If there is ascendant hyperactivity of liver yang accompanied by liver heat dysphoria and irritability, it can be combined with Uncaria, Chrysanthemum Flower, Prunella, and other heat-clearing liver medicinals.
2. Used for red eye swelling and blurred vision. This product is salty and cold in nature, and also has the effect of clearing liver heat and improving vision. It is used to treat liver heat red eye and nebula, often combined with Abalone Shell, Chrysanthemum Flower, Plantain Seed, to clear heat and improve vision, and reduce nebula. For liver deficiency with dim vision and blurred vision, it is combined with Barbary Wolfberry Fruit, Lycium Fruit, black sesame, and other medicinals to nourish blood and improve vision. If cooked with Atractylodes Rhizome and pig or chicken liver, it can treat night blindness (nyctalopia).
3. Used for palpitation due to fright, insomnia, and restlessness. This product is heavy in nature and enters the heart, and also has the effect of calming the heart and tranquilizing the spirit. It can be combined with Cinnabar, Fossil Bone, amber, and other tranquilizing medicinals to treat palpitation, insomnia, and restlessness. It can also be combined with Gastrodia Tuber, Uncaria, Arisaema, and other wind-extinguishing and convulsion-relieving medicinals to treat epilepsy and infantile convulsions.
4. In addition, when ground into a fine powder and applied externally, it can dry dampness and astringe sores, and is used for eczema and cutaneous pruritus. In recent years, pearl powder has been taken orally to treat gastric and duodenal ulcers, or made into eye ointment for external use to treat internal visual obstruction, keratitis, and conjunctivitis, with considerable efficacy.

bubble_chart Documentation

1. "Chinese Medical Dictionary": "Nourishes liver yin, clears liver heat. Treats manic and depressive psychosis, fright epilepsy, dizziness, tinnitus, palpitations, chest and abdominal distension and fullness, women's blood heat, menorrhagia, and children's convulsions and spasms."
2. Yinpian Xincan: "Pacifies the liver and subdues yang, calms the spirit, stabilizes fright epilepsy, eliminates heat fullness, and eye nebula."

bubble_chart Usage and Dosage

Decoct 15-30g, crush before use. For external use, apply an appropriate amount.

bubble_chart Modern Pharmacology

This product contains more than 90% calcium carbonate and approximately 0.34% organic matter; it also contains small amounts of magnesium, iron, silicates, sulfates, phosphates, and oxides, as well as various amino acids.

• The active ingredient, calcium carbonate, can neutralize stomach acid.
• The 30% sulfuric acid hydrolysate of nacre can increase the amplitude of heartbeat in isolated hearts;
• the ether extract can inhibit the contraction of isolated intestines and uterus, and prevent histamine-induced shock and death in guinea pigs;
• nacre has a protective effect on liver injury caused by carbon tetrachloride.