Zhen Zhu Mu
StarPteria martensii (Dunker) / Hyriopsis cumingii (Lea) / Cristaria plicata (Leach)
Traditionally used for
- Headaches
- Dizziness
- Eye health
- Sleep
- Mood & calm
- Heart & circulation
- Skin
Cautions & contraindications
- Pregnancy
☯ TCM Properties
Calms the Liver and Subdues Yang; Calms the Spirit and Settles Fright; Clears Liver Heat and Brightens the Eyes; Brightens the Eyes and Removes Visual Obstructions; Astringes sores and stops itching (calcined form, topical)
Traditional Chinese Uses
Zhen Zhu Mu (nacre, pearl shell, mother-of-pearl) is a cool, heavy substance used to anchor Liver Yang, clear Liver Fire, calm the Shen, and brighten the eyes. It is indicated for dizziness, headache, irritability, and palpitations from rising Liver Yang or Liver Fire, as well as for anxiety, insomnia, and restlessness when heat disturbs the Heart-Shen. Topically, it treats eye inflammation and promotes healing of chronic ulcers and non-healing sores.
Pharmacological Effects
- Sedative: Oral powdered inner shell layer (0.6 or 1.2 g/kg) reduced spontaneous activity in mice, delayed cardiazol convulsions and prolonged pentobarbital sleep.
- Antiulcerative: Injection from the inner layer (5 g/kg oral or i.p.) promoted healing of acetic-acid gastric ulcer in rats; oral powder (0.6, 1.2 g/kg) inhibited stress ulcer; topical use aided skin-ulcer healing in rabbits.
- Antiallergic: Acid hydrolysate of the inner layer inhibited histamine-induced contraction of isolated guinea pig intestine and protected guinea pigs from death from histamine-induced allergic reaction.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 523.
Relationships
Full-screen graph →Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.
Botanical Description
Zhen Zhu Mu, mother-of-pearl, is the iridescent inner nacreous layer of the shells of pearl-bearing marine and freshwater bivalves, principally the marine winged pearl-oysters Pteria martensii (now Pinctada fucata martensii) and the freshwater mussels Hyriopsis cumingii and Cristaria plicata (Bivalvia, Pteriidae and Unionidae). The nacre consists of microscopic platelets of aragonite (calcium carbonate) bonded by an organic conchiolin matrix, producing the characteristic structural iridescence. The shells are harvested from cultured or wild beds, the dark prismatic outer layer is scraped or ground away to expose the smooth pearly inner surface, and the cleaned material is crushed, calcined, and ground to a fine powder, often by water-levigation. In traditional Chinese medicine the prepared substance is sweet, salty, and cold, anchoring the spirit and pacifying the Liver for palpitations, insomnia, irritability, dizziness, and headache from Liver-yang rising, and clearing the eyes for red, swollen, or blurred vision.
Active Constituents
Calcium carbonate (aragonite / calcite)
Inorganic mineral (carbonate)Concentration: ~90-95% of nacre by weight
The dominant component of nacreous shell; provides the mineral basis for the traditional antacid-like, astringent and sedative (settling) actions and supplies calcium.
Conchiolin
Structural matrix protein (scleroprotein)Concentration: ~4-6% of nacre
The organic protein matrix binding the aragonite platelets; its water-soluble protein/peptide fractions are linked to the anti-inflammatory, wound-healing and osteogenic activities reported for nacre.
Free and bound amino acids (glycine, aspartic acid, glutamic acid, alanine, etc.)
Amino acids (from conchiolin hydrolysis)Concentration: Multiple amino acids released on hydrolysis of the protein matrix
Amino acids derived from the shell protein have been proposed to contribute to sedative/calming and tissue-supportive effects.
Trace elements (magnesium, strontium, zinc, iron, manganese, copper)
Trace mineralsConcentration: Trace amounts within the carbonate matrix
Trace metals present in the nacre are cited in pharmacological reviews as possible contributors to its biological activity.
Water-soluble nacre proteins / peptides
Bioactive peptides / glycoproteinsConcentration: Minor organic fraction
Nacre protein extracts have shown, in animal models, downregulation of 5-HT3 receptors and upregulation of GABA-B, plus promotion of fibroblast migration and osteogenesis, supporting traditional sedative and wound-healing uses.
⚠ Drug Interactions
Tetracycline and fluoroquinolone antibiotics
As a calcium carbonate-rich mineral, Zhen Zhu Mu can chelate tetracyclines and fluoroquinolones in the gut (as calcium-containing antacids do), reducing their absorption and efficacy.
Clinical note: Separate administration by at least 2-4 hours from these antibiotics.
Levothyroxine
Calcium carbonate can bind levothyroxine in the gastrointestinal tract and lower its absorption, as documented for calcium supplements/antacids.
Clinical note: Take levothyroxine several hours apart from calcium-containing shell preparations.
Iron salts and oral bisphosphonates
Calcium in the shell can reduce gastrointestinal absorption of iron supplements and bisphosphonates through binding and altered gastric pH.
Clinical note: Space dosing apart from iron and bisphosphonate products.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction (pre-decocted) | 10–25 g | Daily | — | — | 中国药典 2020 【用法与用量】10～25g，先煎。 【性味与归经】咸，寒。归肝、心经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Preparation Methods
Decoction (cook first / long-decocted)
Parts: Nacreous shell layer (crushed)
The hard mineral shell is crushed and decocted first (added to the pot before other herbs and boiled longer) so the mineral matter can release; typical TCM dosing is roughly 10-30 g in decoction.
Calcined and powdered (topical)
Parts: Nacreous shell
The shell may be calcined and ground to a fine powder for external application to sores and inflamed skin for its astringent, drying and tissue-healing effect.
Fine powder (oral)
Parts: Ground nacre / pearl layer
Levigated fine powder taken in small doses or added to pills and formulas to calm the spirit and settle the Liver.
⚠ Safety & Contraindications
- Pregnancy
Contraindications
Its use is cautious in pregnant women and patients with deficiency-cold of the spleen and stomach.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 307–310.
Historical Texts
Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty (1578)Ri Hua Zi Ben Cao and later materia medica
Song dynasty and laterReferences
- Song Y, Chen W, Fu K, Wang Z. The Application of Pearls in Traditional Medicine of China and Their Chemical Constituents, Pharmacology, Toxicology, and Clinical Research . Frontiers in Pharmacology (2022) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
📝 Notes
Public notes from the community and your own private notes on Zhen Zhu Mu.
No notes yet.