Clam Shell — Safety & Interactions
Ge Qiao · Concha Meretricis Seu Cyclinae
Use with caution. Practitioner review recommended before use.
Contraindications
- Lung deficiency-cold or clear-sputum cough without phlegm-heat
- Yang deficiency and weak digestion when there is no phlegm-heat, nodulation, or excess acidity to justify shell use
Cautions
- Like other calcium-rich shell medicinals, Ge Qiao can interfere with absorption of some medications if taken at the same time.
- Raw versus calcined form matters clinically: raw shell is more often used for phlegm-heat and nodules, while calcined shell is more aligned with antacid use.
- Only properly cleaned medicinal shell should be used because shell materials can carry contamination if poorly sourced or processed.
Drug Interactions
| Drug Class / Substrate | Mechanism | Severity | Source |
|---|---|---|---|
| Fluoroquinolone antibiotics - calcium-rich shell minerals can reduce drug absorption; separate dosing by several hours | |||
| Tetracycline antibiotics - shell calcium can chelate the drug and lower bioavailability; stagger dosing | |||
| Levothyroxine - calcium-containing shell products may impair thyroid hormone absorption; separate by at least 4 hours | |||
| Iron supplements - concurrent calcium can reduce iron absorption; take at different times | |||
This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.