Calcined Ark Shell — Safety & Interactions

Duan Wa Leng Zi · Concha Arcae Praeparata

Contraindications

  • Spleen-Stomach deficiency-cold with weak digestion but no acid regurgitation or heat irritation
  • Routine long-term use when low stomach acid rather than hyperacidity is the real problem

Cautions

  • Like other calcium-rich shell medicines, Duan Wa Leng Zi can interfere with the absorption of certain medications when taken at the same time
  • Only properly cleaned and medicinally calcined shell should be used; shell products from uncertain sourcing may carry contamination or microbial residue risk
  • The processed powder is aimed at excess acidity and ulcer irritation, not at indiscriminate long-course supplementation
  • MSK page not found - drug interaction data not available from Memorial Sloan Kettering integrative medicine database

Drug Interactions

Drug Class / Substrate Mechanism Severity Source
Fluoroquinolone antibiotics (ciprofloxacin, levofloxacin) - calcium-rich shell minerals can chelate the drug and reduce absorption; separate by several hours
Tetracycline antibiotics - calcium binding can reduce antibiotic bioavailability; stagger dosing
Levothyroxine - calcium-containing minerals 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.