Cassia Bark — Safety & Interactions

Rou Gui · Cortex Cinnamomi

Contraindications

  • Pregnancy
  • Yin deficiency with Fire signs
  • Excess internal Heat
  • Bleeding tendency or blood-heat hemorrhage

Cautions

  • Some cinnamon products contain enough coumarin to raise hepatotoxicity concerns, especially with prolonged or heavy intake
  • Medicinal Rou Gui doses are stronger than ordinary culinary cinnamon use and can aggravate heat signs, dry mouth, restlessness, or bleeding when misapplied
  • Gastrointestinal upset and allergic reactions have been reported with cinnamon products

Drug Interactions

Drug Class / Substrate Mechanism Severity Source
CYP450 substrate drugs Preclinical studies suggest cinnamon inhibits CYP2A6, CYP2C9, CYP2D, and CYP3A4 and may increase the risk of side effects from drugs metabolized by these enzymes Moderate Memorial Sloan Kettering Integrative Medicine - Cinnamon
Statins Concurrent use has been associated with hepatitis in a case report Moderate Memorial Sloan Kettering Integrative Medicine - Cinnamon
Pioglitazone Animal studies suggest cinnamon can increase pioglitazone bioavailability Moderate Memorial Sloan Kettering Integrative Medicine - Cinnamon

Pregnancy

Not recommended during pregnancy. Consult a qualified practitioner before any use.

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.