Cassia Twig — Safety & Interactions

Gui Zhi · Ramulus Cinnamomi

Contraindications

  • Warm or febrile disorders without cold involvement
  • Yin deficiency with Heat signs
  • Blood-heat bleeding or excessive sweating from fluid depletion

Cautions

  • Gui Zhi is lighter than Rou Gui but can still aggravate heat signs, thirst, restlessness, or bleeding if used in the wrong pattern
  • Some cinnamon products contain coumarin levels high enough to raise liver-safety concerns with excessive intake
  • 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

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.