Cinnamon Oil — Safety & Interactions
Gui Pi You · Oleum Corticis Cinnamomi
Use with caution. Practitioner review recommended before use.
Contraindications
- Known cinnamon or cassia hypersensitivity
- Undiluted application to damaged skin or mucous membranes
- Marked internal heat or Yin-deficiency heat patterns
Cautions
- Cinnamon oil is more irritating and sensitizing than the crude bark herb and should generally be diluted before topical use.
- Some cinnamon products contain enough coumarin to raise hepatotoxicity concerns, especially with heavy or prolonged intake.
- Gastrointestinal burning, mucosal irritation, and allergic skin reactions are possible with concentrated cinnamon oils.
Drug Interactions
| Drug Class / Substrate | Mechanism | Severity | Source |
|---|---|---|---|
| CYP450 substrate drugs | Preclinical cinnamon literature suggests enzyme inhibition that could alter exposure to some CYP-metabolized drugs when concentrated preparations are used heavily. | Moderate | Cinnamon pharmacology and integrative-medicine summaries |
| Hepatotoxic drugs | Coumarin-bearing cinnamon products may add to liver burden in susceptible patients or with prolonged high exposure. | Moderate | Cassia cinnamon toxicology literature |
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.