Research Shows That Cinnamon Affects Drug Metabolism

By Wayne Persky

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Most of us probably use cinnamon for various purposes, such as seasoning food, and some of us probably use it for its often promoted anti-inflammatory properties. However, Cassia cinnamon, the type most often found in stores selling supplements such as cinnamon capsules, contains high levels of coumarin, a natural blood thinner, which may because a bleeding risk (especially in patients on Plavix), and the products may interact with other anticoagulants or other medications commonly taken by older adults.

A recent online Medscape article discusses a new study led by researchers at the University of Mississippi that points out a potential concern for individuals taking prescription medications along with cinnamon supplements (University of Mississippi, 2025, April 24).1 The research, published in Food Chemistry: Molecular Sciences, found that cinnamaldehyde, the active compound in cinnamon, can alter drug metabolism by activating key liver and intestinal receptors and mildly inhibiting detoxification enzymes (Husain, et al., 2025).2

While cinnamon remains safe for nornal cooking uses, these findings are especially relevant to patients who have microscopic colitis (MC) or some other chronic inflammatory condition, and who manage their symptoms with multiple medications and supplements. For these patients, even seemingly benign supplements may interact with treatments, affecting efficacy and safety.
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The study showed that cinnamaldehyde, the major active compound in cinnamon, is fully available for absorption in the gut, and quickly converted to cinnamic acid in the liver, but not before it can activate xenobiotic receptors:

• PXR (pregnane X receptor)
• ​AhR (aryl hydrocarbon receptor)

These receptors regulate genes involved in drug metabolism, particularly CYP450 enzymes such as CYP2C9 and CYP1A2, which play a key role in breaking down many common medications. Cinnamon oil and cinnamaldehyde mildly inhibited these enzymes and moderately activated PXR and AhR in cell models.​

Why is this important for MC patients?

MC patients often rely on multiple medications and supplements, including:

• Budesonide (a corticosteroid that's metabolized by CYP3A4)
• Antidiarrheal agents
• Antidepressants or anti-anxiety medications
• Dietary supplements, such as vitamin D, curcumin, or magnesium
  

Because cinnamon compounds can influence how the body clears drugs, they might:
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• Reduce medication efficacy (by speeding up clearance)
• Increase side effects (by slowing breakdown)
• Alter the balance of other supplements and dietary choices that some individuals rely on for intestinal support

Cinnamon capsules are marketed for:

• Anti-inflammatory effects
• Blood sugar control
• ​Antioxidant benefits

​However, as noted in the opening paragraph of this article, Cassia cinnamon, the type most often found in stores and capsules, contains high levels of coumarin, a natural blood thinner, which may because a bleeding risk (especially in patients on Plavix), and they may interact with other other medications often taken by older adults

The bottom line appears to be:

While sprinkling cinnamon on food is safe, using cinnamon supplements without medical guidance, especially in patients with chronic diseases, could cause unwanted drug interactions. Until clinical studies better understand these effects in patients, especially those with GI disease, the safest course is caution.

References

1. University of Mississippi. (2025, April 24). Cinnamon could affect drug metabolism in the body. Medical Xpress, Retrieved from https://medicalxpress.com/news/2025-04-cinnamon-affect-drug-metabolism-body.html

2. Husain, I., Gurley, B. J., Kothapalli, H. B., Wang, Y-H., Vedova, L. D., Chittiboyina, A. G., . . . Khan, S. I. (2025). Evaluation of bioaccessibility, metabolic clearance and interaction with xenobiotic receptors (PXR and AhR) of cinnamaldehyde. Food Chemistry: Molecular Sciences, Retrieved from https://www.sciencedirect.com/science/article/pii/S2666566224000443