Camilla Jessen
A new study suggests that cinnamon supplements may interfere with how the body processes certain medications, potentially reducing their effectiveness.
Cinnamon is often praised for its health benefits—from lowering blood sugar to adding sweetness without sugar.
But new research suggests that in supplement form, it may interfere with how the body absorbs and processes certain medications.
A study published in Food Chemistry: Molecular Sciences by researchers at the University of Mississippi found that cinnamaldehyde, a compound in cinnamon, may interact with the body’s xenobiotic receptors—proteins that detect foreign substances such as drugs.
How the Study Was Conducted
To simulate the human digestive process, researchers recreated intestinal environments in the lab using stomach acid, enzymes, and intestinal and liver cells.
They tested how various cinnamon components—including cinnamon oil, cinnamic acid, and cinnamaldehyde—were absorbed in both fasted and fed conditions.
The results showed that cinnamaldehyde moderately activated xenobiotic receptors, which could potentially cause the body to eliminate medications more quickly than intended.
“Overconsumption of [cinnamon] supplements could lead to a rapid clearance of prescription medicine from the body, and that could result in making the medicine less effective,” said co-author Shabana Khan, Ph.D., in a press statement.
The study was conducted in laboratory settings—not on humans—so its findings are preliminary.
“We know there’s a potential for cinnamaldehyde to activate these receptors that can pose a risk for drug interactions,” said co-author Bill Gurley, Ph.D. “But we won’t know exactly what will happen until we do a clinical study.”
Cassia vs. Ceylon: What Consumers Should Know
Most cinnamon sold in the U.S. is cassia cinnamon, a cheaper, more pungent variety from Asia. It contains higher levels of coumarin, a natural compound that can act as a blood thinner.
Ceylon cinnamon, also known as “true cinnamon,” contains much less coumarin and is generally considered safer for regular use.
Health experts advise caution, particularly for individuals taking blood thinners like warfarin (Coumadin), apixaban (Eliquis), clopidogrel (Plavix), or aspirin.
Frequent use of cassia cinnamon in large amounts or as a supplement could potentially interact with these medications.
Recommendations for At-Risk Groups
People with chronic health conditions such as high blood pressure, diabetes, cancer, arthritis, asthma, HIV, or depression should consult their healthcare providers before using cinnamon supplements or consuming large amounts of cassia cinnamon.
“You don’t need to completely avoid cinnamon if you’re on medication,” said Jessica Ball, M.S., RD, senior nutrition editor at EatingWell. “But this is a good reminder to be cautious with supplements and stick to moderate amounts of spices in food.”
The U.S. Food and Drug Administration does not require labeling to distinguish between cassia and Ceylon cinnamon. If a label doesn’t specify Ceylon, it is likely cassia.
Consumers are advised to limit cassia cinnamon intake to under one teaspoon per day if used regularly.
Experts also warn that some commercial cinnamon products may be mixed with fillers or anti-caking agents.