Cinnamon has earned a reputation as a health booster. But the researchers behind a new study warn that high doses of the spice, specifically in the form of dietary supplements, may decrease the effectiveness of certain prescription drugs.
“Overconsumption of supplements could lead to a rapid clearance of the prescription medicine from the body, and that could result in making the medicine less effective,” said study author Shabana Khan, PhD, a principal scientist at the National Center for Natural Products Research at the University of Mississippi, in a statement. “Health concerns could arise if excessive amounts of supplements are consumed without the knowledge of a healthcare provider or prescriber of the medications.”
In the research, which was published in the June edition of Food Chemistry: Molecular Sciences, Dr. Khan and her collaborators found that cinnamaldehyde, a compound responsible for cinnamon’s distinctive taste and smell, activates receptors in the body that speed up how quickly medications are metabolized, potentially flushing them out before they have time to work.
Cassia cinnamon bark from southern China poses additional risk, Khan and her team say. In addition to containing cinnamaldehyde, this type of cinnamon has high levels of coumarin, a compound also present in fenugreek seeds that has anticoagulant properties, making it dangerous for people on blood thinners. Coumarin is also known to cause liver damage in large doses.
Which Drugs Can Cinnamon Supplements Interact With?
Cinnamon supplements may be of particular concern for people who take medications processed by the liver, like those for diabetes, blood pressure, and mood disorders, according to Wesley McWhorter, DrPH, spokesperson for the Academy of Nutrition and Dietetics.
Khan counsels patients to be extra cautious with cinnamon supplements if they have a chronic illness, such as hypertension, diabetes, cancer, arthritis, asthma, obesity, HIV, AIDS, or depression.
While this study confirms earlier research on cinnamon’s interactions with medications, Khan and her colleagues concluded that more research is needed, including clinical trials in humans, to fully understand the role that cinnamon plays in the body and what potential spice-drug interactions may occur.
Cinnamon Sprinkled on Your Latte Is Not a Concern
Dr. McWhorter stresses that the amount of cinnamon you sprinkle on a latte or add to a recipe doesn’t pose the same risk as supplements, which deliver a much higher dose of active compounds.
“Enjoy cinnamon in your diet, but be cautious about supplementing — and always talk to a registered dietitian or healthcare provider before adding it to your regimen,” says McWhorter, who was not involved in the study.
Flavoring foods and beverages with modest amounts of cinnamon may indeed have potential health benefits, according to Christine Ryan, RDN, a registered dietitian-nutritionist in Seattle. These include lowering blood glucose levels, lowering cholesterol, and fighting inflammation and infection.
“Using cinnamon as a spice in food is the safest way,” says Ryan, who was not involved in the research. “Cinnamon paired with a whole-food, plant-based diet is the best practice to use cinnamon without overdoing it. Ground cinnamon can be added to oatmeal, baked goods, applesauce, or coffee. Cinnamon sticks can be added to stews or sauces or simmered with beans and lentils.”
EDITORIAL SOURCES
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Husain I et al. Evaluation of bioaccessibility, metabolic clearance and interaction with xenobiotic receptors (PXR and AhR) of cinnamaldehyde. Food Chemistry: Molecular Sciences. June 2025.
Espiritu M et al. Mechanisms of Herb-Drug Interactions Involving Cinnamon and CYP2A6: Focus on Time-Dependent Inhibition by Cinnamaldehyde and 2-Methoxycinnamaldehyde. Drug Metabolism and Disposition. October 2020.
Qin B et al. Cinnamon: Potential Role in the Prevention of Insulin Resistance, Metabolic Syndrome, and Type 2 Diabetes. Journal of Diabetes Science and Technology. May 1, 2010.
Das G et al. Cardiovascular protective effect of cinnamon and its major bioactive constituents: An update. Journal of Functional Foods. October 2022.
Tom Gavin joined Everyday Health as copy chief in 2022 after a lengthy stint as a freelance copy editor. He has a bachelor's degree in psychology from College of the Holy Cross.
Prior to working for Everyday Health, he wrote, edited, copyedited, and fact-checked for books, magazines, and digital content covering a range of topics, including women's health, lifestyle, recipes, restaurant reviews, travel, and more. His clients have included Frommer's, Time-Life, and Google, among others.
He lives in Brooklyn, New York, where he likes to spend his time making music, fixing too-old electronics, and having fun with his family and the dog who has taken up residence in their home.
Don Rauf has been a freelance health writer for over 12 years and his writing has been featured in HealthDay, CBS News, WebMD, U.S. News & World Report, Mental Floss, United Press International (UPI), Health, and MedicineNet. He was previously a reporter for DailyRx.com where he covered stories related to cardiology, diabetes, lung cancer, prostate cancer, erectile dysfunction, menopause, and allergies. He has interviewed doctors and pharmaceutical representatives in the U.S. and abroad.
He is a prolific writer and has written more than 50 books, including Lost America: Vanished Civilizations, Abandoned Towns, and Roadside Attractions. Rauf lives in Seattle, Washington.
