Cinnamon Supplements May Reduce Effectiveness of Medications, Study Finds

Epoch Times

13-05-2025

That sprinkle of cinnamon in your coffee or oatmeal? Probably harmless. But taken as a supplement, it could change how your body processes prescription drugs, new research suggests.
Cinnamaldehyde, the compound behind cinnamon's signature flavor and scent, can interfere with how the body processes medications. The recent study on human liver and gut cells found that at high concentrations, the compound may speed up drug metabolism, clearing medications before they can take full effect.
'Cinnamaldehyde has a low to moderate potential for drug interactions based upon our preliminary in vitro studies,' co-author of the study Bill Gurley, who is a principal scientist at the National Center for Natural Products Research, told The Epoch Times in an email.
What Researchers Discovered
In a
At concentrations above 270 micrograms per milliliter, which would be reached only through taking high-dose supplements, cinnamaldehyde activated these receptors, acting like gatekeepers, telling the body how quickly to break down and eliminate medications.
Researchers say that this could be a concern for people taking certain medications—particularly drugs metabolized by the liver enzymes CYP2C9 and CYP1A2, such as some blood thinners, diabetes drugs, antidepressants, and anti-inflammatory drugs.
'Cinnamon and cinnamon-based supplements are quite safe when used in moderation,' Gurley said. 'The likelihood that cinnamaldehyde poses any risk for clinically relevant drug interactions is quite low.'
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The researchers found no changes in PXR activity at lower levels of cinnamaldehyde (up to 20 micrograms per milliliter), suggesting that everyday use—like those typically used in cooking—is unlikely to be a problem.
Even in a
'It is okay to consume cinnamon in food or take it as a supplement in moderation,' Shabana Khan, a principal scientist at the university's National Center for Natural Products Research and co-author of the study, told The Epoch Times in an email. Health concerns, however, can arise when supplements are used in high doses or for long periods—especially without a doctor's knowledge.
Some people take
'It's difficult to define how much is too much since different preparations or products / supplements will have different quantities or vary in composition,' she said. 'It should be used in moderation.'
Know Your Cinnamon
Cinnamon is used in several forms, each with varying levels of risk.
Ground cinnamon, the kind you likely have in your spice rack, is used in cooking and baking, and up to a teaspoon is considered safe. Cinnamon oil, often used in foods and personal care products, poses little risk in small amounts. However, supplements, which can contain anywhere from 500 to 1,000 milligrams per dose, can be more concentrated and potentially interfere with medications when taken regularly.
Most cinnamon sold in U.S. stores is
Labels don't always list the type of cinnamon used; unless otherwise stated, it's mostly like going to be cassia. You can also contact the manufacturer for clarification, especially if you are taking cinnamon in supplement form.
Apart from cinnamaldehyde, cinnamon also contains coumarin, a naturally occurring blood thinner.
'Cassia cinnamon, often sourced from regions like Southern China, contains significantly higher levels of coumarin and is a potent blood thinner compared to true cinnamon (Cinnamomum verum) from Sri Lanka,' study co-author Amar Chittiboyina, associate director at the National Center for Natural Products Research, told The Epoch Times in an email.
True cinnamon or
'We strongly advise individuals currently taking blood thinners who are considering incorporating cinnamon into their daily routine to consult with their primary healthcare physician,' Chittiboyina said.
Still, researchers say that when used appropriately, cinnamon may offer benefits. A 2022 scientific
But as with many natural compounds, the benefits may depend on the dose, the form, and how it's used.
Other Competing Foods and Herbs
Cinnamon isn't the only natural ingredient that can interact with medications. Common foods and herbs can affect how drugs are absorbed or broken down—something to keep in mind if you take medication regularly.
For example, grapefruit can block
like warfarin. Dairy products can reduce the absorption of some antibiotics, making them less effective.
Several herbs and supplements have also been linked to well-documented drug interactions, according to Gurley. St. John's Wort, often used for mild depression, can reduce the effectiveness of medications like antidepressants, birth control pills, and antivirals by speeding up liver enzyme activity.
Goldenseal may slow down drug metabolism of certain statins, antihistamines, and sedatives, increasing drug levels in the body. And licorice root—unless it's had the glycyrrhizin compound removed—can raise blood pressure and interfere with blood pressure medications.
'Our best advice is to talk to a health care provider before using any supplements along with prescription medicine,' Khan said.