cinnamon sticks and ground cinnamon

How do you know when an herb, spice or supplement is safe? It makes sense to do some reading on anything you are planning to take before you begin swallowing it. Many people are taking cinnamon to control blood sugar or lower cholesterol. However, there are several different varieties of cinnamon. Consequently, it is reasonable to ask: is cinnamon toxic if you take it as a supplement?

Cinnamon and the Liver:

Q. Is cinnamon toxic to the liver? I ended up in the emergency room after taking 1,200 mg of cinnamon daily for several weeks. I’ll never do that again.

Know Your Cinnamon:

A. Cassia cinnamon, the type you normally find on the spice shelf in the supermarket, contains variable levels of coumarin (Woehrlin et al, Journal of Agricultural and Food Chemistry, Oct. 13, 2010). This compound can harm the liver (Abraham et al, Molecular Nutrition & Food Research, Feb. 2010).

To Avoid Toxicity, Stick with Water-Based Extracts:

Anyone who wants to use cinnamon to lower cholesterol or blood sugar would be well advised to stick with an aqueous extract because coumarin is not water-soluble. A person could purchase this in capsule form and avoid coumarin.

Is Ceylon Cinnamon Toxic?

Another option would be to use Ceylon cinnamon (Cinnamomum zeylonicum, true cinnamon or Cinnamomum verum). This is a different species that does not contain significant amounts of coumarin. It is more expensive, however.

There is some preliminary evidence that it too can help lower blood sugar and cholesterol (Costello et al, Journal of the Academy of Nutrition and Dietetics, Nov. 2016). An earlier review suggested that Ceylon cinnamon has antimicrobial activity and can lower blood sugar, cholesterol and blood pressure; it may be useful against stomach ulcers and seems to help protect the liver (Ranasinghe et al, BMC Complementary and Alternative Medicine, Oct. 22, 2017). There are too few clinical trials to be certain of these benefits, however.

In another study, researchers found high levels of E-cinnamaldehyde, an anti-inflammatory compound, in both C. zeylanicum and C. cassia (Gunawardena et al, Food & Function, March 2015).

What Should You Do?

People who include spices or dietary supplements in their regimen should monitor their progress with regular blood sugar tests. If you don’t know whether the cinnamon you are using is really Ceylon cinnamon, you should stick with the water extract or ask the doctor to monitor your liver enzymes regularly. In addition, it is not a good idea to combine cinnamon or any other supplement with medications unless a physician has investigated and approved the combination.

Was the dose too high? The research on cinnamon has used doses as high as 6 grams (6,000 mg). The 1,200 mg you were taking is in the same range as a dose being tested in a study currently being conducted, the CINNAMON trial (Cinnamon Trial-lIfestyle iNtervention Plus Water-soluble CiNnAMon Extract On loweriNg Blood Glucose in Pre-diabetics). We expect the results of this study should provide some answers about the safety and efficacy of cinnamon for lowering blood sugar.

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  1. Deb

    Wondering if Do Terra cinnamon bark oil is okay or if it causes liver problems

  2. Sara

    What about Saigon Cinnamon, the type I have on my shelf from Costco. Is it safe to use?

  3. Victoria

    What about water soluble extract of Cinnamomum burmannii?

  4. Barbara

    I have been taking fairly large amounts of Saigon Cinnamon. Does it have the same effects and cause the same concerns as Ceylon Cinnamon?

  5. Susan

    I switched to Ceylon cinnamon for the health properties, but the scent is not the same as cassia cinnamon. I added just a few dashes of regular cinnamon to the Ceylon cinnamon bottle to make it smell more like regular cinnamon. This seems to help…otherwise it just smells like a generic health food store kind of smell. Has anyone else noticed this? Or did I just buy a bad brand of Ceylon cinnamon? LOL. I ordered it from a reputable health food warehouse.

  6. HappyTraveler

    Some thoughts on the person ending up in the hospital after taking cinnamon, from a recently retired physician:
    1. Consider the source of the cinnamon.
    It may have had OTHER contaminants in it which a) caused the problem, or b) interacted with other melds/supplements you might have been taking.
    A good investment for me has been the online “Consumer Labs”, which tests various OTC supplements, foods, etc and then compares them with similar products (VERY MUCH as Consumer Reports does).

    2. Other meds could have competed for metabolism with the cinnamon that were ALSO metabolized by the liver (as the afore mentioned Coumarin-type meds). That could build up an excess of either the cinnamon OR the medication, resulting in your symptoms.

    3. You may have a enzyme deficiency that causes you to be a slow metabolized of the particular cinnamon product you used.
    If you have numerous medication intolerances, this should be considered. A good place to start is with, which has revealed such problems for several patients.
    If you have never had problems with meds before, and neither does anyone in your family, then I would not spend the money as it seems unlikely you have this problem.

    4. Some viruses OTHER than the familiar hepatitis viruses A, B, C, E do sometimes affect the liver. Did you have other symptoms that suggested a viral infection, such as sore throat, fever, aches & pains, malaise, GI symptoms? There are SO MANY virus possibilities that are not even testable, that would have been on my differential list in working up your presentation.

  7. Neil
    Pearl City, IL

    I drink a lot of tea and I used to put powdered cinnamon in each cup of tea. After reading (on this site) about coumarin not being water soluble, I started putting a cinnamon stick in each cup of tea. I still get the cinnamon flavor and not the coumarin.

  8. Pam
    S. Pasadena, Ca

    I use CInSulin a water extract of cinimon which i purchased from Costco. That has helped.

  9. Robyn

    It would be most helpful to have some more info on how to determine which type of cinnamon one has. I have Saigon cinnamon–which type is that?

    • Terry Graedon

      Saigon cinnamon is a type of Chinese or cassia cinnamon.

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