Coumarin content in cinnamon – what’s the deal?

Some of my astute, concerned clients have asked me about the reported coumarin content in cinnamon, so I thought I’d set the record straight here.

Coumarin is a natural blood thinner from which the drug, Warfarin (generic: coumadin), is derived. Blood thinners are useful in preventing blood clots which prevent heart attacks and strokes, but too much of a good thing runs the risk of excess bleeding. What does this all have to do with cinnamon, you ask?

cinnamon sticksTypes of Cinnamon

There are several species of cinnamon on the commercial, American market:  Cinnamomum cassia, C. verum, C. burmannii just to name a few.  Trade laws allow for any of these species to be sold simply as ‘cinnamon’.  Therefore, it’s possible that when you buy a jar of cinnamon in the grocery store, you don’t know which species you are getting.  This fact is important because it turns out that only certain species contain notable amounts of coumarin.

Coumarin content in cinnamon

One of the more common types of cinnamon sold in the United States is cassia cinnamon (C. cassia), quite frankly because it’s a lesser quality than what is known as Ceylon or “true” cinnamon (C. verum, where ‘verum’ is Latin for roughly ‘true’). Unfortunately, cassia contains the highest amounts of coumarin of all the species. But before you rush to your spice cabinet and throw away all your cinnamon stash, read on because it’s not as bad as it sounds…

According to the Natural Medicines database, the amount of coumarin in cassia cinnamon can be up to 1.2%, which translates to about 6-12mg in one teaspoon (2020). In 2010, Abraham, et al., determined that a tolerable daily intake (TDI) of coumarin was up to 0.05mg/lb of body weight. The TDI was based on the potential of liver toxicity and not the cardiovascular effects discussed above.

This amount translates to about 6.8mg for a 150 lb person – right at the lower end of the TDI. But remember, that’s the amount in a whole teaspoon of cassia. How many of us are eating that much in one shot? Probably not too many – most of the culinary recipes I have contain 1 teaspoon for the whole recipe. So, fear not when you’re enjoying your cinnamon raisin muffins or chai tea as you should be just fine for normal, culinary use.

cinnamon chai tea

What if you are taking cinnamon in higher doses for medicinal use? (See my recent Ask the Herbalists’ post for some good scoop on cinnamon and blood sugar regulation). If you are at risk for liver damage or have cardiovascular complications, you may want to discuss what a healthy dose of cinnamon might be for your particular circumstances. Or, there’s another option…

Enter Ceylon “True” Cinnamon

Remember I said there were multiple species of cinnamon?  It turns out that true cinnamon (C. verum) has far less coumarin than its lesser-quality sister, cassia.  Back to the Natural Medicines database, which indicates that true cinnamon contains only about 0.004% coumarin – a trace amount (2020).  It might be more expensive, but it also has a more subtle, sweet taste that’s particularly good for baking and tea.

Where can I find Ceylon cinnamon?

Likely not in the grocery store.  As I mentioned, most of the mainstream commercial products are cassia cinnamon, and it’s possible that the product won’t specify the type.  You might get lucky and find Ceylon cinnamon in a health-food store or in the natural section of a grocery store.  But your best bet is to find a reputable spice business, preferably that sources ethically and keeps a fresh inventory.

Ceylon cinnamon

I recently discovered Cinnamon Tree Organics, which sells a high quality Ceylon cinnamon direct from Sri Lanka (the ‘new’ name of Ceylon).  Their website indicates that they buy cinnamon sticks direct from the grower and grind and mill them on demand.  Keeping the bark whole until it’s needed keeps the aromatic oils fresh, ensuring the strongest, most flavorful result.

Final Thoughts

I hope this clears up some of the mystery of coumarin content in cinnamon and provides useful information for how to use cinnamon safely.  As always, feel free to contact me with any questions or for assistance in any health-related challenges you might have.  I love hearing from you! In the meantime…

What are you waiting for?  Cinnamon and fall are perfect for one another!


Abraham, K. Wohrlin, F., Lindtner, O., Heinemeyer, G., Lampen, A. (2010). Toxicology and risk assessment of coumarin: focus on human data. Molecular Nutrition and Food Research. 54(2). 228-39. doi: 10.1002/mnfr.200900281.

Natural Medicines (2020).  Cassia cinnamon monograph.  Retrieved from:

Natural Medicines (2020).  Ceylon cinnamon monograph.  Retrieved from:

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