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The main difference in Ceylon vs cassia cinnamon is coumarin. Ceylon cinnamon (Cinnamomum verum) contains only traces of this natural flavoring compound, while cassia, the far more common type in North American stores, can contain enough that regular large amounts may exceed the safe intake limit European regulators set to protect the liver. Both taste like cinnamon and both have been studied for blood sugar, with mixed results. This guide compares the two, explains the coumarin limit, summarizes the research behind common cinnamon benefits claims, and covers the lead recalls and what to check on a cinnamon supplement label.
Peptide Labs sells several supplements that include cinnamon, but this article does not recommend any of them. It is general information, not medical advice.
Key Takeaways
- Ceylon cinnamon has only traces of coumarin; cassia averages about 0.3% coumarin by weight in German testing.
- Germany's BfR found a 60 kg adult reaches the coumarin safety limit with about 2 grams of cassia a day.
- Cassia is the usual supermarket cinnamon in North America unless the label says Ceylon.
- Meta-analyses on cinnamon for blood sugar disagree, and the trials are small, short and varied.
- Lead contamination is a separate problem: check FDA's ground cinnamon alert list.
Ceylon vs cassia cinnamon: the main differences
“Cinnamon” on a US label can mean any of four species. Ceylon, sometimes called true cinnamon, comes mainly from Sri Lanka. Cassia is a group of related trees grown in southern China and Southeast Asia: Chinese cassia (C. cassia, also listed as C. aromaticum), Indonesian cinnamon (C. burmannii) and Vietnamese or Saigon cinnamon (C. loureiroi). The NIH National Center for Complementary and Integrative Health (NCCIH) says cassia is the most common type sold in North America.
| Feature | Ceylon cinnamon | Cassia cinnamon |
|---|---|---|
| Botanical name | Cinnamomum verum (also C. zeylanicum) | C. cassia (C. aromaticum), C. burmannii, C. loureiroi |
| Main origin | Sri Lanka | Southern China, Indonesia, Vietnam |
| Coumarin | Traces only | About 0.3% on average, up to about 1% |
| In US stores | Less common; usually labeled Ceylon | The usual type when no species is named |
| Sticks | Many thin layers, like a cut cigar in cross-section | One thicker rolled layer |
| Color and flavor | Usually described as lighter and milder | Usually described as darker and stronger |
| Pregnancy note (NCCIH) | Larger amounts considered unsafe | Food amounts generally considered fine |
Ground powder is hard to tell apart by eye, according to Germany’s Federal Institute for Risk Assessment (BfR), so the label is your main clue. Sticks are easier: cassia forms one fairly thick roll, while a Ceylon stick is made of several fine, papery layers.
What is coumarin, and why does it matter?
Coumarin is a natural compound that smells of fresh hay. Used as a medicine in the past, it caused liver injury in a small group of sensitive people, from raised liver enzymes to hepatitis with jaundice in severe cases, usually reversing after it was stopped. Adding isolated coumarin to food is banned in the United States and the European Union, but coumarin that occurs naturally in cinnamon is not limited in the spice itself.
The European Food Safety Authority set a tolerable daily intake (TDI) of 0.1 milligram of coumarin per kilogram of body weight, an amount considered safe every day for life, and reconfirmed it in 2008. BfR, which uses the same value, calculated that a 60 kg adult reaches it with about 2 grams of cassia a day and a 15 kg child with about half a gram. BfR also says going slightly over for a week or two is not considered a risk; concern applies to large amounts of high-coumarin cassia over long periods. A 2010 BfR crossover study in 24 volunteers found coumarin from cassia powder was absorbed nearly as well as pure coumarin, so the limit applies to cinnamon in food too. These are safety limits, not targets.
Testing shows why species matters. A 2013 University of Mississippi study found authenticated Ceylon bark contained only traces of coumarin, while all three cassia species, especially Indonesian and Vietnamese, contained substantial amounts. Coumarin turned up in every store-bought cinnamon, cinnamon-flavored food and cinnamon supplement the team tested. A Czech survey of 60 ground cinnamon samples from 12 brands found none labeled with the species and all high in coumarin, while a Ceylon sample from a Sri Lankan plantation had none.
BfR says it is not aware of published cases of liver damage from eating cinnamon as food. Supplements are different: they can deliver concentrated cassia every day, and BfR warns that, depending on the label’s serving, cassia powder supplements may exceed the TDI. One 2015 case report described hepatitis in a 73-year-old woman who started cinnamon supplements while taking a statin; it resolved after both were stopped. A single case cannot prove cause, but it is a reason for caution.
Cinnamon benefits: what the research shows
NCCIH’s summary is blunt: research does not clearly support using cinnamon for any health condition, and it is unclear whether cinnamon supplements help with diabetes or weight loss. Most studies have looked at blood sugar.
Cinnamon for blood sugar
- Cochrane review, 2012. Ten randomized trials with 577 people with type 1 or type 2 diabetes, mostly using cassia for 4 to 16 weeks. The effect on fasting glucose was inconclusive, with no significant difference in HbA1c (a three-month glucose marker), insulin or after-meal glucose. Most trials had a high or unclear risk of bias, and the authors found insufficient evidence for use.
- Annals of Family Medicine, 2013. Ten trials with 543 people with type 2 diabetes found lower fasting glucose and blood fats but no significant change in HbA1c. Results varied widely between trials, and the authors said the right amount and duration were unclear.
- Phytotherapy Research, 2024. Pooling 24 trials in type 2 diabetes, researchers in Iran reported lower fasting glucose, insulin resistance scores and HbA1c, with no significant change in insulin levels.
- Nutrition Reviews, 2025. Twenty-eight trials with 3,054 adults with type 2 diabetes, lasting 30 to 120 days, showed lower fasting glucose, after-meal glucose and HbA1c, but heterogeneity between studies was very high (88% to 100% on the main measures).
Newer pooled analyses lean positive, while the older Cochrane review did not. The trials differ in cinnamon species, form and amount, most are small and short, and none measured long-term outcomes. Mayo Clinic’s view is that it is still not clear whether cinnamon lowers blood sugar in people with diabetes. A cinnamon supplement is not a replacement for diabetes care, and if you take medicines that lower blood sugar, talk to your prescriber before adding one rather than changing anything yourself.
Weight and cravings
Cinnamon appears in many metabolism and appetite blends, but NCCIH says its role in weight loss is unclear. Our guide on how to stop sugar cravings covers approaches with stronger evidence.
Lead in ground cinnamon: the recalls
Lead is a different issue from coumarin. In late 2023, WanaBana recalled apple cinnamon fruit puree pouches, later adding Schnucks and Weis store brands, after children were found with high blood lead. FDA confirmed 90 cases by January 31, 2024, received more than 200 adverse event reports, and traced the problem to economically motivated adulteration of cinnamon from Ecuador. On March 6, 2024, FDA warned consumers not to use certain ground cinnamon products with elevated lead, and it has expanded that alert several times since, most recently in October 2025, to nearly 20 products sold mainly through discount and specialty grocers. FDA advises discarding any listed product. The alerts name brands, not species, so Ceylon labeling alone does not answer the lead question.
Cinnamon supplement safety and interactions
- Liver. Mayo Clinic and NCCIH flag cinnamon supplements as a concern for people with liver disease. Memorial Sloan Kettering notes hepatitis reported with statins and lab signals of effects on drug-processing liver enzymes.
- Diabetes medicines. Because cinnamon is studied for blood sugar, combine it with glucose-lowering medicines only after checking with your prescriber.
- Stomach and allergy. Higher amounts or long use may cause digestive upset or allergic reactions; case reports link cinnamon-flavored products to mouth sores.
- Pregnancy and breastfeeding. NCCIH says food amounts appear safe in pregnancy, but larger amounts of Ceylon cinnamon are considered unsafe, and data in breastfeeding are limited.
- The cinnamon challenge. NCCIH warns never to swallow a spoonful of dry cinnamon powder; serious harm is possible.
How to read a cinnamon supplement label
Look for the species. “Ceylon cinnamon” or Cinnamomum verum tells you the coumarin source is low. “Cinnamon bark extract” or “cinnamon powder” with no species tells you very little, and BfR notes that coumarin in extracts also depends on how they are processed. Third-party testing for identity and heavy metals adds a check; see our guide to third-party tested supplements.
Three products we carry show the range. Plant People WonderBurn gummies list Cinnamomum verum bark extract with gynostemma, apple cider vinegar extract and chromium. ForestLeaf Berberine includes Ceylon cinnamon bark extract inside a botanical complex, with only the complex total given. The ColonBroom GLP-1 Premium Booster lists cinnamon bark extract without a species; the brand’s images describe it as a low-coumarin extract. All three are multi-ingredient formulas, so read about the other ingredients too, such as what berberine research shows and our chromium picolinate guide.
Frequently Asked Questions
Is Ceylon cinnamon healthier than cassia?
Ceylon has far less coumarin, which matters if you use a lot of cinnamon often or take a supplement daily. Germany’s BfR advises people who use large amounts in home cooking to choose Ceylon. Studies have not shown that either type offers greater health benefits.
Is the cinnamon in my kitchen Ceylon or cassia?
In North America it is most likely cassia unless the package says Ceylon or Cinnamomum verum. Sticks made of many thin layers are typically Ceylon.
How much coumarin is in cassia cinnamon?
German food monitoring found an average of about 0.3% by weight, with the highest samples near 1%. Ceylon contains only traces.
Does cinnamon lower blood sugar?
The evidence is mixed. Some meta-analyses report lower fasting glucose and HbA1c, while a Cochrane review found insufficient evidence. Trials are small, short and inconsistent, so the question remains open.
Can cinnamon supplements harm the liver?
High coumarin intake can affect the liver in sensitive people. Cassia-based supplements can exceed the European safety limit, so people with liver disease or who take statins should ask a clinician first.
Is ground cinnamon safe from lead?
FDA has listed nearly 20 ground cinnamon products with elevated lead since March 2024. Check FDA’s current alert and discard any listed product.
Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed September 2026.
Related guides: Berberine Benefits: What the Research Shows and What It Does Not, Chromium Picolinate Benefits: What the Evidence Shows for Blood Sugar and Weight, How to Stop Sugar Cravings: Why They Happen and What Research Supports, Gymnema Sylvestre: Benefits, Sweet Taste Research and Safety.