Cinnamon as a Food: Cassia vs Ceylon and Coumarin
Cassia and Ceylon cinnamon as foods, why coumarin in cassia matters for heavy users, the European tolerable daily intake as reported by German scientists, and blood sugar research.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Two cautions first. Never swallow a spoonful of dry cinnamon powder as a dare; NCCIH calls the "cinnamon challenge" an unsafe internet dare where serious harm is possible. [1] Second, cassia cinnamon contains coumarin, a compound linked to liver effects in some people, and the amount varies widely from one product to another. [1] [2]
Which cinnamon is it?
Cinnamon is a spice from the dried bark of several species of Cinnamomum. [1] "True" or Ceylon cinnamon, Cinnamomum verum J.Presl (Lauraceae), grows mainly in Sri Lanka. [1] [3] Cassia cinnamon comes from southeastern Asia and is the most common type sold in North America. [1] NCCIH names cassia as Cinnamomum aromaticum (also known as Cinnamomum cassia), which matches the accepted name in the GBIF backbone, Cinnamomum aromaticum Nees. [1] [4] NCCIH notes that products may not say which species or plant part was used. [1] Herb-level detail is on Ceylon vs cassia cinnamon and Cinnamon.Coumarin: cassia and Ceylon compared
| Question | What the sources found |
|---|---|
| Coumarin in cassia | Some cassia products contain high levels; scientists at Germany's Federal Institute for Risk Assessment (BfR) described up to 1% coumarin in cassia. [1] [5] |
| Coumarin in Ceylon | NCCIH says Ceylon cinnamon may contain a trace amount. [1] |
| How much it varies | In a 2010 BfR study of German retail cinnamon, stick samples from two packages ranged from below the detection limit to about 10,000 mg/kg, and levels varied even within one tree. [2] |
| Official limit | The European Food Safety Authority (EFSA) set a tolerable daily intake (TDI) for coumarin in 2004, reported as 0.1 mg per kg of body weight, based on animal liver data. [6] |
| Heavy users | Heavy consumers of cassia cinnamon may reach a daily coumarin intake corresponding to the TDI. [6] |
| Cinnamon in meals | In a crossover study of 24 volunteers, absorption of coumarin from cinnamon powder, tea and rice pudding was only slightly lower than from isolated coumarin, so the TDI can be used for meals containing cinnamon. [5] |
We read the TDI as reported in BfR-authored research papers, not on EFSA's own page. Coumarin can cause liver effects in a proportion of people, and the cause of that higher sensitivity is unknown. [6] NCCIH says cassia usually does not supply enough to cause significant problems, but long use could be an issue for sensitive people such as those with liver disease. [1] The sources we read do not give an everyday safe number of teaspoons, and this page does not either.
Traditional use
The bark, leaves, flowers, fruits and roots of cinnamon have a long history in traditional medicine and cuisine in China, India and Persia (Iran), and it was thought to help inflammation, nerve pain, heart disease and cough. [1] This is traditional use only.What research shows
| Use | What the source found | Strength of evidence | Form studied |
|---|---|---|---|
| Blood sugar in type 2 diabetes | A 2025 meta-analysis of 28 trials (3,054 people, 30 to 120 days) found lower fasting glucose, but results varied a great deal between trials (I2 = 88%). [7] A 2024 analysis of 24 trials also reported lower fasting blood sugar. [8] NCCIH says it is unclear whether cinnamon helps diabetes, and that studies often do not say which species or part was tested. [1] | Mixed | Cinnamon supplementation, mostly capsules; species often unclear |
| Weight | NCCIH says it is unclear whether cinnamon supplementation helps with weight loss. [1] | Insufficient evidence | Supplements |
| Cinnamon sprinkled on food, any health outcome | Proper evidence not found. We looked in NCCIH and PubMed meta-analyses; they tested supplements. | Not assessable | Food amounts |
NCCIH's summary is that research does not clearly support cinnamon for any health condition. [1] See also Foods and blood sugar.
Related
Cinnamon tea, Foods and blood sugar and Fiber and whole grain claims on packages.Frequently asked questions
Is Ceylon cinnamon safer than cassia?
NCCIH says Ceylon may contain only a trace of coumarin, while some cassia products are high. [1] The sources we read do not compare overall safety beyond coumarin.
What is the coumarin limit?
EFSA's 2004 tolerable daily intake is reported as 0.1 mg per kg of body weight per day. [6] It is a long-term guide for the whole day, not an amount to aim for.
Does cinnamon lower blood sugar?
Meta-analyses of supplement trials found lower fasting glucose but with large differences between trials. [7] NCCIH says it is unclear. [1]
Can the label tell me which cinnamon I have?
Not always; NCCIH says products may not clearly indicate the species or part used. [1]
Is it safe in pregnancy?
Food amounts appear safe in some studies; larger amounts of Ceylon cinnamon are considered unsafe. [1] Ask your prenatal clinician.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and individual considerations
- Liver disease. See the coumarin note above; ask a clinician about cassia if you have liver disease. [1]
- Medicines. NCCIH says there are theoretical reasons to suspect some cinnamon components may interact with an anticancer medicine or nicotine, and advises asking a provider about any medicine. [1] Ask a pharmacist; see How interactions work. Diabetes medicines are not discussed in the sources we read, so ask if you take them.
- Pregnancy and breastfeeding. Some studies suggest cinnamon in food amounts is safe in pregnancy, while larger amounts of Ceylon cinnamon are considered unsafe; little is known for breastfeeding. [1]
- Allergy and skin. Cinnamon can cause gastrointestinal problems or allergic reactions when used in larger amounts or for long periods. [1]
- Oil is not food. For cinnamon oil see Cinnamon oil.
References
- National Center for Complementary and Integrative Health (NCCIH). Cinnamon. Read 2026-10-23.
- Quantification of flavoring constituents in cinnamon: high variation of coumarin in cassia bark from the German retail market and in authentic samples from Indonesia. J Agric Food Chem 2010. PMID 20853872. Read 2026-10-23.
- GBIF Secretariat. Cinnamomum verum J.Presl, GBIF Backbone Taxonomy. Read 2026-10-23.
- GBIF Secretariat. Cinnamomum aromaticum Nees, GBIF Backbone Taxonomy. Read 2026-10-23.
- Relative bioavailability of coumarin from cinnamon and cinnamon-containing foods compared to isolated coumarin: a four-way crossover study in human volunteers. Mol Nutr Food Res 2011. PMID 21462332. Read 2026-10-23.
- Toxicology and risk assessment of coumarin: focus on human data. Mol Nutr Food Res 2010. PMID 20024932. Read 2026-10-23.
- Effects of cinnamon supplementation on metabolic biomarkers in individuals with type 2 diabetes: a systematic review and meta-analysis. Nutr Rev 2025. PMID 38917435. Read 2026-10-23.
- The effect of cinnamon supplementation on glycemic control in patients with type 2 diabetes mellitus: An updated systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res 2024. PMID 37818728. Read 2026-10-23.