How much cinnamon do you have to eat for it to be toxic?

October 28, 2025 •

5 min read

Cinnamon contains a natural compound called coumarin, which can cause liver damage in sensitive individuals if consumed in large quantities over a prolonged period. Understanding how much cinnamon do you have to eat for it to be toxic requires distinguishing between the two main types and considering individual health factors.

Quick Summary

The toxicity of cinnamon largely depends on the type, with Cassia containing high coumarin levels that can harm the liver in excess. Ceylon cinnamon has much less coumarin, making it safer. Limiting Cassia intake to about one teaspoon daily is a sensible precaution.

Key Points

Cassia vs. Ceylon: Cassia cinnamon, the most common type, is high in coumarin and poses a liver toxicity risk, while Ceylon cinnamon has negligible amounts and is much safer for frequent consumption.
Daily Limit for Cassia: For healthy adults, it is wise to limit daily intake of Cassia cinnamon to approximately half a teaspoon (2 grams) to stay within the safe coumarin limits.
Coumarin is the Culprit: The primary toxic agent in cinnamon is coumarin, which can cause liver damage when consumed in high doses over prolonged periods.
Vulnerable Groups: Children, individuals with liver disease, pregnant or breastfeeding women, and those on specific medications (e.g., blood thinners) are at higher risk and should limit Cassia cinnamon intake.
Beyond Coumarin: Excessive cinnamon intake can also cause mouth sores, digestive upset, allergic reactions, and dangerously low blood sugar levels, especially for those with diabetes.
Check Labels: To avoid high coumarin, look for Ceylon cinnamon (Cinnamomum verum) on product labels, especially for supplements or if you are a frequent user.

The Toxic Culprit: Coumarin

At the heart of cinnamon's potential for toxicity is a naturally occurring compound called coumarin. This chemical is responsible for the spice's risk to human health when consumed in high doses over time. The key factor is that coumarin can be hepatotoxic, meaning it can cause damage to the liver. The risk depends almost entirely on the type of cinnamon you are consuming.

Cassia vs. Ceylon: A Critical Distinction

There are two main types of cinnamon widely available: Cassia and Ceylon. The difference in their coumarin content is significant and defines their safety profile for regular, high-volume consumption.

Cassia Cinnamon: This is the most common and affordable type sold in grocery stores in North America. It comes from the Cinnamomum cassia tree and contains a high amount of coumarin, ranging from 0.1 to 3.5 milligrams per gram.
Ceylon Cinnamon: Often called "true" cinnamon, this variety comes from the Cinnamomum verum tree, native to Sri Lanka. Ceylon cinnamon contains only trace amounts of coumarin, making it significantly safer for long-term or high-dose use.

How Much Coumarin Is Safe?

Regulatory bodies have established a Tolerable Daily Intake (TDI) for coumarin to minimize the risk of liver damage. This figure is set at 0.1 mg of coumarin per kilogram of body weight per day. To put this into perspective, let's look at what this means for Cassia cinnamon, the type with high coumarin content. The coumarin level can vary widely in Cassia, which is why sticking to conservative estimates is important.

For a 60 kg (132 lb) adult, the TDI is 6 mg of coumarin per day. If a sample of Cassia cinnamon contains 2.5 mg of coumarin per gram (a common average), then consuming just over two grams, or roughly a teaspoon, of this cinnamon would reach the daily limit.

Consider this breakdown:

Conservative daily limit for Cassia: About half a teaspoon (2 grams) per day for a 60 kg adult.
Risk of liver damage: Regular, daily consumption of more than 6 grams (approximately 1.5 teaspoons) of Cassia cinnamon is considered possibly unsafe for a long period.
For children: Small children are particularly vulnerable due to their lower body weight. A study found that consuming just 0.5 grams of Cassia cinnamon could reach a small child's TDI for coumarin.

Potential Health Risks and Symptoms

Beyond chronic liver damage from coumarin, excessive intake of cinnamon can cause other health issues, especially when consumed in large, concentrated amounts, such as with supplements or the "cinnamon challenge".

Oral Irritation: The cinnamaldehyde in cinnamon can cause inflammation, irritation, and sores in the mouth and on the lips with heavy use.
Low Blood Sugar: While cinnamon can help regulate blood sugar, an overconsumption can cause blood glucose levels to drop too low, especially for those on diabetes medication.
Digestive Issues: Large doses can irritate the gastrointestinal tract, leading to stomach upset, nausea, or diarrhea.
Allergic Reactions: Some individuals may experience allergic reactions, including skin rashes, swelling, or difficulty breathing.
Blood Thinning: High doses of cinnamon can have an anticoagulant effect, posing a risk for those on blood-thinning medications.

Cassia vs. Ceylon Cinnamon Comparison


Feature	Cassia Cinnamon	Ceylon Cinnamon	Health Implications
Coumarin Content	High	Trace amounts	High coumarin increases the risk of liver damage with regular, high intake.
Availability	Common in most grocery stores	Sold at specialty spice shops; rarer	Cassia is cheaper and more widely used in commercial food products.
Flavor	Strong, spicy, pungent	Subtle, sweet, and mild	Cassia is ideal for robust, bold flavors, while Ceylon is better for delicate dishes.
Appearance	Thick, single-layer sticks; reddish-brown	Thin, multi-layered, and brittle quills; lighter tan color	Ceylon's visual cues help distinguish it from Cassia.
Price	Affordable	More expensive	Ceylon's higher price reflects its scarcity and labor-intensive production.

Conclusion

The amount of cinnamon you have to eat for it to be toxic depends significantly on the type. For the Cassia variety common in grocery stores, regular consumption exceeding about a teaspoon per day poses a risk of liver damage due to its high coumarin content. A small child's toxic threshold is even lower. However, Ceylon, or "true" cinnamon, contains only trace amounts of coumarin and is the safer choice for those who use cinnamon frequently or in larger doses. For most people, consuming cinnamon as a common food spice in moderation is safe. However, individuals with pre-existing liver conditions, those on specific medications, and parents of young children should be cautious with Cassia cinnamon intake and consider switching to the low-coumarin Ceylon variety for regular use. Always consult a healthcare provider before starting high-dose cinnamon supplementation. For more information on the side effects of cinnamon, see this useful resource: Healthline on Cinnamon Side Effects.

What to Do for Safe Cinnamon Consumption

Limit Your Intake of Cassia Cinnamon

For most healthy adults, keeping Cassia cinnamon intake under a single teaspoon per day is a safe guideline. This is especially important for long-term daily use. Moderation is the key to enjoying its flavor without risk.

Switch to Ceylon Cinnamon

If you use cinnamon regularly, for example in daily smoothies, oatmeal, or as a supplement, opting for Ceylon cinnamon is the safest choice due to its minimal coumarin content. While more expensive, it eliminates the liver toxicity risk associated with Cassia.

Check Product Labels

When buying ground cinnamon or supplements, look for the botanical name on the label. Cinnamomum verum indicates Ceylon, while Cinnamomum cassia or simply "cinnamon" usually signifies the high-coumarin Cassia type.

Be Mindful of Supplements

Cinnamon supplements often contain highly concentrated extracts of Cassia cinnamon, making it easy to exceed the coumarin TDI. This is particularly risky for those with underlying health conditions. Always consult a doctor before starting supplements.

Consider Vulnerable Populations

Children, pregnant women, and people with liver disease or diabetes should be especially cautious. For these groups, even modest amounts of high-coumarin Cassia could pose a health risk.

Monitor for Symptoms

Pay attention to symptoms of liver stress, such as nausea, abdominal discomfort, fatigue, or jaundice, and consult a doctor if they appear after increasing cinnamon consumption.

When Is It Safe to Consume More?

It is important to remember that occasional, moderate use of Cassia cinnamon is unlikely to cause any harm for most healthy people. The primary concern is chronic, daily consumption of large doses, such as those found in supplements or extreme culinary uses. The risks are dose-dependent, and the occasional cinnamon roll or sprinkle on oatmeal is well within safe limits.

Frequently Asked Questions

A single, large dose of cinnamon is unlikely to cause permanent damage for a healthy person, though it can cause oral irritation, stomach upset, or low blood sugar. The primary concern for liver toxicity is related to chronic, high-dose consumption.

Cassia cinnamon sticks are thick, tough, and reddish-brown, while Ceylon sticks are thin, brittle, and light tan with multiple layers. Ground cinnamon is harder to differentiate visually, so checking the product label for the botanical name is the most reliable method.

Yes, excessive cinnamon intake can interact with certain medications, particularly blood thinners, drugs for liver disease, and diabetes medications, by potentially intensifying their effects. Always consult a healthcare provider if you take these medications.

The most serious toxicity is liver damage, which can manifest as fatigue, nausea, abdominal discomfort, itching, dark urine, and jaundice. If you experience these symptoms after high, prolonged cinnamon intake, seek medical advice.

Small children have a much lower coumarin tolerance due to their body weight. Moderate amounts of Cassia cinnamon used in occasional baking are likely fine, but daily, high-volume consumption is not recommended. Opting for Ceylon cinnamon is a safer alternative.

Yes, the "cinnamon challenge," which involves inhaling a tablespoon of cinnamon powder, is extremely dangerous. It can cause serious lung damage and respiratory problems, as the powder is difficult to process and can cause a choking hazard.

Cooking does not significantly alter the coumarin content of cinnamon. The risk factor remains the total amount of Cassia cinnamon consumed over time, regardless of whether it is cooked or raw.

For mild symptoms like stomach upset, discontinuing use and monitoring your condition is often sufficient. For severe symptoms like signs of liver damage or allergic reactions, seek immediate medical attention.