Understanding Nutrition: What are the signs of too much cinnamon?

October 26, 2025 •

4 min read

According to the European Food Safety Authority, the tolerable daily intake of coumarin, a compound found in high amounts in common Cassia cinnamon, is approximately 0.1 mg per kg of body weight, making it easy to exceed with heavy use. It is important to know what are the signs of too much cinnamon? to prevent potential health issues.

Quick Summary

Excessive consumption of Cassia cinnamon can lead to adverse health effects due to high coumarin levels. Symptoms range from liver damage and oral irritations to dangerously low blood sugar and breathing difficulties. The safer Ceylon variety contains minimal coumarin.

Key Points

Cassia vs. Ceylon: The primary risk comes from Cassia (regular) cinnamon due to its high coumarin content, which can damage the liver in large amounts, unlike the safer Ceylon variety.
Watch for Liver Damage: Signs of excessive Cassia intake include nausea, abdominal pain, fatigue, and in severe cases, jaundice, indicating liver toxicity.
Beware of Low Blood Sugar: Large quantities of cinnamon can cause a significant drop in blood sugar, which is particularly dangerous for people with diabetes.
Recognize Allergic Reactions: Cinnamaldehyde in cinnamon can cause oral and skin irritations, such as mouth sores or hives, in sensitive individuals.
Avoid Inhaling Powder: Inhaling dry cinnamon powder is extremely dangerous and can lead to choking, lung inflammation, and aspiration pneumonia.
Mind Medication Interactions: High doses can interfere with medications for diabetes, heart disease, and those that affect the liver or thin the blood.
Practice Moderation: Limit Cassia cinnamon to about half a teaspoon per day or opt for the safer, lower-coumarin Ceylon variety for regular or heavy use.

Cinnamon's Dark Side: When a Healthy Spice Becomes Harmful

Cinnamon is a beloved spice, lauded for its warm flavor and potential health benefits, such as supporting blood sugar management and providing anti-inflammatory effects. However, the key to enjoying this spice safely lies in moderation and understanding the critical differences between the types of cinnamon available. The primary concern with high intake is the coumarin content, a natural compound that can be toxic to the liver in large doses. While a sprinkle on your oatmeal is generally harmless, consuming high amounts, particularly from concentrated sources like supplements, can lead to serious health problems. It's crucial for consumers to recognize when their love for cinnamon has turned into an overindulgence.

The Critical Difference Between Cassia and Ceylon

Most of the cinnamon sold in grocery stores in the United States is Cassia cinnamon, a cheaper and more widely available variety. The critical difference lies in its high coumarin content. Ceylon, or "true" cinnamon, on the other hand, contains only trace amounts of this compound. Therefore, the health risks associated with excessive cinnamon consumption are almost exclusively tied to the Cassia variety. For regular or heavy users of cinnamon, choosing Ceylon is the safest option. If a product label simply says "cinnamon," it is most likely the high-coumarin Cassia type.

The Health Risks and Signs of Overconsumption

Liver Damage and Coumarin Toxicity

One of the most significant risks of consuming too much Cassia cinnamon is liver damage, or hepatotoxicity. High levels of coumarin can overwhelm the liver's detoxification processes over time. The signs of liver stress can be subtle at first but can escalate. Watch for the following indicators:

Nausea and abdominal discomfort: Persistent upset stomach or pain in the upper right abdomen can be an early sign.
Fatigue: Unusual or chronic tiredness may indicate liver strain.
Jaundice: A yellowing of the skin and eyes is a more advanced sign of liver dysfunction.
Dark urine and pale stools: Changes in the color of waste can indicate issues with the liver's bile production.

Oral and Skin Irritation

Cinnamaldehyde, another compound in cinnamon, can trigger allergic reactions in sensitive individuals. This is particularly noted with prolonged or heavy exposure, such as from using cinnamon-flavored gums, candies, or toothpaste. Symptoms can include:

Mouth sores (cinnamon stomatitis): Redness and swelling in the mouth or on the lips can occur.
Allergic skin reactions: This can manifest as hives, itching, or redness.

Dangerous Drop in Blood Sugar

Cinnamon is known for its ability to lower blood sugar and improve insulin sensitivity. While beneficial in moderation, excessive intake can cause blood sugar levels to drop too low, a condition called hypoglycemia. This is especially dangerous for individuals with diabetes who are already taking medication to control their blood sugar. Signs of dangerously low blood sugar include:

Tiredness and dizziness
Sweating and shaking
Rapid heartbeat
Headaches
Fainting in severe cases

Breathing Problems from Inhalation

Inhaling a large amount of ground cinnamon, as seen in the dangerous "cinnamon challenge," can cause significant respiratory issues. Cinnamon is difficult for the lungs to break down, and inhalation can lead to irritation and inflammation, potentially resulting in aspiration pneumonia. Those with asthma or other respiratory conditions are at a higher risk. This can permanently scar the lungs.

Interference with Medications

High doses of cinnamon can interact with certain medications, intensifying their effects and potentially causing harm. This is particularly relevant for those taking:

Blood thinners: Coumarin has anticoagulant properties, which can cause excessive bleeding when combined with blood-thinning medications like warfarin.
Diabetes medications: Cinnamon can enhance the effects of these drugs, increasing the risk of hypoglycemia.
Liver-affecting medications: Combining excessive cassia cinnamon with drugs like acetaminophen or statins, which are processed by the liver, increases the risk of liver damage.

Comparison: Ceylon vs. Cassia Cinnamon


Feature	Ceylon (True) Cinnamon	Cassia (Regular) Cinnamon
Origin	Mainly Sri Lanka	Primarily China and Indonesia
Appearance	Light brown, thin, and papery layers that are easily crumbled.	Darker reddish-brown, thick, and hard with a single curl.
Flavor	Subtle, sweet, and mild with floral undertones.	Stronger, spicier, and more pungent flavor.
Coumarin Content	Very low, making it safe for regular consumption.	High, posing a risk of liver damage with excessive use.
Common Use	Desserts, pastries, and delicate dishes.	Savory dishes, baked goods, and robust recipes.
Price	More expensive due to delicate harvesting.	Much cheaper and widely available.

Safe Practices for Cinnamon Consumption

To enjoy cinnamon's health benefits without the risks, follow these guidelines:

Choose Ceylon: Whenever possible, purchase Ceylon cinnamon, especially if you plan to use it regularly or in larger amounts.
Monitor Intake: If you use Cassia cinnamon, stick to a maximum of about half a teaspoon daily to stay within safe coumarin levels.
Be Aware of Supplements: Cinnamon supplements often contain concentrated extracts that can have dangerously high coumarin levels. Always consult a healthcare provider before taking supplements, especially if you have pre-existing health conditions or take other medications.
Avoid Dry Powder: Never attempt to inhale dry cinnamon powder, as this poses a serious respiratory risk.
Listen to Your Body: Pay attention to any unusual symptoms like stomach upset, dizziness, or mouth sores. If you suspect an adverse reaction, reduce your cinnamon intake or switch to Ceylon.

Conclusion

While a sprinkle of cinnamon adds flavor and potential benefits to your diet, consuming too much, particularly the high-coumarin Cassia variety, can have serious health consequences. Recognizing what are the signs of too much cinnamon?—including liver issues, oral irritations, and low blood sugar—is essential for safe consumption. By understanding the differences between Ceylon and Cassia and practicing moderation, you can enjoy this ancient spice's goodness without the risk. For reliable, comprehensive information on cinnamon and other supplements, consult resources like the National Center for Complementary and Integrative Health.

Frequently Asked Questions

Coumarin is a natural flavoring compound found in Cassia cinnamon. In high doses, it can be toxic to the liver, potentially causing damage over time. Ceylon cinnamon contains much lower levels, making it the safer choice.

Yes, some people may experience mouth sores, known as cinnamon stomatitis, from consuming high amounts of cinnamaldehyde, a compound in cinnamon. This is often associated with products that have strong cinnamon flavoring.

While there is no official consensus, experts suggest that a daily intake of around half a teaspoon of Cassia cinnamon or less is generally safe. For Ceylon cinnamon, higher amounts are considered safer due to its low coumarin content.

Yes, cinnamon can lower blood sugar levels. While this can be a benefit in moderation, consuming too much can cause a dangerous drop in blood sugar, especially for individuals taking diabetes medications.

Ceylon cinnamon sticks are thin, soft, and roll into multiple layers, while Cassia sticks are thicker, harder, and form a single, hollow layer. Ceylon also has a lighter color and milder flavor.

Yes, inhaling large quantities of dry, ground cinnamon powder can irritate the throat and lungs. This can cause coughing, gagging, and in severe cases, lung inflammation or aspiration pneumonia.

Excessive cinnamon can interact with blood thinners, diabetes medications, and certain drugs processed by the liver, like statins. Always consult a doctor if you are on medication and considering high cinnamon intake.

Cinnamon supplements often contain concentrated amounts of cinnamon, and sometimes high levels of coumarin, depending on the type used. It is best to consult a healthcare provider before taking supplements, especially if you have underlying health conditions.