Studies done in people don’t clearly support using cinnamon for any health condition.

A 2019 review of 18 studies of supplementation in people with diabetes suggested that it could reduce blood sugar but didn’t have a significant effect on hemoglobin A1C, which reflects blood sugar levels over a longer period of time. However, it’s unclear whether these findings are meaningful because 10 of the studies didn’t identify the type used, and 8 of the studies were judged to be of low quality for other reasons.

It’s uncertain whether cinnamon is helpful for weight loss or for controlling blood levels of cholesterol and related lipids. There’s not enough evidence to show whether it is helpful for irritable bowel syndrome.

It’s unclear whether cassia cinnamon is effective as an insect repellent.

Side Effects Of Cinnamon

Supplements appear to be safe when consumed in the amounts commonly used in foods as a spice or flavoring agent. Use in larger amounts or for long periods of time is sometimes associated with side effects, most commonly gastrointestinal problems or allergic reactions.

Cassia cinnamon contains a chemical called coumarin, which can be harmful to the liver. Some cassia cinnamon products contain high levels of this substance. In most cases, consuming cassia cinnamon doesn’t provide enough coumarin to cause significant problems. However, prolonged use of cassia cinnamon could be an issue for sensitive people, such as those with liver disease.

Little is known about whether it’s safe to use cassia cinnamon during pregnancy or while breastfeeding. Ceylon cinnamon may be unsafe for use during pregnancy if consumed in amounts greater than those commonly found in foods. Little is known about whether it’s safe to use Ceylon cinnamon during breastfeeding in amounts greater than those commonly found in foods.

It should not be used in place of conventional medical care or to delay seeking care if you have health problems. This is particularly true if you have diabetes.


Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.