Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking Cassia cinnamon if you are pregnant or breast feeding. Stay on the safe side and avoid use.

Children: Cassia cinnamon is POSSIBLY SAFE when taken by mouth appropriately. One gram of cassia cinnamon daily has been used safely in 13-18 year-old adolescents for up to 3 months.

Diabetes: Cassia cinnamon can lower blood sugar levels in people with diabetes. Watch for signs of low blood sugar (hypoglycemia) and monitor your blood sugar carefully, if you have diabetes and use cassia cinnamon in amounts larger than the amounts normally found in food.

Liver disease: Cassia cinnamon contains a chemical that might harm the liver. If you have liver disease, do not take cassia cinnamon in amounts larger than the amounts normally found in food.

Surgery: Cassia cinnamon might lower blood sugar and might interfere with blood sugar control during and after surgery. Stop taking cassia cinnamon as a medicine at least 2 weeks before a scheduled surgery.

Cassia cinnamon is LIKELY SAFE when taken by mouth in amounts commonly found in foods and when taken by mouth in medicinal doses for up to 4 months.

Cassia cinnamon is POSSIBLY SAFE when applied to the skin in the short-term.

Cassia cinnamon is POSSIBLY UNSAFE when taken by mouth in large amounts for a long period of time. Taking large amounts of cassia cinnamon might cause side effects in some people. Cassia cinnamon can contain large amounts of a chemical called coumarin. In people who are sensitive, coumarin might cause or worsen liver disease. When applied to the skin, cassia cinnamon can sometimes cause skin irritation and allergic skin reactions.