While you might associate cinnamon with sweet treats and beverages, it actually has a long history of use for a variety of medicinal purposes. The FDA has given cinnamon the status of GRAS -- generally regarded as safe. This does not mean, however, that it does not carry any concerns -- certain side effects and medication interactions have been observed. Concerns about excess cinnamon intake typically relate to supplementing and using cinnamon-containing products rather than using it in food form. If you have an interest in using natural treatments such as cinnamon for any health issue, you should consult a health care professional well-versed in natural therapies, such as a naturopathic physician.
Dosage Guidelines
According to Drugs.com, a site that compiles information from various medical databases, no significant adverse side effects were observed in dosages up to 6,000 mg daily. This does not mean that any dosage under this is automatically safe -- people react to supplements and drugs differently. If you notice any unusual symptoms after using cinnamon supplements, discontinue use or seek guidance on a modified dosage.
Hypoglycemic Effects
Cinnamon appears to activate insulin receptor sites in cells, which facilitates the removal of sugar from the bloodstream and into the cells for energy. This effect on blood sugar could make it potentially useful for managing diabetes. Taking excess cinnamon could cause an excessive drop in blood sugar. This is particularly true if you take cinnamon at the same time as blood-sugar-lowering medications. When using natural supplements that exert similar effects as prescription drugs, you might require adjustments in your medication dosages, and only your doctor can safely make these changes -- do not do this on your own.
Medication Interactions
Cinnamon also naturally contains coumarin, the primary component of blood-thinning medications, and Memorial Sloan Kettering Cancer Center reports this could theoretically affect blood clotting. Do not use cinnamon at the same time as anticlotting drugs. Drugs.com notes laboratory tests found cinnamon affected the dissolution rate of the antibiotic tetracycline, which means using it at the same time as this drug could reduce its effectiveness.
Vasomotor Stimulation
The vasomotor center of the brain controls various bodily processes such as breathing and heart rate. Drugs.com notes excessive consumption of cinnamon has been shown to stimulate this area of the brain, leading to increased heart rate, breathing rate, perspiration and intestinal movement.
Problems Associated with Oral and Topical Use
Adverse effects like mouth sores, gingivitis and stomatitis -- an inflammation of any of the structures of the mouth such as the lips and tongue -- have been reported from using cinnamon toothpastes, gums and candies. Using cinnamon products topically has been reported to cause contact dermatitis.
