Common Names: cinnamon, cinnamon bark, Ceylon cinnamon, cassia cinnamon

Scientific Names: Cinnamomum verum (also called Cinnamomum zeylanicum and Laurus cinnamomum), Cinnamomum aromaticum (also known as Cinnamomum cassia)

Background

• Cinnamon is a popular spice obtained from the dried bark of certain Cinnamomum trees. The species Cinnamomum verum, often referred to as “true” cinnamon or Ceylon cinnamon, primarily grows in Sri Lanka. Cassia cinnamon (Cinnamomum aromaticum) is more commonly found in North America and originates from regions in Southeast Asia.

• The bark and other parts of the cinnamon tree, including leaves and roots, have long been used in traditional medicine and cooking practices across various cultures, such as those in China, India, and Iran. Historically, it has been used for ailments like inflammation, nerve discomfort, heart issues, and respiratory troubles.

• In modern times, cinnamon is marketed as a dietary supplement claiming potential benefits for blood sugar support and weight management. Ceylon cinnamon has been explored for managing allergic rhinitis, while cassia cinnamon is sometimes used topically to help repel mosquitoes.

How Much Do We Know?

• A significant number of scientific studies have examined cinnamon, particularly for blood sugar control. Still, many of these studies are difficult to interpret correctly due to a lack of clarity on the type of cinnamon used or which plant part was tested.

What Have We Learned?

• There is no strong scientific evidence that establishes cinnamon as effective for treating any specific health condition.

• Research on whether cinnamon helps with weight management or blood sugar control in people with diabetes is limited and inconclusive. Better-quality studies are needed to determine any clear benefits.

• Early research suggests that a nasal spray containing Ceylon cinnamon extract might ease hay fever symptoms. However, additional research is needed to verify these early findings.

• The ability of cassia cinnamon to work as a mosquito repellent has not been proved and remains uncertain.

What Do We Know About Safety?

• Consuming cinnamon in amounts typically used for flavor in food is generally considered safe. But using it in larger doses or over extended periods has occasionally been associated with digestive issues or allergic responses.

• Participating in the “cinnamon challenge,” which involves swallowing cinnamon powder dry, is risky and can cause serious harm.

• Not all cinnamon-based products clearly state the type of cinnamon included or which part of the plant is used. This matters because specific varieties differ in their chemical makeup, affecting their safety and impact on health.

• Cassia cinnamon contains a compound called coumarin, which has been linked to liver issues in high doses. Although most cassia products contain relatively low coumarin levels, some may have unsafe amounts. Ceylon cinnamon typically has very small traces of coumarin.

• Some individuals have experienced skin irritation or allergic reactions from cinnamon oil or powder when applied to the skin.

• Preliminary studies indicate that cinnamon may interact with certain medications, including those used in cancer treatment or nicotine therapies. If you're on medication, it’s important to talk with your doctor before using cinnamon supplements or related products.

• While modest consumption of cinnamon in food appears safe during pregnancy, high doses of Ceylon cinnamon might pose risks. There is little data about the safety of consuming large quantities of either type while breastfeeding.

Keep in Mind

• Always discuss any supplements or alternative treatments you're considering with your healthcare provider to make informed decisions together.

• Herbal product regulation varies based on their ingredients and how they're intended to be used. Many are sold as dietary supplements, which follow different rules from prescription medications.

• Unlike prescription drugs, dietary supplements do not need approval from the U.S. Food and Drug Administration before they're sold. However, if safety concerns arise, the agency can act to safeguard the public. Makers of supplements are responsible for making sure their products are safe and properly labeled before selling them.

• The requirements for manufacturing and selling dietary supplements are less strict than those for pharmaceuticals, so be careful when choosing and using such products.

For More Information

• Tips for Using Dietary Supplements Safely

• Understanding How Supplements and Medicines Might Interact

• Learning to Interpret Scientific Studies Effectively

NCCIH Clearinghouse

The NCCIH Clearinghouse offers access to trustworthy information about various complementary health approaches, including brochures and links to scientific databases. It does not provide individual medical advice or treatment suggestions.

Toll-free in the U.S.: 1-888-644-6226

TRS: 7-1-1

PubMed®

PubMed®, a resource from the National Library of Medicine, lists thousands of scientific papers and article summaries from medical journals. It is a useful database for exploring health-related research.

Office of Dietary Supplements (ODS), National Institutes of Health (NIH)

The ODS aims to improve public understanding of supplements by supporting research and providing reliable educational material. It offers detailed fact sheets on various vitamins and supplements, like vitamin D and multivitamins.

Key References

• Bosmia AN, Leon KJ. Lung injury related to the “cinnamon challenge” in young adults. Journal of Injury & Violence Research. 2015;7(1):41-42.

• Cassia cinnamon. NatMed Pro. Accessed August 23, 2023.

• Ceylon cinnamon. NatMed Pro. Accessed August 23, 2023.

• Grant-Alfieri A, Schaechter J, Lipshultz SE. Risks of dry cinnamon ingestion by youths: the “cinnamon challenge.” Pediatrics. 2013;131(5):833-835.

• Hajimonfarednejad M, et al. Review of cinnamon-related adverse events. Clinical Nutrition. 2019;38(2):594-602.

• Mousavi SM, et al. Cinnamon's impact on obesity: A systematic review and meta-analysis. Clinical Nutrition. 2020;39(1):123-133.

• Namazi N, et al. Effects of cinnamon on diabetes-related outcomes: A meta-analysis. Complementary Therapies in Medicine. 2019;43:92-101.

• Oketch-Rabah HA, et al. Confusion over cinnamon nomenclature and its implications. Clinical Pharmacology and Therapeutics. 2018;104(3):435-445.

• Paine MF. Studying natural products and predicting drug interactions. Drug Metabolism and Disposition. 2020;48(10):956-962.

• Steels E, et al. Trial of cinnamon extract nasal spray for hay fever. Complementary Therapies in Medicine. 2019;47(102198).

• Yazdanpanah Z, et al. Cinnamon's effect on body weight: A review of clinical trial data. Psychotherapy Research. 2020;34(3):448-463.

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