Cinnamon Oil
Cinnamon oil (Cinnamomum species): what the sources say about skin irritation and allergy, the limited human research, bark versus leaf, and why it is never for swallowing.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Safety first. Cinnamon oil is a concentrated essential oil. Poison Control says misuse of essential oils can cause serious poisoning, and that many essential oils can cause rashes on the skin. [1] NCCIH (the US National Center for Complementary and Integrative Health) reports that some types of topical cinnamon oil or powder may cause skin irritation or contact dermatitis. [2] We do not advise swallowing cinnamon oil or any essential oil. If someone may have swallowed it, call Poison Help at 1-800-222-1222 (US); call 911 for collapse, a seizure or trouble breathing. [1] See Poisoning: what to do first.
What cinnamon oil is
Cinnamon oil is a concentrated plant oil that keeps the smell of cinnamon. It is not the same thing as the spice in a kitchen jar, and it is not the same as cinnamon tea or a cinnamon supplement. Cinnamon as a spice and food is covered in Cinnamon (herbs and botanicals) and Cinnamon as a food. Results for the spice, a capsule or an extract do not carry over to the oil.Which plant, which part
"Cinnamon" is not one plant. NCCIH names two main species: Ceylon cinnamon, Cinnamomum verum (also called C. zeylanicum), grown mainly in Sri Lanka, and cassia cinnamon, Cinnamomum aromaticum (also called C. cassia), grown in southeastern Asia. [2] GBIF, the global plant name database, lists both as accepted species in the laurel family (Lauraceae). [3][4] Cinnamon comes from the bark, and NCCIH notes that bark, leaves, flowers, fruits and roots have all been used. [2]Cinnamon oil can be made from bark or from leaf, and the two can differ in chemistry. NCCIH says cinnamon products may not clearly indicate which species or parts were used, and that types and parts differ in chemical makeup in ways that can affect people. [2] The sources we read do not compare bark oil and leaf oil safety directly, so we cannot say one is milder than the other.
Traditional use
Traditional use only, not proof. NCCIH says the bark, leaves, flowers, fruits and roots of cinnamon have a long history in traditional medicine and cuisine in many parts of the world, including China, India and Persia (Iran). [2] The sources we read do not describe the traditional use of the oil itself.What research shows
NCCIH says research does not clearly support using cinnamon for any health condition. [2] That statement covers cinnamon in general, mostly spice and supplements, not the oil.| Use | What the source found | Strength of evidence | Population and form studied |
|---|---|---|---|
| Nausea after cesarean section | In a double-blind trial, inhaling cinnamon leaf oil with oxygen did not reduce nausea or vomiting compared with the other groups in the first 6 hours. [5] | Evidence against a benefit in this trial; small | 60 patients having cesarean section; inhaled cinnamon leaf oil 8% with 28% or 40% oxygen [5] |
| Oral yeast infection (candidiasis) | A trial of a mouthwash and spray made with Cinnamomum zeylanicum oil compared it with an antifungal medicine; both showed clinical improvement. [6] | Promising but limited | 36 people, 18 per group; a finished mouthwash and spray product, not bottled oil [6] |
| Mosquito repellent | NCCIH says it is unclear whether cassia cinnamon is effective as a mosquito repellent. [2] | Insufficient evidence | Cassia cinnamon, applied to skin [2] |
| Diabetes, weight loss, infection, pain, colds | Proper evidence not found for the oil. We searched PubMed for cinnamon oil and cinnamon essential oil trials in people and read the NCCIH page. Studies on cinnamon supplements are hard to interpret because the species or part is often unclear. [2] | Insufficient evidence | Not applicable |
Laboratory findings that cinnamon oil affects microbes in a dish are not evidence of an effect in people. See Essential oils: human versus lab research.
Forms, and why the form matters
Sources we read describe cinnamon oil in inhaled trials and in finished products such as mouthwash. We give no dilution or amount. Concentration and carrier differ by product, and a pharmacist or clinician can advise. See diluting essential oils: what sources say.Official statements
- NCCIH (US, page read 2026): research does not clearly support cinnamon for any health condition. [2]
- LactMed (US National Library of Medicine): no data on cinnamon safety in nursing mothers or infants. [9]
Frequently asked questions
Is cinnamon oil safe on the skin?
It can irritate the skin or cause allergic contact dermatitis, according to NCCIH and case reports. [2][7] Stop using any oil that causes a rash and wash it off. [1]
Does cinnamon oil help with nausea, diabetes or infections?
We did not find good human evidence for the oil. One trial of inhaled cinnamon leaf oil found no benefit for nausea after cesarean section. [5] NCCIH says research does not clearly support cinnamon for any condition. [2]
Is cinnamon bark oil different from cinnamon leaf oil?
They come from different parts of the plant and can differ in chemistry. NCCIH says products may not show which part or species was used. [2] We found no source comparing their safety.
Can I swallow cinnamon oil or add it to drinks?
We do not advise swallowing any essential oil. Poison Control warns that essential oil misuse can cause serious poisoning. [1] Call Poison Help at 1-800-222-1222 after a swallowing incident.
Is cinnamon oil safe in pregnancy?
Not shown for the oil. NCCIH calls larger amounts of Ceylon cinnamon unsafe in pregnancy. [2] Ask a clinician.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety
- Skin. Topical cinnamon oil or powder may cause irritation or contact dermatitis, according to NCCIH. [2] A case report describes long-lasting, extensive blistering dermatitis beginning within 24 hours of a spa mud bath containing cinnamon essential oil; later patch tests were positive to cinnamon, eugenol, cinnamic alcohol and cinnamic aldehyde. [7]
- Allergy. In a Finnish clinic series, six people had delayed contact allergy to cinnamon, one from airborne exposure, and five reacted to cinnamal (the main flavor chemical) and to a fragrance mix. [8] Reactions can cross over to eugenol and other fragrance chemicals; see strong oils and skin reactions.
- Breathing. Any allergic reaction with difficulty breathing is a medical emergency. [1]
- Liver and coumarin. NCCIH says coumarin, found in cassia cinnamon, has been reported to interact with the liver, and that sensitive people such as those with liver disease could be affected by prolonged use of cassia. [2] That statement is about cassia cinnamon products; the sources we read do not say how much coumarin is in the oil. See liver safety.
- Medicines. NCCIH says there are theoretical reasons that some components of cinnamon may interact with an anticancer medicine or nicotine. [2] Poison Control says essential oils may interact with medications. [1] See how interactions work.
- Pregnancy and breastfeeding. NCCIH says larger amounts of Ceylon cinnamon in pregnancy are considered unsafe, and little is known about larger amounts while breastfeeding. [2] LactMed says no data exist on cinnamon safety in nursing mothers or infants. [9] These statements are about cinnamon, not the oil. See oils in pregnancy and breastfeeding.
- Children. Poison Control says children have thin skin and immature livers, which might make them more susceptible to toxic effects than adults. [1] Keep oils locked away from children and pets.
- Surgery: tell the surgical team about any oil product you use.
References
- Essential oils: Poisonous when misused (Poison Control). Read 2026-10-23.
- Cinnamon: Usefulness and Safety (NCCIH, NIH). Read 2026-10-23.
- Cinnamomum verum J.Presl (GBIF Backbone Taxonomy). Read 2026-10-23.
- Cinnamomum aromaticum Nees (GBIF Backbone Taxonomy). Read 2026-10-23.
- The Effect of Combination of Cinnamon and Oxygen Different Concentrations Inhalation Aromatherapy on Nausea in Cesarean Section Under Spinal Anesthesia: A Clinical Trial. J Perianesth Nurs 2026. Read 2026-10-23.
- Efficacy of essential oil of cinnamon for the treatment of oral candidiasis: A randomized trial. Spec Care Dentist 2021. Read 2026-10-23.
- Mud bath dermatitis due to cinnamon oil. Contact Dermatitis 2005. Read 2026-10-23.
- Occupational allergic contact dermatitis from cinnamon including one case from airborne exposure. Contact Dermatitis 2009. Read 2026-10-23.
- Cinnamon (Drugs and Lactation Database, LactMed, National Library of Medicine). Read 2026-10-23.