pediaCinnamon bark oil (cinnamon bark oil), Cinnamomum verum J.Presl (synonym: Cinnamomum zeylanicum Blume, Lauraceae family) is a warm, spicy and intensely aromatic essential oil obtained by steam distillation from the inner bark of the tree. Its main component is cinnamaldehyde (65-80%), one of the most researched essential oil components in scientific literature. With a 4000-year history of use from ancient Egypt to modern food preservation, cinnamon has become one of mankind's most valued spices—during the Roman Empire, it was traded at prices equivalent to gold.
This article is not a product promotion. Its purpose is to provide an independent framework regarding the scientific position of cinnamon bark oil in the literature. The information contained in this article contains no treatment claims.
Botanical source and history
Cinnamomum verum: true cinnamon
Cinnamomum verum J.Presl (formerly: C. zeylanicum), belonging to the Lauraceae (laurel) family, is a tropical tree native to Sri Lanka. The name "Zeylanicum" derives from Ceylon, the former name of Sri Lanka. It is an evergreen tree reaching 10-15 meters in height. When the inner bark is dried, it curls into the iconic "cinnamon stick" form.
Ceylon cinnamon vs. Cassia cinnamon: a critical distinction
Two different types of cinnamon are confused in the global market: Ceylon cinnamon (C. verum—"true cinnamon," Sri Lankan origin) and Cassia cinnamon (C. cassia—"Chinese cinnamon," cheaper and more common). This distinction is important from a cosmetic safety perspective because Cassia cinnamon contains significantly more coumarin than Ceylon cinnamon—coumarin carries hepatotoxic (liver toxic) potential. EU regulation sets coumarin limits in food products. In cosmetic INCI, "Cinnamomum Zeylanicum Bark Oil" generally refers to Ceylon cinnamon.
History: a spice worth its weight in gold
Cinnamon's written history stretches back to around 2000 BCE to ancient Egypt—where it was used in mummification processes and as incense. In traditional Chinese medicine (TCM), "gui zhi" (cinnamon twig) has been used for at least 2000 years. In Ayurvedic medicine, "dalchini" appears in traditional practices. In the Roman Empire, cinnamon was a luxury commodity traded at prices equivalent to gold. Cinnamon held an important place in Ottoman cuisine and court medicine, and in Turkish culture remains an indispensable spice in sahlep, boza, and desserts.
Chemical profile
Bark oil vs. leaf oil: different components
Different parts of the cinnamon tree yield essential oils of different composition—this distinction is of critical importance from a cosmetic safety standpoint:
- Bark oil: Main component cinnamaldehyde (65-80%), eugenol (2-5%), linalool (1-7%). Warm, spicy, sweet scent. Strong irritant potential.
- Leaf oil: Main component eugenol (70-90%), cinnamaldehyde (1-5%). Clove-like scent. Different safety profile compared to bark oil.
In Chailea Cinnamon Bark Soap, the INCI lists "Cinnamomum Zeylanicum Bark Oil"—indicating bark oil is used.
Cinnamaldehyde: the key component
(E)-Cinnamaldehyde (trans-cinnamaldehyde, C₉H₈O), which constitutes 65-80% of cinnamon bark oil, is an aromatic aldehyde and the primary source of cinnamon's characteristic warm-sweet scent. In GC-MS analyses, the major components of cinnamon bark oil are reported as: (E)-cinnamaldehyde (65-80%), linalool (1-7%), eugenol (2-5%), β-caryophyllene (1-6%), eucalyptol/1,8-cineole (1-5%), and cinnamyl acetate (1-4%).
Position in scientific literature
Antimicrobial research
Cinnamon bark oil is one of the most extensively studied essential oils in scientific literature for antimicrobial activity (this does not constitute a cosmetic efficacy claim). In vitro studies have examined gram-positive (S. aureus, L. innocua, B. cereus) and gram-negative (E. coli, S. typhi, P. aeruginosa) bacterial models. The possible effects of cinnamaldehyde on bacterial cell membrane integrity and ATPase activity have been investigated in vitro studies (does not constitute a cosmetic efficacy claim).
Microbiological research (in vitro)
Cinnamon bark oil has been examined in vitro on model microorganisms such as Candida albicans and Aspergillus species (does not constitute a cosmetic efficacy claim). In the field of food preservation, cinnamon oil is being researched as a natural alternative to synthetic antifungal agents.
Anti-inflammatory research
In a study published by Han and Parker (2017) in Phytotherapy Research, the anti-inflammatory activity of cinnamon bark essential oil (CBEO) was evaluated in human dermal fibroblast cells. The study reported that CBEO significantly inhibited the production of inflammatory biomarkers such as VCAM-1, ICAM-1, MCP-1, and IP-10. Additionally, genome-wide gene expression analysis showed that over 200 genes were regulated by CBEO.
Jayaprakasha and Rao (2011): comprehensive review
In a comprehensive review published by Jayaprakasha and Rao (2011) in Critical Reviews in Food Science and Nutrition, the chemistry, biosynthesis, and biological activities of C. zeylanicum were evaluated. The review comprehensively addressed studies on cinnamon's biological activities.
Safety profile and warnings
Skin irritation and sensitization: THE MOST IMPORTANT WARNING
Cinnamon bark oil has one of the highest skin irritation potentials among essential oils. Cinnamaldehyde is a potent skin sensitizer and, while not listed among the 26 components requiring allergen labeling in the EU Cosmetic Regulation (EC/1223/2009), concentration limits have been set by IFRA (International Fragrance Association). Undiluted (neat) application should never be performed. In cosmetic formulations, it is used in very low concentrations (0.01-0.5%). Patch testing is mandatory for sensitive skin.
Mucous membranes and eye contact
Cinnamon bark oil must be kept away from mucous membranes and the eye area. Use on the mouth and genital area is not recommended.
Pregnancy and children
Use of cinnamon bark oil is not recommended in pregnant women, nursing mothers, or young children (under 6 years of age). Uterine stimulant potential of cinnamaldehyde has been reported.
Coumarin note
Cassia cinnamon contains high coumarin; Ceylon cinnamon contains very low coumarin. Ceylon cinnamon should be preferred in cosmetic use. EU coumarin limits are established for food products; no specific coumarin limit exists for cosmetic products, but it is considered in safety evaluation.
Cinnamon bark oil in soap-making
Addition method and ratio
Cinnamon bark oil is used in very low proportions in soap-making—0.5-2% of the total oil quantity is recommended. Higher ratios (3%+) may cause skin irritation. It is added at trace stage. In an alkaline environment, cinnamaldehyde may undergo certain transformations over time.
Properties it imparts to soap
Cinnamon bark oil imparts a warm, spicy, sweet, and "Christmas" scent to soap. In terms of color, it gives soap a slight yellowish-brown tone. Its scent retention capacity is good—much more lasting than citrus oils. Cinnamon bark oil tends to accelerate trace—quick working is required.
Compatible blends
Cinnamon oil: with orange creates "warm citrus" (the most classic combination—mulled wine/winter theme), with vanilla creates "sweet-spicy" (snickerdoodle theme), with clove + ginger creates "spice blend" (gingerbread theme), and with coffee creates "warm-roasted" combinations.
Frequently asked questions
What is cinnamon bark oil?
Cinnamon bark oil is an essential oil obtained by steam distillation from the inner bark of the Cinnamomum verum (Ceylon cinnamon) tree, rich in cinnamaldehyde (65-80%).
Is cinnamon bark oil safe on skin?
When used in very low concentrations (0.01-0.5%) and with proper dilution, it is generally well tolerated. However, it is among the essential oils with the highest irritation potential. Patch testing is mandatory. Undiluted application must never be performed.
What is the difference between Ceylon and Cassia cinnamon?
Ceylon cinnamon (C. verum) is "true cinnamon" and contains low coumarin. Cassia cinnamon (C. cassia) is cheaper and contains high coumarin. Ceylon cinnamon should be preferred in cosmetic use.
What does cinnamon bark oil do in soap?
It imparts a warm, spicy scent and slight brown tone to soap. It is used at 0.5-2% ratios. Its scent retention capacity is good. The "warm citrus" combination with orange oil is the most classic blend.
Chailea products containing this component
- Natural Cinnamon Bark Soap 100 g
References
1. Han, X., & Parker, T. L. (2017). Antiinflammatory Activity of Cinnamon (Cinnamomum zeylanicum) Bark Essential Oil in a Human Skin Disease Model. Phytotherapy Research, 31(7), 1034-1038. doi:10.1002/ptr.5822
2. Jayaprakasha, G. K., & Rao, L. J. (2011). Chemistry, biogenesis, and biological activities of Cinnamomum zeylanicum. Critical Reviews in Food Science and Nutrition, 51(6), 547-562. doi:10.1080/10408391003699550
3. Doyle, A. A., & Stephens, J. C. (2019). A review of cinnamaldehyde and its derivatives as antibacterial agents. Fitoterapia, 139, 104405.
4. IFRA (International Fragrance Association) — Standards on cinnamaldehyde usage limits.