Cassia (Cinnamomum cassia)
A warm, sweet-spicy single oil closely related to Cinnamon Bark, often used in cleansing blends and home-cleaning solutions.
How to use it
2–3 drops with orange or lemon — its intensity needs a lighter hand than most spice oils.
A drop or two in a DIY cleaning-spray recipe adds a spicy, fresh note.
A hot oil — keep any topical use to 1% or less in a carrier oil and patch-test first.
Safety in detail
- Max dermal use
- Extremely low — cinnamaldehyde is a strong sensitiser; avoid leave-on skin use
- Phototoxic
- No
- One of the very harshest oils — around 80% cinnamaldehyde. Never apply neat; most practitioners avoid leave-on skin use entirely.
- A strong mucous-membrane irritant: keep away from eyes, nose, and mouth, and diffuse only sparingly.
- Not phototoxic. Keep well out of reach of children.
Composition & chemistry
- (E)-Cinnamaldehyde 80%
- Cinnamyl acetate 5%
- o-Methoxycinnamaldehyde 4%
- Coumarin 3%
- β-Caryophyllene 2%
- Other minor constituents 6%
- (E)-Cinnamaldehyde — the dominant aldehyde behind cassia's hot-spice aroma and its strong skin- and mucous-membrane-irritant potential Industrial Crops and Products study (2011)
Steam-distilled cassia (Cinnamomum cassia) bark oil; even higher in cinnamaldehyde than true cinnamon bark, and among the harshest oils on skin.
Source: Industrial Crops and Products study on cassia oil (2011)In many countries, the "cinnamon" on grocery shelves is more often cassia than true Ceylon cinnamon.
What the research says
An honest read of the published research — what has actually been studied, at what stage. Not medical advice or a promise of results.
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Cassia oil and cinnamaldehyde are studied for antimicrobial activity in the laboratory. These are in-vitro findings; cassia's headline for consumers is its harshness, not a health benefit.
Industrial Crops and Products study (2011)
Evidence & sources
Peer-reviewed research on Cassia's chemistry and safety. These describe composition and documented effects — not health or treatment claims.
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Cassia is even more cinnamaldehyde-dominant than true cinnamon bark, which makes it both intensely aromatic and among the most skin-irritating essential oils.
Industrial Crops and Products study (2011)
Frequently asked questions
Is cassia the same as cinnamon?
They're related and smell similar, but cassia (Cinnamomum cassia) is a different species from true cinnamon (Cinnamomum verum) and is typically even higher in cinnamaldehyde — so it's harsher on skin. Much supermarket 'cinnamon' is actually cassia. Industrial Crops and Products study (2011)
Can I use cassia oil on my skin?
It's best not left on skin at all — at ~80% cinnamaldehyde it's a strong sensitiser and irritant. If used, it must be very heavily diluted and patch-tested; for most people it's a diffuser-only oil, used a drop at a time. Industrial Crops and Products study (2011)
Is cassia phototoxic?
No — it isn't phototoxic. Its real hazard is its very high cinnamaldehyde content, which makes it one of the harshest oils to handle.
Gallery
The Plant
Cassia (Cinnamomum cassia), sometimes called Chinese cinnamon, is native to southern China and closely related botanically to true Cinnamon Bark (Cinnamomum verum), which is more associated with Sri Lanka. The two trees are close enough taxonomically that in many countries, including the United States, “cinnamon” sold in grocery stores is more often cassia than true Ceylon cinnamon — cassia’s bark is thicker, harder, and cheaper to produce at scale.
Extraction & Aroma
The oil is steam-distilled from the bark and shares much of Cinnamon Bark’s warm, sweet-spicy aroma, though cassia tends to read slightly sharper and less complex, with an even higher concentration of cinnamaldehyde, the compound responsible for cinnamon’s characteristic heat and sweetness.
Traditional & Everyday Uses
It’s a common choice for diffusing during cooler months or adding to home-cleaning solutions, where its aroma is welcome and its warming compounds have long made it a folk-tradition addition to cleaning routines.
In the diffuser: 2–3 drops mixed with an orange or lemon oil makes a warm, comforting blend without overwhelming a room — cassia’s intensity means it needs a lighter hand than most other spice oils.
Around the house: a drop or two in a cleaning-spray recipe adds a spicy, fresh note alongside its aromatic appeal, echoing cinnamon’s long folk history as a kitchen and household staple.
Safety Note
Like Cinnamon Bark, cassia is a hot oil that can irritate skin even at moderate dilution, due to its very high cinnamaldehyde content. Keep any topical use to 1% or less in a carrier oil, and patch-test on a small area first — this is one of the oils where under-diluting is a genuinely common mistake.