Reference point
Open a bottle of cajeput oil and put a drop on the back of your hand.
Do this before you read on. An entry only works when you have just smelled the thing.
Airy, cool, clean, and noticeably less harsh than the medicated balm dầu gió. No camphor note.
This entry should be set beside that balm to show that the medicinal family has more than one voice. The balm is sharp and complex; cajeput oil is simple and soft.
It also evaporates faster. After fifteen minutes almost nothing is left on the hand.
How to smell it
Put a drop of cajeput oil on your left hand and a drop of dầu gió on your right. Smell them in turn for five minutes. The biggest difference is that the balm has a lingering cold and cajeput oil does not.
Why this one is hard
Because in Vietnam the word tràm covers two different species, and the two give two different oils. Labels often do not say which, so the same name can mean two things.
Don’t confuse with
This entry
Cajeput oil
Medicinal family
Cajeput oil is simple and soft, mostly cineole. The medicated balm has menthol and camphor, so its cold lasts much longer.
Scientific note
The cajeput oil sold in Vietnam is almost always from Melaleuca cajuputi, rich in 1,8-cineole. That is worth checking on the label, because tea tree is a different species with a different composition — the cajuput entry covers this in detail.
What is worth saying about this particular product is why it is used for young children while eucalyptus is not, although both are rich in 1,8-cineole. The difference lies in concentration and in the minor compounds: cajeput oil has a lower share of cineole than eucalyptus oil, together with a different group of terpenes that softens the sharpness.
To be clear: this explains the difference in sensation; it is not a recommendation for use. Oils containing cineole still have their own safety limits for young children, and the safety pages cover that in detail.
In Vietnamese life
Cajeput oil from Hue is a product tied to newborns in central Vietnam, rubbed on the skin and added to bath water. It is one of the few essential oils Vietnamese people used routinely long before the idea of essential oils became widespread.