Educational information, not medical advice — ask your doctor or midwife.
What is Backhousia citriodora?
Backhousia citriodora is an Australian rainforest tree, better known as lemon myrtle. Its leaves smell strongly of lemon. The leaf is used as a food flavour, a tea, and a source of essential oil.
The tree grows wild in coastal Queensland. It is now farmed for leaf and oil. You will meet it in tea blends, spice mixes, soaps and cleaning sprays.
Here is the honest verdict. Lemon myrtle leaf is a well-liked flavouring with a long food record. As a medicine, human evidence is thin, and long traditional use is not proof that it works or that it is safe.
How might lemon myrtle work?
Almost every health claim made for lemon myrtle traces back to citral, the main part of its oil. In test tubes, citral slows the growth of many bacteria, yeasts and moulds. Whether that happens on human skin or inside the body is not established.
Cell studies also report that citral can lower some markers of swelling. Animal work hints at mild calming and pain-dulling effects. This is early-stage research and does not show a benefit in people.
There is a catch worth knowing. In cell studies, strong citral solutions damage human skin cells as well as microbes. The same strength that kills germs in a dish can irritate you.
The tea is a much weaker thing than the oil. A cup of leaf tea gives you only a trace of citral. Any effect from tea, if there is one, is likely to be small.
What forms does it come in?
- dried whole leaf or ground leaf, for cooking and tea - tea bags and herbal tea blends - essential oil, steam distilled from the leaf - diluted oil in soaps, creams, shampoos and cleaning sprays - flavour extracts used in drinks, sweets and sauces - capsules of powdered leaf, sold far less often
Food-grade dried leaf is the mildest form by a wide margin. The essential oil is the strongest. Do not treat the two as the same product.
What did tradition claim for it?
Aboriginal peoples of coastal Queensland used lemon myrtle leaf as a food flavour and in traditional healing. Written accounts describe leaf teas and crushed leaf used for colds and for skin complaints. These reports were passed on by word of mouth and recorded much later by outsiders.
Settler cooks picked it up as a lemon substitute. From the 1990s it was grown as a commercial bush food crop in Queensland and New South Wales.
Growers then began selling the essential oil for cleaning, skin care and fragrance. That is where most modern interest in the plant comes from.
Stop using it and see a doctor if:
- a rash spreads, blisters or weeps - redness or swelling keeps getting worse after you stop - the oil gets in your eye and stinging continues after rinsing - you wheeze, cough or feel short of breath after breathing the vapour - a skin infection is not clearing, or you have fever with it
Get urgent help if someone swallows the essential oil. Call your local poison centre or emergency number straight away. Do not make the person vomit.
Seek emergency care for swelling of the lips, tongue or throat, or for trouble breathing.
In Australia, lemon myrtle leaf is an ordinary food and is widely sold as tea and spice. In the UK, EU and US it is sold as a food, herbal tea or flavouring.
The essential oil is sold as a cosmetic and fragrance ingredient, not as a medicine. No medicines regulator has approved lemon myrtle to treat any disease.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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