Lemon Myrtle (Backhousia citriodora)
An intensely lemon-scented Australian oil popular for diffusing and DIY cleaning recipes, stronger than true lemon oil.
How to use it
3–5 drops for a sharp, clean lemon scent — a favorite for air-freshening blends.
Dilute to 1% or less in a carrier oil and patch-test — a stronger sensitizer than most citrus.
Use in small proportions alongside gentler oils like lavender rather than as the main note.
Safety in detail
- Max dermal use
- Very low (~0.7%) — exceptionally high citral, a strong sensitiser
- Phototoxic
- No
- Among the highest-citral oils in existence, so it's a strong skin sensitiser and irritant — dilute very low and patch-test.
- Its intensity means a very small amount is plenty; overuse can irritate the airways too.
- Not phototoxic. Keep out of reach of children.
Sources: Foods review (2021) · Food and Chemical Toxicology study on Backhousia citriodora (2002)
Composition & chemistry
Aggregated from 4 GC-MS samples across 3 peer-reviewed open-access studies (2021–2024). Figures are the distribution across those samples — median with interquartile range — not a single reading.
- Oxygenated monoterpene 95.5%
- Unclassified 3%
- Aliphatic / small aromatic 1.1%
- Monoterpene hydrocarbon 0.4%
| Constituent | Median | Typical range | Max | Detected in |
|---|---|---|---|---|
| geranial ↗ C10H16O | 47.3% | 45.6–48.9% | 50.5% | |
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| neral ↗ C10H16O | 38.3% | 37.6–39.0% | 39.8% | |
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| 6-methyl-5-hepten-2-one ↗ C8H14O | 1.0% | 0.8–1.3% | 1.6% | |
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| linalool ↗ C10H18O | 0.6% | 0.5–0.6% | 0.7% | |
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| myrcene ↗ C10H16 | 0.4% | 0.3–0.4% | 0.4% | |
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+ 4 more compounds reported across the dataset.
3 peer-reviewed sources behind these figures
- Rahman MM, Wills RBH, Bowyer MC, Vuong VQ, Golding JB, Kirkman T, Pristijono P. (2023). Efficacy of Lemon Myrtle Essential Oil as a Bio-Fungicide in Inhibiting Citrus Green Mould. Plants (Basel, Switzerland).
- Nagata T, Satou T, Hayashi S, Satyal P, Watanabe M, Riggs B, Saida Y. (2024). Citral in lemon myrtle, lemongrass, litsea, and melissa essential oils suppress the growth and invasion of breast cancer cells. BMC complementary medicine and therapies.
- Southwell I. (2021). Backhousia citriodora F. Muell. (Lemon Myrtle), an Unrivalled Source of Citral. Foods (Basel, Switzerland).
Every figure above traces to a named table in one of these open-access papers. How this was built →
- Citral (geranial + neral) — the dominant lemony aldehyde pair (90%+), giving the purest 'lemon' scent of the citral oils — and the main sensitiser to respect Foods review (2021)
It has one of the highest citral concentrations of any essential oil on the market.
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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Lemon myrtle oil and its citral have been studied for antimicrobial activity in the laboratory. A toxicity study also established the need to keep dilution low — both are chemistry/safety findings, not health claims.
Food and Chemical Toxicology study (2002)
Evidence & sources
Peer-reviewed research on Lemon Myrtle's chemistry and safety. These describe composition and documented effects — not health or treatment claims.
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Lemon myrtle is one of the most citral-rich essential oils known, typically over 90% citral — the source of its intense true-lemon aroma and its strong skin caution.
Foods review (2021)
Frequently asked questions
Is lemon myrtle stronger than lemongrass?
Yes — lemon myrtle is even higher in citral than lemongrass (often 90%+), giving it a purer, more intense lemon aroma. That also makes it more sensitising, so it needs even lower dilution. Foods review (2021)
Why must lemon myrtle be so heavily diluted?
Its very high citral content is a strong skin sensitiser. A toxicity study confirmed the need to keep concentrations low — around 0.7% or less on skin, with a patch test first. Food and Chemical Toxicology study (2002)
Is lemon myrtle phototoxic?
No — despite the citrusy name it isn't a citrus oil and isn't phototoxic. The main precaution is its very high citral content, which calls for low dilution. Foods review (2021)
Gallery
Lemon Myrtle (Backhousia citriodora) comes from a rainforest tree native to the subtropical coast of Queensland and New South Wales, Australia, where it was used by Aboriginal communities long before European settlers took an interest in it. The tree’s leaves are steam-distilled to produce an oil with one of the highest citral concentrations of any essential oil on the market.
Why it smells so intensely lemon
Citral — the combined neral and geranial that give citrus its lemony character — typically makes up 90% or more of lemon myrtle oil, compared to roughly half that in true lemon (Citrus limon) peel oil. That’s why lemon myrtle smells so much sharper and more concentrated than lemon itself, even though neither plant is botanically related to actual lemons.
In the diffuser
3–5 drops delivers a sharp, unmistakably lemony aroma — a favorite base note for cleaning-spray and air-freshening recipes precisely because it reads as “clean” so effectively.
On skin
Because of its very high citral content, lemon myrtle is more likely to irritate skin than milder citrus oils like sweet orange. Keep topical dilution to 1% or less and always patch-test first — see our allergy and safety guide for more on citral sensitivity.
What pairs well
Its intensity works best in small proportions alongside gentler oils — eucalyptus, tea tree, or lavender — rather than as a large share of a topical blend.
A note on strength
This is one of the more potent single oils in a typical collection — a little goes further than with gentler oils like lavender or sweet orange, so start conservatively in both the diffuser and any DIY recipe.