Lemon Myrtle Essential Oil

Overview

Lemon myrtle essential oil is steam-distilled from the leaves of Backhousia citriodora, a tree native to the subtropical rainforests of eastern Australia. It holds the distinction of being the highest natural source of citral — the compound responsible for “lemon” scent — at 90-98% citral content. For comparison, lemongrass contains roughly 65-80% citral, and actual lemon oil contains only about 2-5%.

This extreme citral concentration makes lemon myrtle the most intensely lemony essential oil available, but it also makes it one of the most potent skin sensitizers among commonly used EOs. Citral (a mixture of the isomers geranial and neral) is a well-documented skin sensitizer, and at the concentrations present in undiluted lemon myrtle, it will cause contact dermatitis in a significant percentage of people. This oil demands respect and careful dosing.

The scent is intensely lemon — cleaner and more “true lemon” than lemongrass, without the grassy undertone. It functions as a top note. The antimicrobial and antifungal activity is exceptionally strong, outperforming tea tree and many other antimicrobial EOs in some in-vitro studies.

What it does in a formula

Lemon myrtle is primarily a functional antimicrobial and antifungal ingredient, not a casual fragrance addition. Its citral content provides potent broad-spectrum activity against bacteria, fungi, and molds. In cleaning products and surface sprays, it is outstanding. In personal care, it must be used at very low concentrations where it still contributes meaningful antimicrobial activity and a clean lemon scent.

In soap making, lemon myrtle is particularly valued because citral holds up better through saponification than the limonene in lemon or orange oils. The result is soap that actually smells lemony after curing — something that lemon essential oil often fails to deliver.

The antifungal properties make it useful in foot care and products targeting fungal skin conditions, always at appropriately low concentrations.

How to use

Add to the oil phase at cool-down (below 45°C). Pre-dilute in carrier oil before adding to your formula — measuring tiny amounts of a neat sensitizing oil is risky.

Dermal safety limit: IFRA recommends a maximum of 0.7% citral in leave-on products. Since lemon myrtle is 90-98% citral, this means a maximum of roughly 0.7% lemon myrtle in any leave-on formulation — and lower is safer.

• Face products: NOT recommended (citral sensitization risk too high for facial skin)
• Body lotions and oils: 0.2-0.5% maximum
• Soap (cold/hot process): 1-2% of total oils (citral partly degrades during saponification)
• Cleaning products: 1-3%
• Diffuser blends: per device instructions
• Foot care products (antifungal): 0.3-0.5%

Blends well with eucalyptus, tea tree, lavender, peppermint, and other citrus oils.

Best for / Worst for

Best for: cold process soap (lemon scent that lasts), natural cleaning products, surface disinfectant sprays, diffuser blends for air purification, foot care, mold-prone environments, products where powerful antimicrobial activity at low concentrations is needed.

Worst for: face products (do not use), leave-on products for sensitive skin, products for children or infants, anyone with known citral sensitivity, products where customers might be tempted to use neat oil on skin, perfumery (too one-dimensional at safe concentrations).

Common pitfalls

Using it at the same rates as other essential oils. This is the most dangerous mistake. Standard EO usage rates of 1-2% are far too high for lemon myrtle in leave-on products. The 90-98% citral content means you hit sensitization thresholds very quickly. Maximum 0.7% in leave-on body products, and realistically 0.2-0.5% is safer.

Adding it to face products. Facial skin is thinner, more reactive, and more frequently exposed. The sensitization risk from citral at any meaningful concentration makes lemon myrtle a poor choice for facial skincare. Use lemon or bergamot FCF instead.

Assuming it is “just lemon.” Customers may expect it to behave like lemon essential oil. It is dramatically more potent and carries different safety considerations. If you sell products containing lemon myrtle, make sure your formulation respects the concentration limits.

Not pre-diluting before measuring. Trying to measure 0.3% of an essential oil from a dropper bottle is imprecise and risks overdosing. Create a 10% dilution in jojoba or fractionated coconut oil first, then measure from that stock solution.

Using it in leave-on products for the scent alone. If you just want a lemon scent in a lotion, lemon or litsea cubeba are safer choices. Reserve lemon myrtle for applications where its superior antimicrobial potency justifies the sensitization risk.

Substitutes

• Lemongrass — also citral-rich (65-80%) but somewhat lower sensitization risk at typical use rates, grassy undertone.
• Litsea cubeba (may chang) — citral-containing (60-80%), softer, sweeter, less intense.
• Lemon — low citral (2-5%), safe at higher rates, but scent fades in soap.
• Citral isolate — pure citral, allows precise dosing, no botanical complexity.
• Eucalyptus lemon (Eucalyptus citriodora) — citronellal-based lemon character, not citral, different safety profile.