Lemon Eucalyptus Oil as an Insect Repellent

If you’re looking for protection against mosquito bites, lemon eucalyptus oil might be a good bet. Extracted from the leaves of a tree native to Australia (Eucalyptus citriodora), lemon eucalyptus oil contains a compound called para-menthane-3,8-diol (PMD).

Like most insect repellents, the PMD in lemon eucalyptus oil makes it harder for mosquitoes to pick up on your skin odor, which leaves you less vulnerable to hungry bugs. Keeping mosquitoes away boosts your defense against diseases like Zika, dengue, and chikungunya, according to the Centers for Disease Control and Prevention (CDC).

In most commercially available insect repellents, lemon eucalyptus oil is processed to intensify its concentration of PMD and, in turn, increase its power and duration as a repellent. The Environmental Protection Agency (EPA) classifies synthetic PMD as a “biochemical pesticide,” which is a type of naturally occurring substance that controls pests by non-toxic mechanisms.

Lemon eucalyptus oil is sometimes used as an alternative to DEET, which is the active ingredient in many popular insect repellents. While DEET is highly effective when it comes to warding off disease-carrying insects, some individuals are concerned about its possible side effects, such as irritation of the eyes and skin.

According to the CDC, EPA-registered products made from synthesized lemon eucalyptus oil appear to provide reasonably long-lasting repellent activity.

The CDC includes EPA-registered products containing synthesized lemon eucalyptus oil and PMD in its list of repellents that can help reduce the bites of disease-carrying mosquitoes. Products containing DEET, picaridin, and IR3535 are also included on the CDC’s list.

It’s important to note the difference between essential oil of lemon eucalyptus and the lemon eucalyptus oil found in many commercially available mosquito repellents. A class of oils used in aromatherapy, essential oils are said to offer a broad range of health benefits (such as reduced stress and anxiety, improvements in sleep, and pain relief) when used appropriately.

Unlike the specially formulated and PMD-rich lemon eucalyptus oil found in many insect repellents, essential oil of lemon eucalyptus rapidly evaporates from your skin. In fact, essential oil of lemon eucalyptus only provides protection from bug bites for about an hour, according to a report published in Malaria Journal in 2011.

The CDC doesn't recommend "pure" essential oil of lemon eucalyptus due to the lack of testing for safety and efficacy.

Due to a lack of studies testing lemon eucalyptus oil’s effects on children, the CDC warns against using the oil on those under three years of age. Pregnant or nursing women and children should consult their primary care provider before using lemon essential oil.

Pure lemon eucalyptus oil shouldn't be applied directly to skin or used in larger amounts than recommended (the oils are absorbed through the skin and using too much can be toxic).

What’s more, certain ingredients in lemon eucalyptus oil products may trigger allergic reactions. For that reason, it’s crucial to perform a patch test prior to using any type of product containing lemon eucalyptus oil. Lemon eucalyptus oil should never be ingested.

Although lemon eucalyptus oil is most commonly used as a mosquito repellent, it’s also said to stave off Lyme disease by preventing deer tick bites. In addition, lemon eucalyptus oil has long been used to soothe muscle spasms and alleviate osteoarthritis pain. However, there’s currently a lack of scientific support for any of these uses of lemon eucalyptus oil.

A number of other plant-based products—including geranium oil and citronella—show promise as natural mosquito repellents. However, given that none of these remedies is known to deliver long-lasting and effective protection, people in high-risk areas for mosquito-borne disease should opt for CDC-recommended repellents.

To stay safe, consult your healthcare provider about the most appropriate repellent for you and apply your repellent whenever you’re outside in areas with known mosquito populations (especially during the hours between dusk and dawn). Carefully follow the instructions on the product label, and make sure to re-apply your lemon eucalyptus oil product as directed if you start getting bitten.