What Is Oil of Lemon Eucalyptus?

Plant-based mosquito repellents have been around since the 1950s. Research has found that one plant-based repellent deemed effective against mosquitoes is oil of lemon eucalyptus (OLE) extract.  

What Is Oil of Lemon Eucalyptus Extract?

OLE extract—known as p-menthane-3,8-diol (PMD)—derives from the leaves of lemon eucalyptus trees and is chemically synthesized. Usually, OLE comes as a spray but is also found in lotions. OLE works as a repellent against biting flies and gnats. In 2000, the Environmental Protection Agency approved OLE as an insecticide.

Then, following two studies led by Stacy Rodriguez, a former laboratory manager of the Molecular Vector Physiology Lab at New Mexico State University, the ingredient earned its mosquito-repelling stripes.

OLE extract is not the same as lemon eucalyptus essential oil. The essential oil is pure oil, unlike the repellent. Somewhat confusingly, the essential oil is often marketed as being a mosquito repellent. Though, experts do not advise people to use the essential oil as a repellent. There is no research on its safety or effectiveness.

What Has Research Found?

In 2015, Rodriguez and a team of researchers examined eight commercially available repellents, two fragrances, and a vitamin B patch. When applied to hands, the researchers noted if the formulas repelled or attracted disease-carrying mosquitoes Aedes albopictus and Aedes aegypti.  

The researchers found that Cutter Lemon Eucalyptus Insect Repellent, a plant-based spray containing OLE, was the only DEET-free formula to deliver strong, long-lasting results.

Then, in 2017, Rodriguez and a team of researchers examined how effectively wearable repellents—like bracelets—DEET sprays, and OLE sprays protect against Aedes aegypti. That species of mosquito is one of the most likely culprits of Zika. Once more, the researchers found that the Cutter Lemon Eucalyptus Insect Repellent was effective.

How Does Oil of Lemon Eucalyptus Compare to Other Repellents?

As a mosquito repellent, OLE has been found to be just as effective as DEET. Research has found that OLE worked better than DEET as tick protection.

Still, you do not need to shy away from synthetic repellents like DEET and picaridin if you are using OLE and looking for a science-backed method of repelling mosquitoes. People have used DEET for decades.

Some evidence suggests that DEET protects against ticks that spread Lyme disease in addition to mosquitoes and ticks carrying diseases like:

• Malaria
• West Nile 
• Zika 

Research has found that OLE is slightly more effective than picaridin in protecting against malaria. Though, OLE shares similar effectiveness against mosquitoes carrying arboviruses like the ones that lead to West Nile.

Of note, OLE is only effective for five hours at a time at 20% strength formulations. DEET and picaridin offer higher protection levels at the same or higher strength formulations.

Potential Risks of Oil of Lemon Eucalyptus Extract

Generally, OLE is safe for use. OLE falls in Toxicity Category 4 for oral and skin exposure based on the Office Pesticide Program categories. In other words, OLE is barely nontoxic. 

In contrast, OLE is a Toxicity Category 2 for eye exposure and can irritate the eyes. Children under 3 should not use OLE extract because it can irritate their eyes.

How To Find Oil of Lemon Eucalyptus Extract

Mosquito repellents that contain OLE extract are relatively affordable. You can purchase OLE online, but make sure you read the labels carefully.

Look for a product that lists "oil of lemon eucalyptus" as the active ingredient, like the Cutter Lemon Eucalyptus Insect Repellent. You can also try Repel Lemon Eucalyptus Natural Insect Repellent. Both can deliver up to six hours of protection. Remember to reapply after that time.

A Quick Review

OLE is a synthetic mosquito repellent. OLE is not the same as lemon eucalyptus oil, which research has not deemed an effective repellent. Research has found that OLE is as effective as other mosquito repellents like DEET.