CDC Lists Oil of Lemon Eucalyptus as Comparable to DEET for Mosquitoes

Woman spritzing mosquito repellent on her arm while sitting outside a tent

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Even the CDC recommends this botanical ingredient as comparable to DEET for repelling disease-carrying insects.

Oh, the dichotomies of DEET.

While DEET is the gold standard of insect repellents, it is also a strong synthetic chemical with a tarnished reputation. Known to the chemistry set as N,N-Diethyl-meta-toluamide, DEET was potentially linked to 14 cases of brain damage in the 1980s and 90s, inciting a flood of fear amongst consumers that has yet to recede.

Other reports of ill effects from the ingredients haven’t helped its cause. Scientific American describes one study, among others:

"A study conducted in the late 1980s on Everglades National Park employees to determine the effects of DEET found that a full one-quarter of the subjects studied experienced negative health effects that they blamed on exposure to the chemical. Effects included rashes, skin irritation, numb or burning lips, nausea, headaches, dizziness and difficulty concentrating."

Meanwhile, in 2014 the EPA reported that after an interim review of DEET, they were unable to identify any risks of concern to “human health, non-target species or the environment.” So it's a bit of a mixed bag.

A lot of times we are left weighing relative risks. What’s more important: Using the strongest weapons we can against disease-bearing insects, or staying away from synthetic chemicals that have been associated with health problems?

If you trust the EPA (this writer may question some of their findings, just sayin') then repel to your heart’s content with DEET, following the instructions, of course.

What About a Natural Alternative?

Behold oil of lemon eucalyptus (OLE), the plant-based active ingredient derived from eucalyptus leaves and approved for efficacy by the CDC. The agency notes:

"CDC has evaluated information published in peer-reviewed scientific literature and data available from EPA to identify several types of EPA-registered products that provide repellent activity sufficient to help people reduce the bites of disease-carrying mosquitoes. Products containing the following active ingredients typically provide reasonably long-lasting protection."

They list DEET, picaridin, IR3535, 2-undecanone, and oil of lemon eucalyptus. They describe it as such:

"Oil of lemon eucalyptus (OLE) or PMD (chemical name: para-menthane-3,8-diol), the synthesized version of OLE. Products containing OLE and PMD include, but are not limited to, Repel and Off! Botanicals. This recommendation refers to EPA-registered products containing the active ingredient OLE (or PMD). “Pure” oil of lemon eucalyptus (essential oil not formulated as a repellent) is not recommended; it has not undergone similar, validated testing for safety and efficacy and is not registered with EPA as an insect repellent."

I know that some people shy away from botanicals when they’ve got manmade alternatives to take care of the job, but plants are powerful! There’s a reason why so many of our modern pharmaceuticals are synthesized plant ingredients.

Interestingly, a study published in Malaria Journal (if anyone knows about mosquito protection ...) explains how plants have been used for millennia to repel insects. The use of plant-based oil formulations applied to the skin or clothes were first recorded in writings by ancient Greek, Roman and Indian scholars.

So How Effective Is It?

Consumer Reports looked at plant-oil based repellents and found that one “product in our insect repellent ratings that contained 30 percent oil of lemon eucalyptus (OLE) did well in our tests, warding off mosquitoes and ticks for at least 7 hours.” They add that other products with plant oils – including cedar, cinnamon, citronella, clove, geranium, lemongrass, rosemary, and peppermint – “provided little protection, often failing in our tests within a half-hour.”

(Bonus: That one product that did so well in the Consumer Reports ratings? Repel Plant-Based Lemon Eucalyptus Insect Repellent. But be warned, as one Amazon reviewer put it, "omg does this stuff have a strong smell to it. it not only repels mosquitoes but I'm sure it could work on mother-in-laws, ex's, lawyers, cops, etc. I mean my wife was sent away in tears so imagine what it must do to the bugs. it even says flammable on it?! this stuff is awesome!)

So there you have it. Even the decidedly-not-crunchy CDC finds this botanical alternative to DEET good enough to recommend as one of the five ingredients to use against disease-carrying pests. And Consumer Reports seconds the opinion in their meticulous testing. That's good enough for me. The world already has enough synthetic chemicals being sprayed about, it's time to let the plants do some heavy lifting.

Note: Just because OLE comes from trees, it's still strong stuff. Be sure to read and follow product instructions closely.