Do 'Natural' Insect Repellents Work?
Not all products are created equal. Here's what you need to know.
It’s a simple question, one that CR readers frequently ask us: Do natural insect repellents work?
The answer, however, is a bit complicated. Two of the three active ingredients that have regularly earned recommended status in our insect repellent ratings—picaridin and oil of lemon eucalyptus, or OLE—are derived from plants or synthesized to mimic chemicals in plants. But several other plant-based chemicals, including lemongrass and soybean oil, typically end up at the very bottom of our ratings.
The Natural Products Association, a trade group, has defended those low-scoring insect repellents by pointing out that there’s variation in the effectiveness of all repellents, natural and synthetic.
Oil of Lemon Eucalyptus (OLE)
What is it? It’s important not to confuse this product with lemon eucalyptus oil. The names are very similar, but the two chemicals are quite different. OLE is an oil extracted from the gum eucalyptus tree (native to Australia); the actual extracted chemical is called PMD and has demonstrated efficacy as an insect repellent.
Lemon eucalyptus oil, by contrast, is distilled from the leaves and twigs of the lemon eucalyptus tree. The distilled product contains several botanical substances, including citronella and a very low and variable amount of PMD.
Does it work? In our insect repellent testing, two products, Repel Lemon Eucalyptus Insect Repellent and Natrapel Lemon Eucalyptus Insect Repellent, earned our recommendation. However, neither of these is labeled for use against ticks. If you know you’ll potentially be exposed to ticks, you may want to choose a repellent that contains deet or picaridin, two active ingredients in our other recommended repellents. (Digital and All-Access members can see our ratings for full details.)
Is it safe? The EPA classifies PMD as a biopesticide, which means it’s subject to more safety testing than botanicals (see below), including lemon eucalyptus oil, but less testing than synthetic chemicals like deet and picaridin. Both federal regulators and our experts agree that OLE is relatively safe.
OLE isn’t quite as well studied as some other repellent ingredients. But the research we do have suggests that any adverse reactions are limited to eye and skin irritation. OLE shouldn’t be used on children younger than 3, in part because research is lacking on OLE in young children (deet and picaridin are both considered safe to use on children older than 2 months).
What is it? Picaridin is a chemical synthesized (meaning made in a lab) to mimic a compound found in pepper plants. It’s been available as an insect repellent in the U.S. since 2005.
Does it work? Sprays containing 20 percent picaridin have performed well in our tests, but one wipe and one lotion made with that concentration scored poorly. We don’t know why picaridin appears to perform better as a spray, says Joan Muratore, who heads insect repellent testing at CR, but skipping the wipe or lotion formulations of this ingredient is probably wise. Although one spray with 10 percent picaridin earned our recommendation, another one didn’t, so we suggest sticking to sprays with a concentration of 20 percent.
Is it safe? Picaridin may cause eye and skin irritation, but this is probably rare. In one analysis of poison control calls related to insect repellents, picaridin caused only a few problems, and almost none of them required a visit to a doctor’s office or emergency room.
What are they? Botanical repellents, which often have "natural" on product labeling, can include any number of plant-based chemicals. Some common ones are lemon grass, citronella, peppermint, geraniol, soybean, and rosemary. Those ingredients can be oils extracted directly from plants or synthetic chemicals that exactly replicate their natural counterparts.
Do they work? These products aren’t registered with the EPA. Because the agency doesn’t consider the chemicals they contain to pose any serious safety risks, it doesn’t bother to evaluate them. As a result, the companies that make botanical products aren’t required to prove to federal regulators that they actually work. And CR's testing has repeatedly found that they don’t work well.
Are they safe? Yes and no. The chemicals in these products are unlikely to cause you any serious harm themselves, though they do contain known allergens, often at much higher concentrations than other natural products. But by using an unregistered botanical repellent, you expose yourself to the risk of serious mosquito- and tick-borne diseases, some of which can be life-threatening.
Editor's note: This article has been updated with new information.
Jeneen Interlandi and Catherine Roberts contributed reporting.