DEET has long been the main ingredient in many bug sprays for a reason. It’s considered the best defense against bites from mosquitoes — which can transmit illnesses like malaria, West Nile virus, and Zika — as well as ticks, which can spread Lyme disease and Rocky Mountain spotted fever.
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DEET is a colorless liquid that was developed decades ago by the U.S. Army and has continued to be found effective at keeping bugs away and safe to use on skin, according to facts sheets from the Environmental Protection Agency (EPA) and Oregon State University.
“DEET is the gold standard in preventing insect bites,” says Joshua Zeichner, MD, director of cosmetic and clinical research in the department of dermatology at Mount Sinai Hospital in New York City.
Despite this, some people avoid DEET because they don’t like how it smells or feels on the skin. Note that skin irritation (one of the most common side effects) is often the result of applying the product incorrectly or using too much.
DEET — in very rare cases — has been linked to some side effects, including seizures, uncoordinated movements, agitation, aggressive behavior, and low blood pressure, according to the Centers for Disease Control and Prevention (CDC). But experts, including the EPA and the Cleveland Clinic, among others, widely agree that your chance of serious complications from a disease or problem that might result from an insect bite usually much outweighs the risks associated with DEET itself.
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“DEET has an unusually strong safety record when you consider it has been used for more than 60 years by the public with very few reported incidents of toxicity,” says Michael Merchant, PhD, an urban entomologist at Texas A&M University in Dallas.
But if someone is sensitive to it (if you notice a rash or other issues with use), do consider other options, Dr. Merchant says.
And there are plenty of DEET-free alternatives; the trade-off is they may not work as well as DEET and they may not work against all bugs. Natural options may be gentler on skin, Dr. Zeichner says, “but they often have limited effectiveness.”
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For Natural or DEET-Free Repellants, Make Sure the Ingredients Have Been Found to Be Safe and Effective
“Some 'natural' ingredients are very toxic,” says David Brown, technical advisor for the American Mosquito Control Association in Sacramento, California. Essential oils are natural products (in that they’re not man-made) and are key ingredients for many homemade insect repellant recipes. But they can be very damaging if applied directly to skin (more on that below).
When looking for alternatives to DEET, stick with bug repellent ingredients that have been vetted and recommended by organizations like the CDC and the EPA. Some of the ingredients on this list are compounds derived from plants; others are synthetic.
There’s no blanket benefit to using plant-derived ingredients like oil of lemon eucalyptus (OLE) over products containing ingredients that are synthetic versions of compounds found in nature, Brown adds. Picking the right repellant depends on any irritations or sensitivities to a certain ingredient you might have (you’ll want to avoid those) and what bugs you want to protect yourself against (not all repellants work on all bugs).
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The important thing is that products meet EPA standards, which means they have been tested and found to be safe, Brown says.
The CDC recommends the following ingredients in bug repellents that are derived from plant-based ingredients:
- Picaridin Chemical name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester; it is a synthetic version of a natural insect repellent found in pepper plants. It is found in products including Cutter Advanced, Skin So Soft Bug Guard Plus, and Autan.
- Oil of Lemon Eucalyptus (OLE or PMD) Chemical name: para-menthane-3,8-diol; synthesized OLE is derived from eucalyptus leaves; it is found in products including Repel and Off Botanicals. Note that the CDC recommends looking for OLE as an ingredient in a repellant; oil of lemon eucalyptus essential oil by itself is not recommended as an insect repellant.
- IR3535 Chemical name: 3-[N-butyl-N-acetyl]-aminopropionic acid, ethyl ester; it is a synthetic version of an amino acid. It is found in products including Skin So Soft Bug Guard Plus Expedition and SkinSmart.
- 2-Undecanone Chemical name: methyl nonyl ketone; it is a synthetic version of a compound in rue oil, naturally found in bananas, strawberries, and ginger. It is found in BioUD.
You may need to read labels closely, and look for the chemical names of these ingredients to find them.
Not all products protect against both mosquitoes and ticks, and many repellents that work against both may not protect against both insects for the same amount of time, according to the EPA. Just one product with 2-undercanone that protects against both mosquitos and ticks, for example. But, one application provides five hours of protection against mosquitoes and only two hours of protection against ticks.
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The EPA lists 13 different products with OLE that it has identified as safe and effective for repelling bugs. All of them provide six hours of protection against mosquitoes; but only five of the products offer protection from ticks.
With any bug spray (whether it contains DEET or not), proper application is key to both safety and effectiveness. The No. 1 rule is follow the product’s label for proper use when it comes to how much to apply and how often to reapply.
The CDC and EPA both note the following precautions:
- Don’t spray cuts, wounds, or irritated skin.
- Keep away from hands, eyes, and mouths of young children.
- Don’t spay directly on face — spray hands then rub on face.
- Wash with soap and water when you come inside at the end of the day.
- Don’t spray indoors or in enclosed areas.
Alternatives to Any Type of Bug Spray
If you want to be outdoors without applying bug spray directly to your skin, you still have some good options, says Heather Burrows, MD, PhD, of East Ann Arbor Pediatrics and Michigan Medicine at the University of Michigan in Ann Arbor.
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One good option is treating clothing with permethrin, a pesticide that can kill insects on contact, Dr. Burrows says. Some outdoor suppliers sell clothing pretreated with permethrin, and you can also buy sprays to use on your own clothes.
Apply permethrin to clothing when you’re not wearing it and let it dry completely before you get dressed. Clothes should be treated again after a few washes according to the product instructions; some manufacturers advise that treatment can last for up to six weeks or six washes, but it varies. You should also reapply to shoes or hats that don’t go in the laundry.
Other precautions you can take, Burrows says, include:
- Wearing long-sleeved shirts and long pants
- Using netting to cover your face and neck (or sleeping area)
- Avoiding use of perfumes
- Avoiding standing water, which attracts mosquitoes
- Avoiding spending time outside at dusk when mosquitoes are more active
Why DIY Bug Repellent Is Risky
The biggest risk with making your own bug spray is that it may not protect against serious mosquito-borne illnesses, says Brown.
“Mosquito-borne diseases such as West Nile virus, eastern equine encephalitis (EEE), and other vector-borne diseases are threats every year, so it is much better to apply a repellent that has been tested for both safety and repellency,” Brown says.
The CDC recommends against DIY bug sprays, but if you want to give it a try anyway, you should avoid applying essential oils directly to your skin because this can cause irritation, Zeichner says. Dilute essential oils like citronella, peppermint, or lemon eucalyptus in a carrier like coconut oil before applying it to the skin to avoid irritation — and then stay out of the sun.
“I am cautious about recommending essential oils outdoors, because many lead to phototoxic reactions,” Zeichner says. “This means that the oil may cause a chemical burn in the skin when exposed to ultraviolet light.”