Sure, it can have a nostril-puckering scent, be annoying to apply, and leave your skin shinier than an Oscar statue. But be grateful you live in a world with bug spray. Without it, we’d be much itchier and more disease-prone. As mosquito and tick seasons lengthen due to climate change and increased rainfall, insect repellent is no longer a summertime accessory—it’s a year-round public health essential.
Beyond preventing irritations caused by skeeters and other aerial nibblers, bug spray can help avoid serious illnesses like Zika, Rocky Mountain spotted fever, Lyme disease, and West Nile Virus. These aren’t far-off threats: In summer 2025, New York City issued a health advisory after detecting West Nile virus in more than 180 mosquito pools. “In addition to the annoying bug bites, insect repellent really does help us prevent greater disease,” says dermatologist Bruce Robinson.
But, as you restock your supply, which spray best balances protection with planet-friendliness? The honest answer: It depends. That may sound like a cop-out, but it’s not. The right formula depends on where you’re going, how long you’ll be out, and what you’re trying to protect against. Dinner on the back deck calls for a different solution than a two-day canoe trip through mosquito-heavy swamps.
So we broke down the main types of bug sprays—their pros, cons, environmental impacts, and effectiveness—to help you make a smarter choice this season. A quick reminder, though: No insect repellent is 100% effective, so double up on protection like long-sleeved clothing and be sure to check for ticks if you travel through especially wooded areas.
DEET
Good: Highly effective, long-lasting, recommended by the CDC and World Health Organization
Bad: Non-biodegradable, can harm aquatic ecosystems, greasy, smelly
What is it? DEET (short for N,N-Diethyl-meta-toluamide) is the oldest and most well-studied insect repellent. Developed by the U.S. Army in 1946, it’s incredibly effective against mosquitoes, ticks, and other biting insects. “DEET has gotten a bad rap,” says Robinson. “But it is extremely effective and very well tolerated.” In a recent review in the Journal of American Academy of Dermatology, DEET was deemed the longest-lasting bug repellent available and is the CDC recommendation for avoiding Lyme, West Nile, and Zika.
Robinson notes it’s also considered safe for most people, including pregnant women and children older than two months. The EPA conducted a thorough review of DEET in the late ’90s to confirm its safety. According to the National Institutes of Health, when used as directed, DEET poses little risk to pregnant women. The American Academy of Pediatrics recommends DEET-based sprays with concentrations up to 30% for children.
That said, it’s important to follow the instructions closely to avoid overexposure and keep DEET away from your eyes or any broken skin. It’s also smart to skip combo sunscreen-repellent products: Sunscreens must be re-applied every two hours and this, Robinson points out, could lead to DEET overexposure.
The environmental catch? DEET doesn’t break down easily. It’s been found in surface water, where it may harm aquatic life, and even drinking water. It can also damage plastics, including sunglasses, phone cases, and synthetic fabrics.
Takeaway: For everyday backyard use, you might not need DEET. But if you’re heading into tick-heavy woods or traveling somewhere with malaria or dengue, a 20% to 30% DEET spray is the safest bet—and should last up to 8 hours. Just make sure it doesn’t get on your gear.
Picaridin
Good: Comparable protection to DEET, less toxic to aquatic life, safe for gear, not too greasy
Bad: Still synthetic, not as studied as DEET for avoiding some pathogens
What is it? Picaridin is a synthetic insect repellent modeled after a natural compound in pepper plants. Though newer than DEET—it was developed in the 1980s and approved for use in the U.S. in 2005—it’s recommended by the CDC and WHO for protection against most mosquitoes, ticks, flies, and fleas.
“Picaridin and DEET are pretty comparable,” says Robinson. “Some people think Picaridin may be better tolerated, but both of them are very, very good.” Unlike DEET, Robinson notes that Picaridin, which is referred to as icaridin outside of the U.S., is nearly odorless, non-greasy, and won’t damage plastic, rubber, or synthetic fabrics so it can be sprayed on gear.
A 20% concentration of Picaridin (check repellent labels) and is safe for most people to use, including pregnant individuals and children older than two months.
The environmental catch? Still synthetic, but it breaks down more readily in the environment and is less harmful to aquatic ecosystems than DEET.
Takeaway: If you want broad-spectrum protection without the greasy feel or gear damage, Picaridin is a great choice. It’s ideal for daily use, travel, and outdoor activities—and lasts roughly 6-8 hours per application.
Oil of lemon eucalyptus (OLE)
Good: Plant-derived, biodegradable
Bad: Shorter protection time, not effective against ticks, not safe for kids under 3
What is it? Oil of lemon eucalyptus (OLE) is the most effective plant-based repellent currently available, according to Robinson. Not to be confused with lemon-eucalyptus essential oil, the active ingredient in OLE-based repellents is PMD, a compound derived from the lemon eucalyptus tree. It’s technically a biopesticide and considered non-toxic. “If you want to avoid synthetic chemicals altogether this is your best natural bet,” says Robinson. The only real downsides, he says, are age restriction and duration. “It should not be used in children under 3 years old—and lasts for a maximum of 6 hours.”
Another important caveat: OLE is effective against mosquitoes but not ticks. That’s true of most plant-based repellents, says Robinson. “Very few of them are effective for ticks.” At concentrations around 30%, OLE can protect against mosquitoes for about 4 to 6 hours, making it comparable to lower concentrations of DEET or Picaridin, if not as long-lasting.
The environmental catch? None, really. OLE is plant-derived and biodegradable.
Takeaway: OLE is a solid, natural option for backyard barbecues, park days, or other low-risk activities. Just be sure to reapply every few hours and avoid using it on children under 3.
Essential oils (citronella, cedarwood & more)
Good: Natural, pleasant-smelling, biodegradable
Bad: Very short protection time, limited effectiveness, doesn’t repel ticks.
What is it? These repellents use natural essential oils like citronella, cedarwood, lemongrass, and clove. They’re commonly found in sprays and lotions and in bug-repellent bracelets.
While they may smell nice and prevent mosquitoes from landing on you for a little while, they’re too unreliable for meaningful disease prevention. “These natural repellents are usually not very effective, especially if you’re trying to prevent disease,” says Robinson. Most of these products provide one hour or less of protection and evaporate quickly. For that reason, they’re best reserved for low-risk situations and not recommended when bugs or disease are a major concern.
The environmental catch? Generally safe and biodegradable, some essential oils can trigger allergic reactions or skin sensitivity. It’s always smart to test on a small patch of skin before you put it everywhere.
Takeaway: Use these only when risk is low—like quick errands or casual weekend hangs. Don’t rely on them for serious protection.
Permethrin
Good: Kills mosquitoes and ticks on contact; long-lasting on fabrics
Bad: Not for skin use; synthetic; toxic to cats and aquatic life when wet; requires prep
What is it? Permethrin is a synthetic insecticide derived from chrysanthemum flowers. Unlike DEET or Picaridin, it’s meant for clothing, and gear—not skin. “You can spray it on clothing, camping gear, and other fabric-based items,” says Robinson. “It can last up to a year on the things that you spray it on.” Permethrin-treated clothing can remain effective through about six washes. It kills ticks and mosquitoes on contact—rather than just repelling them—which makes it especially useful in areas where Lyme disease is a big concern.
You should never put permethrin directly on the skin and always apply it in well-ventilated areas. Any articles of clothing or gear sprayed with it need to dry completely before you put them on. Some brands offer clothing pre-treated with Permethrin if you don’t feel comfortable applying the spray yourself.
The environmental catch? When still wet, permethrin is very toxic to cats and aquatic life. Once dry, it’s stable and poses minimal environmental risk.
Takeaway: A great level of protection for adventures that you know will bring you into areas with a lot of mosquitoes and ticks. Pair it with another repellent for full-body protection.
WHEN APPLYING BUG SPRAY: Spray and step away
Whenever you’re applying a DEET-based spray—or another repellent for that matter—a good rule of thumb, per Robinson, is to spray and then step away. That is, apply it and then step back out of the dense mist to avoid inhaling any fumes.
WHEN YOU’VE GOTTEN A MOSQUITO BITE: Put it on ice
What’s the best remedy for a mosquito bite? The quickest (and simplest) relief: ice. “Twenty minutes on, 10 minutes off,” says Robinson. If your bites tend to swell, he recommends taking an oral antihistamine like Benadryl.