The best bug spray for outdoor activities depends on what you’re doing, how long you’ll be outside, and which insects you need to protect against. For most people, a repellent containing 20-30% DEET or 20% picaridin offers the strongest, longest-lasting protection against both mosquitoes and ticks. But those aren’t your only options, and choosing the right one comes down to matching the active ingredient and concentration to your specific activity.
Active Ingredients That Actually Work
The EPA registers four main active ingredients as effective insect repellents: DEET, picaridin, IR3535, and oil of lemon eucalyptus (OLE). Each works by creating a vapor barrier on your skin that makes it harder for biting insects to locate you. The differences come down to how long they last, how they feel on your skin, and what they protect against.
DEET has been the gold standard since the 1950s and remains the most thoroughly tested repellent available. Products range from 5% to 100% concentration, but higher doesn’t mean better protection. It means longer protection. A 10% DEET spray protects for roughly two hours, while 25-30% DEET lasts around five hours. Going above 30% adds minimal extra time and increases the chance of skin irritation or damage to synthetic fabrics and plastics, which DEET is known for.
Picaridin, developed in the 1990s, performs comparably to DEET at similar concentrations but without the greasy feel or material damage. A 20% picaridin spray provides protection for roughly six to eight hours against mosquitoes and up to eight hours against ticks. It’s odorless, won’t dissolve plastic gear or sunglasses, and works well for people who find DEET unpleasant on their skin.
IR3535 is common in lower-concentration formulas and provides moderate protection, typically lasting one to two hours. It’s a good fit for short outings like a backyard barbecue but not ideal for all-day hikes or camping in heavily buggy areas.
Oil of lemon eucalyptus (OLE), also labeled as PMD, is the most effective plant-based option. It provides protection similar to repellents with 15-20% DEET concentrations. One important distinction: OLE is a refined compound, not the same thing as natural lemon eucalyptus essential oil, which has not been tested or approved as an effective repellent. Don’t substitute one for the other. OLE should not be used on children under three years old.
Matching Your Repellent to Your Activity
A quick evening walk and a backcountry camping trip call for very different approaches. For activities under two hours, like a neighborhood jog, a picnic, or yard work, a lower-concentration DEET (10-15%), picaridin, or OLE spray will do the job without needing reapplication.
For longer outings like hiking, fishing, or sports that keep you outside for four or more hours, step up to 20-30% DEET or 20% picaridin. These concentrations cover you through a full day hike without constant reapplication. If you’re sweating heavily or swimming, you’ll need to reapply sooner regardless of concentration, since water and sweat break down the repellent layer.
For tick-heavy environments like tall grass, wooded trails, or leaf litter, pairing a skin-applied repellent with permethrin-treated clothing gives you the strongest two-layer defense. More on that below.
Permethrin: The Clothing-Based Layer
Permethrin isn’t a skin repellent. It’s a treatment you apply to clothing, shoes, and gear that kills ticks, mosquitoes, and other insects on contact. It’s especially valuable for hikers, hunters, and anyone spending extended time in tick territory because it targets insects that crawl across your clothing before reaching your skin.
You spray it onto fabric and let it dry completely before wearing the treated item. Never apply it while wearing the clothing, and always treat items outdoors in a well-ventilated area protected from wind. Once dry, permethrin binds tightly to fabric fibers, meaning very little transfers to your skin during wear. Treated clothing maintains effectiveness through multiple wash cycles, though you should wash treated items separately from the rest of your laundry.
The combination of permethrin on your clothes and a DEET or picaridin repellent on exposed skin is the approach recommended by the CDC for travelers heading into high-risk areas for mosquito-borne and tick-borne diseases.
Spray, Lotion, or Wipes?
Aerosol sprays cover large areas quickly and work well for arms and legs, but they’re easy to overapply or inhale. Hold the can six to eight inches from your skin and spray in a sweeping motion rather than soaking one spot. For your face, spray into your hands first and then rub it on, avoiding your eyes and mouth.
Lotions and pump sprays give you more control over application and tend to waste less product. They’re a better choice for kids, since you can apply a precise amount to each area. Wipes are convenient for travel and touchups but carry the least product per application.
No matter the format, apply repellent only to exposed skin and the outer surface of clothing. There’s no benefit to applying it under your shirt, and doing so just increases skin exposure to chemicals without adding protection.
Using Sunscreen and Bug Spray Together
If you need both sun protection and insect protection, apply sunscreen first and let it absorb, then apply your repellent on top. This layering order matters. DEET-based repellents applied over sunscreen can reduce the sunscreen’s SPF by about one-third, so you may need a higher SPF than you’d normally choose.
Avoid combination products that mix sunscreen and repellent into one formula. Sunscreen needs to be reapplied more frequently and in larger amounts than insect repellent, so bundling them together means you’ll either under-apply your sunscreen or over-apply your repellent. Separate products let you reapply each on its own schedule.
Safety for Kids and Families
DEET, picaridin, and IR3535 are all considered safe for children when applied by an adult according to label directions. For babies under two months old, none of these repellents should be used. Instead, cover infant carriers and strollers with mosquito netting.
For children between two months and three years, DEET and picaridin are options, but OLE is not. Oil of lemon eucalyptus hasn’t been tested enough in that age group to confirm safety. When applying repellent to kids, put it on your own hands first and then rub it onto their skin, keeping it away from their hands (which inevitably end up in their mouths) and any cuts or irritated skin.
What About Citronella and Essential Oils?
Citronella candles, essential oil blends, and wearable repellent bracelets are popular, but their protection is limited. Most essential oil-based repellents provide 30 minutes to two hours of partial protection at best, requiring constant reapplication. Citronella candles reduce mosquito landings in a small radius but don’t come close to eliminating bites, especially in breezy conditions where the scent disperses quickly.
If you prefer a plant-based approach and need real protection, OLE is the only botanically derived ingredient with strong enough evidence to earn EPA registration as an effective repellent. Everything else in the “natural” category is a significant step down in performance.
Quick-Pick Guide by Scenario
- Backyard evenings or short walks: 10-15% DEET, low-concentration picaridin, or OLE spray
- Day hikes or trail running: 20-30% DEET or 20% picaridin, plus permethrin-treated socks and pants for tick protection
- Camping or multi-day trips: 20-30% DEET or 20% picaridin with permethrin-treated clothing and gear
- Fishing or water-adjacent activities: 20% picaridin (less likely to damage gear than DEET), reapplied after getting wet
- Travel to tropical or disease-risk areas: 25-30% DEET or 20% picaridin, permethrin-treated clothing, and mosquito netting for sleeping
- Families with young children: 10-20% DEET or picaridin applied by an adult, no OLE under age three, mosquito netting for infants under two months