Insect Repellent for Travelers: DEET vs Picaridin vs Permethrin (A Physician's Guide)

For most international travel, the right approach is two products working together: a skin repellent containing 20 to 30 percent DEET or 20 percent picaridin, applied to exposed skin, plus permethrin-treated clothing worn over the top. This combination has been studied repeatedly by the CDC and the Department of Defense and reduces mosquito bites by more than 90 percent in field conditions. In my emergency department practice, the returning travelers who get malaria, dengue, or rickettsial infections almost never used a real repellent. They used a wristband, a citronella candle, or nothing at all. The product on the shelf at the drugstore matters less than choosing an EPA-registered active ingredient, applying enough of it, and reapplying on schedule. This guide walks through what works, what does not, and how to pack for the destinations that actually drive travel-related vector-borne disease.

Why insect repellent is non-negotiable on most international trips

Mosquitoes are the deadliest animal on the planet, responsible for roughly 725,000 deaths a year according to the World Health Organization, with most of that burden from malaria. Repellent is the first layer of personal protection, and it is the one layer entirely under your control.

Vaccines exist for some diseases (yellow fever, Japanese encephalitis, tick-borne encephalitis, dengue in select circumstances), and chemoprophylaxis exists for malaria. Repellent is what prevents the bite in the first place, which means it is also the only intervention that meaningfully reduces dengue, Zika, and chikungunya risk, because there is no widely available vaccine or pill for those in the US traveler population. As an ER physician who has worked up travelers with sudden fevers after a Caribbean honeymoon or a Southeast Asia backpacking trip, I would put repellent in the same category as a seatbelt. It is unglamorous, easy to forget, and the thing you wish you had used.

The four active ingredients the CDC actually endorses

The CDC and EPA recognize four active ingredients with enough evidence to recommend for travel: DEET, picaridin, IR3535, and oil of lemon eucalyptus (OLE, also sold as PMD). Everything else, including citronella, geraniol, "essential oil blends," ultrasonic devices, vitamin B1, and wristbands, has either failed in head-to-head testing or never been studied at a meaningful level. If a product does not list one of those four ingredients on the label, it does not belong in a travel pack.

DEET (N,N-diethyl-meta-toluamide)

DEET has been in continuous use since 1957 and is the most studied repellent in the world. The EPA has reviewed it three times for safety and concluded that, when used as directed, it does not present a health concern to the general population, including pregnant women and children over two months.

Concentration matters but only up to a point. Field studies show DEET provides linear duration of protection up to about 30 percent, then plateaus. A 30 percent formulation gives roughly five to six hours of protection against most mosquitoes. Going above 30 percent does not protect you more, it just protects you longer, and most modern formulations cap out at 30 to 40 percent for that reason. The American Academy of Pediatrics specifically advises against DEET concentrations above 30 percent in children.

DEET can damage plastics, synthetic fabrics, watch crystals, and the coatings on some sunglasses. Apply it carefully and wash your hands before handling electronics.

Picaridin (also called icaridin or KBR 3023)

Picaridin is a synthetic compound modeled on a molecule in pepper plants. It has been the European standard for years and was approved in the US in 2005. In head-to-head trials against mosquitoes, 20 percent picaridin performs comparably to 20 to 30 percent DEET and provides eight to ten hours of protection. Against ticks, picaridin matches DEET. It does not damage plastics or fabrics, has no odor, and feels closer to a light lotion than a chemical spray. For travelers who hate the feel of DEET, this is the upgrade. Sawyer 20% picaridin lotion is the formulation I recommend most often to patients.

IR3535

IR3535 has been used in Europe since 1975 and is the active ingredient in many Avon Skin So Soft "Bug Guard" products. It is gentle on skin and safe across age groups but provides shorter protection windows than DEET or picaridin at equivalent concentrations. Reasonable choice for low-risk destinations or for travelers with sensitive skin. Not the right tool for a Tanzania safari.

Oil of lemon eucalyptus (OLE) and PMD

OLE, derived from the lemon eucalyptus tree and refined into the active ingredient p-menthane-3,8-diol (PMD), is the only plant-based repellent the CDC recognizes. A 30 percent OLE formulation can match low-concentration DEET in duration. Two important caveats: the CDC and EPA both restrict OLE and PMD to ages three and older, and the unrefined "pure essential oil" version is not the same product and has not been tested as a repellent. Look specifically for "oil of lemon eucalyptus" or "p-menthane-3,8-diol" on the EPA-registered label.

Permethrin: the product you spray on clothes, not skin

Permethrin is a different category. It is an insecticide, not a repellent, and it goes on clothing, gear, and tent fabric, never on skin. Permethrin kills mosquitoes and ticks on contact rather than just driving them away. It binds to fabric fibers and survives roughly six washes when applied at the consumer concentration (0.5 percent), or about 70 washes if you buy pre-treated clothing.

The US military issues permethrin-treated uniforms for a reason: field studies of permethrin-treated military uniforms have shown bite reductions exceeding 90 percent compared with untreated controls. Insect Shield is the commercial version civilians can buy, and Sawyer sells the spray-on solution to treat your own clothes at home.

In my clinical opinion, every traveler going to a high-risk malaria, dengue, or tick zone should treat at least one full outfit (long pants, long-sleeve shirt, socks) plus a hat before they leave. Spray it, hang it outdoors, let it dry for two hours, and pack it. That single step is one of the highest-yield travel health investments you can make.

What concentration to actually buy

Skip anything below the lower bound of those ranges. A 7 percent DEET wipe from a hotel gift shop is not adequate for a region with active dengue or malaria transmission.

How to apply repellent so it actually works

Pop the cap on a $14 bottle of picaridin and you have done about half the job. The other half is technique.

Apply sunscreen first, let it absorb for 15 to 20 minutes, then apply repellent on top. The CDC does not recommend combination sunscreen-repellent products because sunscreen needs to be reapplied every two hours and repellent generally does not, and reapplying repellent every two hours is more chemical exposure than you want.

Spray into your hands, then rub onto exposed skin. Avoid the eyes, mouth, and any broken skin. For children, an adult should apply it for them, never letting kids spray their own faces. Wash your hands after applying, especially before eating.

Cover every patch of exposed skin. Aedes mosquitoes, the species responsible for dengue, Zika, and chikungunya, are day-biting and have a particular preference for ankles. If your pant leg rides up, that ankle skin needs to have repellent on it. The bite that gives you dengue does not announce itself.

Reapply on the schedule the product specifies, and reapply earlier if you have been swimming, sweating heavily, or toweling off. After dark, when malaria-transmitting Anopheles mosquitoes are most active, repellent on exposed skin plus permethrin-treated long sleeves and pants is the standard.

Pregnancy, breastfeeding, infants, and kids

Mosquito-borne diseases are more dangerous in pregnancy than the repellents that prevent them. Zika in particular can cause severe birth defects, and malaria in pregnancy carries substantially elevated risk of both maternal and fetal complications. The CDC explicitly states that DEET, picaridin, IR3535, and OLE (for the mother, not the child) can all be used in pregnancy and during breastfeeding when used according to the label.

For infants under two months: no chemical repellent. Use mosquito netting over the stroller and carrier instead.

For children two months and older: DEET up to 30 percent, picaridin up to 20 percent, or IR3535 are all appropriate. OLE and PMD are restricted to ages three and older. Apply repellent to your own hands first, then wipe onto the child's skin, avoiding hands (they go in mouths) and face.

What does not work

If a product is not on the EPA-registered list, it is almost certainly not effective at travel-relevant levels of exposure. The Consumer Reports and journal-published data are consistent on this:

• Wristbands, patches, and clip-on devices. No measurable reduction in bites in field trials.
• Ultrasonic apps and devices. A Cochrane systematic review found no preventive effect against malaria.
• Citronella candles and essential oil sprays. Short-lived and inconsistent. A candle creates a small zone of partial protection in still air. The mosquito biting your ankle does not care.
• Vitamin B1, garlic supplements, "bug-repelling" foods. Studied repeatedly. No effect.

If your strategy for a trip to Costa Rica or Kenya is a citronella bracelet, you are unprotected.

Where high-risk applies: destination quick reference

The repellent strategy scales with the disease pressure at your destination. A weekend in London does not need permethrin-treated clothing. A two-week safari in Tanzania absolutely does.

• Sub-Saharan Africa (Kenya, Tanzania, Uganda, Rwanda, Ghana, Ethiopia, Madagascar, Botswana). Malaria, yellow fever zones, and tick-borne rickettsial disease. Use 20 to 30 percent DEET or 20 percent picaridin plus permethrin-treated clothing and a permethrin-treated hat. See our Kenya travel health guide and Tanzania guide.
• Southeast Asia (Thailand, Vietnam, Cambodia, Indonesia, Philippines). Dengue is endemic and surging. Japanese encephalitis in rural rice-growing areas. Permethrin plus daily picaridin or DEET is the standard. Aedes mosquitoes bite during the day, so do not save repellent for sundown.
• South Asia (India, Sri Lanka, Nepal). High traveler's diarrhea risk overlaps with dengue, malaria in rural areas, and Japanese encephalitis. Repellent strategy mirrors Southeast Asia. See our India guide.
• Central and South America (Peru Amazon, Brazil, Colombia, Ecuador, Costa Rica). Dengue is widespread and Aedes mosquitoes are day-biting. The Amazon basin adds malaria and yellow fever. The Caribbean coast adds chikungunya. Permethrin plus DEET or picaridin daily.
• Caribbean (Dominican Republic, Jamaica, Bahamas, Puerto Rico, Aruba). Dengue is now considered endemic across most of the Caribbean. The CDC issued elevated dengue notices for multiple islands in 2024 and 2025. Skin repellent during daylight is the priority.
• Europe and developed urban destinations. Lower risk overall, but tick-borne encephalitis in central and eastern Europe (April to November), Lyme across most of Europe, and an expanding zone of West Nile and dengue in southern Europe. Picaridin or DEET on exposed skin during outdoor activity, permethrin if you are hiking.

Field bag: what I actually pack

For a high-risk trip (Africa safari, Amazon, Southeast Asia rural):

• One bottle of 20 percent picaridin spray for daily skin application.
• One bottle of 30 percent DEET as backup for the worst dusk hours.
• Pre-treated permethrin clothing (Insect Shield) or DIY permethrin-treated long pants, long-sleeve shirt, socks, and hat.
• A pop-up mosquito net for accommodations without window screens.
• A small permethrin-treated bandana for face coverage during evening outdoor meals.

For an urban or short trip: one bottle of 20 percent picaridin in the toiletry kit.

Repellent fits into a layered prevention plan

Repellent is foundational, but for high-risk destinations it is one layer in a stack. The other layers depend on the country:

• Malaria prevention pills (Malarone, doxycycline, or Tafenoquine) for travel to malaria-endemic regions. Repellent reduces bites; antimalarials reduce the probability that a bite that does get through becomes malaria. You need both.
• Vaccines for yellow fever, Japanese encephalitis, typhoid, hepatitis A, and others depending on destination.
• Behavioral modifications. Stay indoors during peak biting times when possible, sleep under a treated net, use air conditioning when available.

Get your malaria prevention prescription called in to your local pharmacy before you leave so it is waiting when you need it. For required and recommended travel vaccines, book your appointment at a partner pharmacy through Wandr. Combining the right repellent with the right pre-trip prescriptions is what actually keeps US travelers out of the ER after they get home.

FAQ

Is DEET safe for kids and pregnant women?

Yes. The CDC and American Academy of Pediatrics both endorse DEET up to 30 percent for children over two months and during pregnancy and breastfeeding. The risk of Zika, malaria, or dengue is substantially higher than any risk from properly applied DEET. For infants under two months, use physical barriers like fine mesh netting on strollers instead.

What concentration of DEET do I actually need?

For most travel, 20 to 30 percent DEET is the sweet spot. Concentrations above 30 percent give you more hours of protection but no greater intensity of protection, and the AAP recommends staying at or below 30 percent for children. A 7 to 10 percent DEET product from a hotel gift shop is not enough for a malaria or dengue zone.

Is picaridin better than DEET?

For most travelers, picaridin at 20 percent is the better all-around choice. It matches DEET on protection time, does not damage plastics or fabrics, has minimal odor, and feels lighter on skin. DEET still has the edge in extreme jungle or swamp conditions where you want the longest-studied molecule on your side.

Do natural or essential oil repellents work?

Most do not. The only plant-derived repellent the CDC recognizes is oil of lemon eucalyptus (OLE) or its refined form PMD, and only at 30 percent and only for ages three and up. Citronella, peppermint, lavender, geraniol, and "essential oil blends" provide short, inconsistent protection in field trials. They are not appropriate for travel to malaria, dengue, or Zika zones.

Can I put sunscreen and repellent on at the same time?

Apply sunscreen first, let it absorb for 15 to 20 minutes, then apply repellent on top. The CDC advises against combination sunscreen-repellent products because the reapplication schedules conflict: sunscreen needs reapplication every two hours and repellent does not.

Does permethrin really work, or is it overkill?

Permethrin works. Field studies of permethrin-treated military uniforms have demonstrated bite reductions exceeding 90 percent compared with untreated uniforms. For travel to high-risk areas like sub-Saharan Africa, the Amazon, or rural Southeast Asia, permethrin-treated clothing is not overkill, it is the standard of care.

Will repellent protect me from ticks too?

DEET (20 percent or higher) and picaridin (20 percent) both repel ticks effectively when applied to exposed skin. For ticks specifically, permethrin-treated clothing is more important than skin repellent because ticks crawl up from the ground. Wear treated socks and tucked-in long pants if you are hiking in Lyme or tick-borne encephalitis zones.

How often do I need to reapply?

Follow the product label. As a general rule, 20 percent picaridin lasts 8 to 10 hours, 30 percent DEET lasts 5 to 6 hours, IR3535 and OLE last 4 to 6 hours. Reapply earlier if you have been swimming, sweating heavily, or toweling off.

Medical disclaimer

This article is for educational purposes and does not substitute for individualized medical advice. Talk to a clinician before your trip, especially if you are pregnant, breastfeeding, traveling with infants, or have skin conditions or chemical sensitivities. Wandr Health clinicians can review your itinerary and call any needed prescriptions in to your local pharmacy, and Wandr can book your travel vaccine appointments at a partner pharmacy near you.

Sources

• Centers for Disease Control and Prevention. Avoid Bug Bites. CDC Yellow Book and Traveler's Health: https://wwwnc.cdc.gov/travel/page/avoid-bug-bites
• Environmental Protection Agency. Skin-Applied Repellent Ingredients: https://www.epa.gov/insect-repellents/skin-applied-repellent-ingredients
• World Health Organization. Vector-Borne Diseases Fact Sheet: https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases
• Eamsila C, et al. Evaluation of permethrin-treated military uniforms for personal protection against malaria. Journal of the American Mosquito Control Association.
• American Academy of Pediatrics. Choosing an Insect Repellent for Your Child: https://www.healthychildren.org
• Centers for Disease Control and Prevention. Zika Virus and Pregnancy: https://www.cdc.gov/zika

Related Wandr resources

• Do I Need Malaria Pills for My Trip? A Physician's Decision Guide
• Travel Health Guide: Kenya
• Travel Health Guide: Peru
• Dengue Fever in Travelers: A Physician's Complete Guide
• The Ultimate Pre-Trip Health Checklist