Before you head into a dengue, zika or malaria zone: the % on the bottle isn't a strength rating — it's a clock. Pick your repellent below and we'll estimate your protection window against mosquitoes (and ticks), then schedule your re-applications for the day.
Protection time isn't one fixed number. Heat, humidity, sweat and swimming all shorten it — so every estimate here is a range, not a promise. Our figures come from EPA repellent guidance, CDC travel-health data, the National Pesticide Information Center, and the landmark Fradin & Day duration study.
More active ingredient buys more hours — up to a ceiling. DEET plateaus around 50%; beyond that you gain almost nothing. So we cap the estimates rather than scaling them forever.
Dengue and zika come from day-biting Aedes mosquitoes; malaria from night-biting Anopheles. Coverage duration matters most when you're exposed all day — reapply on schedule and treat clothing for the night.
It bonds to fabric and kills mosquitoes on contact, so we report its lifespan in laundry cycles: ~5–6 washes for DIY sprays, up to ~70 for factory-treated gear. Treat your wardrobe before you fly — never your skin.
A "5–8 hour" answer reflects real conditions. Treat the low end as your planning number and re-apply before you hit it — especially in tropical heat.
| Active ingredient | Concentration | Mosquitoes | Ticks | Notes |
|---|---|---|---|---|
| Picaridin | ~10% | ~5–8 hrs | ~3–5 hrs | Great for a half-day |
| Picaridin | ~20% | ~8–12 hrs | ~8–12 hrs | Travel-clinic favorite; gear-safe |
| DEET | ~10% | ~2–3 hrs | ~2–3 hrs | Travel minis |
| DEET | ~20–25% | ~4–6 hrs | ~3–5 hrs | CDC everyday range |
| DEET | ~30% | ~5–8 hrs | ~4–6 hrs | Controlled-release reaches the top end |
| DEET | ~50%+ | ~6–8 hrs | ~6–8 hrs | Plateau — no gain above ~50% |
| Oil of Lemon Eucalyptus (PMD) | ~30% | ~4–6 hrs | ~4–6 hrs | Not for children under 3 |
| IR3535 | ~10–20% | ~4–6 hrs | ~4–6 hrs | Varies by product formulation |
| Permethrin (clothing) | 0.5% spray | Kills & repels on contact · lasts ~5–6 washes (DIY) to ~70 washes (factory-treated) | Never on skin; keep from cats until dry | |
Ranges are directional estimates for planning, not guarantees, and are not medical advice. For malaria prophylaxis, vaccines, and destination-specific risk, see a travel medicine clinic before departure.
Picaridin at 20% protects for roughly 8–12 hours — a full day of sightseeing — while 10% formulas last about 5–8 hours. It's the concentration most travel clinics recommend for dengue and zika zones: odorless, dry to the touch, and safe on sunglasses and synthetic gear.
Re-apply when your window runs out, and always after swimming, sweating, or toweling off. 20% picaridin and 30% DEET cover most of a day; 10% travel minis fade in a few hours; plant-based sprays need topping up every 4–6 hours. Enter your day length above for an exact schedule.
Yes — the CDC advises pregnant travelers to Zika-risk areas to use an EPA-registered repellent, and both DEET and picaridin are considered safe when used as directed. Apply it over sunscreen, cover exposed skin, and see a travel medicine clinic before you go.
A DIY permethrin spray lasts about 6 weeks or 5–6 washes; factory-treated garments last around 70 washes. Treat your wardrobe at home ~48 hours before departure. It repels and kills mosquitoes on contact with the fabric — clothing only, never skin, and keep it from cats until dry. Staying stateside instead? Our sister site TickWise runs the same numbers for tick country.