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BugRepellent.Guide

DEET

Active

N,N-Diethyl-meta-toluamide

Does DEET work?

Yes. DEET is the most-studied insect repellent ever made, with six decades of evidence behind it. It confuses the receptors mosquitoes use to find you, and at 25% it delivers roughly 4–5 hours of complete protection. Its real drawbacks are feel, odor, and its appetite for plastics. Safety is not one of them; it is well established at normal use.

When to choose it: Disease-risk travel, dusk in peak season, and anywhere bites are non-negotiable. For most users, 20–30% is the sweet spot.

The most widely used synthetic active ingredient in insect repellents. Effective against mosquitoes, ticks, and many biting flies.

How it works

Interferes with insect olfactory receptors, masking cues that attract mosquitoes to human skin and breath.

The evidence

Decades of field and laboratory studies support efficacy; concentration correlates with duration of protection.

Mosquito protection by concentration: DEET

7%
1–2 h
15%
3–4 h
25%
5–6 h
40%
6–7 h
98%
6–8 h
0h2h4h6h8h10h12h

Complete protection time (dark = lower bound, light = upper bound) on the same 12 h scale used across the site. Modeled from published dose-response data in our research library.

Common misconceptions

Myth: “Higher-percentage DEET repels more strongly.”

Reality: Concentration changes how long protection lasts, not how hard it repels. 98% DEET is not 'stronger' than 30%; it just keeps working for a couple more hours.

Myth: “DEET is dangerous.”

Reality: Decades of surveillance and EPA re-review have found DEET safe when used as directed, including for children over 2 months. Adverse events are rare and overwhelmingly tied to gross misuse.

Myth: “DEET kills mosquitoes.”

Reality: DEET doesn't kill anything. It scrambles the olfactory cues mosquitoes use to land on you. They're still there; they just can't commit to biting.

Regulatory notes

EPA SRS-registered active. Not a FIFRA 25(b) minimum risk active. Concentration limits vary by product type.

Safety notes

Generally safe when used as directed. Avoid over-application on children; wash off after returning indoors.

The best products built on it

Ben's

97

Ben's 100 Tick and Insect Repellent Pump Spray

100%

OFF!

94

OFF! Deep Woods Insect Repellent VIII

25%

Ben's

94

Ben's 30 Tick & Insect Repellent Eco-Spray

30%

All products using it

Frequently asked questions

How long does DEET last?

Roughly 1–2 hours at 7%, 3–4 hours at 15%, 4–5 hours at 25%, and 6–8 hours at the highest concentrations. Those figures come from complete-protection-time studies, with partial protection extending beyond those windows.

Is DEET safe for kids?

The American Academy of Pediatrics considers up to 30% DEET appropriate for children older than 2 months, applied by an adult and washed off afterward.

Why does DEET melt plastic?

DEET is a strong solvent for certain synthetics: watch faces, sunglasses, and some technical fabrics can cloud or soften on contact. Picaridin offers similar protection without that problem.