DEET vs. Picaridin: which repellent is actually better?

Both are EPA-registered, both work, and both are available at any drug store. The differences are real but narrow — and mostly come down to feel, duration, and what you're trying to repel.

The short answer

DEET is the gold standard — the most studied repellent on the planet, effective against mosquitoes, ticks, flies, and more, with a 50-year track record of safety when used as directed. Picaridin (also sold as Icaridin outside the US) is newer, odorless, doesn't feel oily, won't damage plastics or synthetics, and performs essentially the same against mosquitoes — often with longer protection at equivalent concentrations. For most people doing yard work, hiking, or sitting on a patio, either is a correct choice. The main reason to pick one over the other is feel.

How repellents actually work

Neither DEET nor Picaridin kills mosquitoes. They work by interfering with the insects' ability to detect you. Mosquitoes locate hosts through a combination of CO₂ from your breath, heat, and specific odor compounds — including lactic acid and other volatiles your skin releases. DEET and Picaridin are volatile compounds that mask or block those attractant signals, making you effectively invisible to a mosquito's chemoreceptors.

The older theory was that mosquitoes "smelled" DEET and were repelled by it. More recent research suggests DEET actually blocks the olfactory receptors mosquitoes use to detect human odors in the first place. Picaridin appears to work through similar receptor interference, which is why their real-world effectiveness is so comparable.

Concentration matters: higher percentage means longer duration, not stronger protection per se. A 10% DEET spray gives you about two hours of coverage; 30% gives closer to six. The same principle applies to Picaridin.

DEET was developed by the US Army in 1944 and approved for civilian use in 1957. It is the most extensively tested insect repellent in existence — more than 40 years of CDC and EPA review, hundreds of studies. For that reason, it's still the first repellent the CDC recommends for preventing mosquito-borne illness when traveling to high-risk areas.

The complaints are real: DEET has a strong chemical smell that some people find unpleasant, leaves a greasy residue on skin, and will literally dissolve certain plastics, synthetic fabrics, and watch bands if it gets on them. It's not dangerous on those materials — it just ruins them. Use it on skin and clothing; keep it away from gear.

Safety concerns around DEET have been studied extensively. At concentrations of 30% and below — which covers nearly all consumer products — the CDC and AAP consider it safe for adults and children over two months. The rare serious adverse events reported over the decades have almost all involved ingestion or massive, repeated exposure far outside normal use.

Picaridin was developed in the 1980s by Bayer, modeled on piperine — the compound that makes black pepper spicy. It was widely used in Europe and Australia for years before the EPA registered it for US use in 2005. The World Health Organization recommends it alongside DEET as a top-tier repellent.

The practical advantage over DEET is texture and smell. Picaridin is odorless, feels like a light lotion, and doesn't damage synthetics, plastics, or watch straps. For people who've been put off by DEET's greasiness or smell, Picaridin is frequently described as revelatory — same protection, none of the sensory downsides. It also appears to be slightly more effective against flies and midges than DEET at equivalent concentrations.

Its main limitation is ticks. For tick protection in high-risk areas (hiking, tall grass, woods), DEET has a larger and longer evidence base. Picaridin works on ticks too — particularly at 20%+ concentrations — but most Lyme-endemic-area guidance still defaults to DEET or Permethrin for tick-heavy environments.

Side-by-side

What about the other options?

Two other EPA-registered repellents are worth knowing about:

Oil of Lemon Eucalyptus (OLE) — not the essential oil, which doesn't work, but the refined extract (active ingredient: PMD). The CDC and EPA both recognize it as an effective plant-based repellent at concentrations of 30–40%. Duration is shorter than DEET or Picaridin, and it's not recommended for children under three. Brands include Repel Lemon Eucalyptus and Coleman Botanicals.

IR3535 — widely used in Europe, less common in the US. Works primarily on mosquitoes and biting flies. Shorter duration than DEET at equivalent concentration; usually found in sunscreen-repellent combo products.

Permethrin is in a separate category — it's a contact insecticide, not a skin repellent. You apply it to clothing, tents, and gear (not skin), where it kills or repels insects on contact and remains active through multiple washes. For serious outdoor use, treating clothing with Permethrin and using DEET or Picaridin on skin together is the most complete coverage you can get.

How to apply it correctly

Most repellent failures come from application, not product. A few rules that matter:

Apply to all exposed skin — don't leave gaps. Mosquitoes will find the inch of ankle between your sock and your pants. Apply to hands and then rub on your face; never spray directly toward your face. If you're using sunscreen, apply sunscreen first and let it absorb, then apply repellent. Combination sunscreen-repellent products are less effective because sunscreen needs reapplication every two hours but repellent does not, and re-applying repellent too frequently increases absorption.

Reapply after sweating heavily or swimming. Wash repellent off with soap and water when you come inside — there's no reason to have it on your skin once you're no longer at risk of bites.

For kids: apply to your own hands first, then apply to the child. Avoid hands, around eyes, and on cuts or irritated skin. The AAP recommends no repellents on infants under two months old regardless of product.

Sources

• Centers for Disease Control and Prevention. Preventing mosquito bites — repellent guidance.
• EPA. Find the repellent that's right for you — EPA registered active ingredients search tool.
• American Academy of Pediatrics. Insect repellents for children.
• Fradin, M. S., & Day, J. F. (2002). Comparative efficacy of insect repellents against mosquito bites. New England Journal of Medicine, 347(1), 13–18.
• World Health Organization. Guidelines for malaria — personal protection (Picaridin / Icaridin recommendation).
• Hallem, E. A., et al. (2004). Olfaction: mosquito receptor for human-sweat odorant. Nature, 427, 212–213. (DEET receptor-interference mechanism.)

Not medical advice. This article draws on EPA and CDC guidance, peer-reviewed research, and product labeling. If you have questions about repellents during pregnancy, for a young infant, or if you have a specific health condition, check with your doctor or pharmacist.

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