Picaridin and IR3535 are quietly retiring DEET from the repellent aisle

By David Ogilvy, Chief Marketing Officer at Mosticare Global | Published 2026-06-11

For seventy years, choosing a mosquito repellent meant choosing how much DEET you could tolerate. In 2026 the buying guides have quietly changed the question. Open a mainstream shopping list this summer and the first names are picaridin and IR3535 — two ingredients most Europeans cannot pronounce and increasingly cannot avoid. The shift is real, the science mostly supports it, and it conceals one limitation that applies to every bottle on the shelf.

DEET still works. Nobody serious disputes that. Developed by the US Army in the 1940s and on civilian shelves since 1957, it remains the most studied repellent in existence and the benchmark every challenger is measured against. What has changed is not DEET's effectiveness. It is the consumer's appetite for it — the greasy feel, the smell, the way it dissolves plastic watch straps and synthetic fabric — and an industry that has finally built credible alternatives to sell into that discomfort.

What is actually rising

Two ingredients are doing most of the displacing.

Picaridin — also called icaridin, the name you will see on European packaging — is the front-runner. It is odourless, does not feel oily, and does not melt your sunglasses. Crucially, it is not a weaker compromise. According to the National Pesticide Information Center, picaridin at a 20% concentration protects against mosquitoes and ticks for 8 to 14 hours; at 10%, for 3.5 to 8 hours. That is competitive with, and at the top end longer than, most DEET formulations. The NPIC also notes that picaridin "appears to be better tolerated on the skin than DEET" and is not associated with the same nervous-system effects — while fairly cautioning that it has not yet accumulated DEET's decades of long-term testing.

IR3535 is the other riser, and it is the European native of the group. Developed by Merck and in use across European repellents since the 1980s, it has a long real-world safety record on the continent. The trade-off is duration: at low concentrations the protection is modest — a 7.5% formulation lasts two hours or less — with meaningfully longer cover only at 10% and above. It is an eye irritant and, undiluted, can irritate skin. In practice it is the gentle, lower-odour option that suits short exposures and sensitive users rather than a day in the field.

Around these two sit the familiar supporting cast: oil of lemon eucalyptus (para-menthane-diol), the one plant-derived repellent with enough evidence to earn a place in official guidance, and DEET itself, now recast as the heavy-duty choice rather than the default.

Who actually decides these claims

Here is the part most shoppers never see. In the United States, none of these duration figures are marketing inventions. The Environmental Protection Agency registers skin-applied repellents, requires manufacturers to submit data proving the product repels mosquitoes or ticks, and must approve any claim about how many hours it lasts. "Protects for up to eight hours" is not a copywriter's flourish; it is a number a regulator signed off on. The European equivalent runs through the Biocidal Products Regulation, which gatekeeps actives before they reach the shelf.

This matters for reading the market honestly. The shift toward picaridin and IR3535 is not a wellness fad floating free of evidence. It is a movement between regulated, tested actives — which is exactly why it is more interesting than the parallel TikTok churn of vanilla extract, coffee grounds and foil balls, none of which a regulator has ever stood behind.

The limit nobody prints on the label

Now the sentence that unites every product in this aisle, the expensive odourless picaridin and the cheap greasy DEET alike: it wears off.

Picaridin's 8-to-14 hours is genuinely long. IR3535's two is genuinely short. But both are countdowns that start the instant you apply them. The entire 2026 repellent market — the whole shelf, every brand, every active ingredient — is a competition over how many hours before the protection lapses and you have to do it again. The consumer shift away from DEET is, at bottom, a shift in feel and odour and skin tolerance. It is not a shift that solves the underlying problem, because the underlying problem is reapplication, and no topical escapes it.

This is worth saying plainly because the marketing never will. A repellent's job is to protect the unprotected hours of an active body — the walk to the restaurant, the touchline, the evening on the terrace until the bottle runs dry. It is a good job and these new actives do it more pleasantly than DEET did. But it is a timer you wear, and the mosquito only needs the window after the timer runs out.

Where the Mosticare lens fits

What consumers are really reaching for, underneath the brand-switching, is protection that does not demand their attention — something that works while they are asleep, distracted, or simply not thinking about mosquitoes. No topical delivers that, because every topical fades and every topical has to be remembered.

The protections that do not fade are physical. A screened window, a treated net over the bed, a tipped-out flowerpot saucer that never let the mosquito breed in the first place — none of these run on a clock, and none care whether the active ingredient of the month is picaridin or a plant oil. They are the complement the repellent aisle cannot sell you: the repellent covers the active hours; the barrier covers the eight you are asleep and reapplying nothing. The 2026 market is moving toward gentler, longer-lasting topicals, and that is genuine progress. It is also still only half of the protection question.

What to watch next

Three things. First, whether picaridin's long-term safety dossier fills in — its main vulnerability against DEET is not performance but the shorter testing record, and another few years of clean data would settle the argument. Second, European labelling: as icaridin and IR3535 dominate continental shelves, watch whether national health bodies start naming them explicitly in seasonal guidance rather than the generic "use a repellent." Third, the economics — Italy's ISS has noted that repellent costs track the oil price, since many formulations and packaging are petroleum-derived, which means a category presented as a lifestyle upgrade is also quietly exposed to the commodities market. The names on the bottle are changing. The clock inside it is not.

What we know

Sources cited

1. NBC Select — "The best insect repellents of 2026," consumer buying guide. https://www.nbcnews.com/select/shopping/best-insect-repellents-rcna341431
2. National Pesticide Information Center (Oregon State University / US EPA) — Picaridin General Fact Sheet. https://npic.orst.edu/factsheets/PicaridinGen.html
3. National Pesticide Information Center — Insect Repellents Fact Sheet. https://npic.orst.edu/factsheets/repellents.html
4. Martin content sweep, 11 June 2026 — item #21 (Italy ISS oil-price-to-repellent-cost observation). intelligence/martin/2026-06-11-content-sweep.md