3 Jul 20266 min read

Which? lab-tested 12 mosquito repellents. A four-pound supermarket spray beat a twenty-pound "natural" one.

Which? lab-tested 12 mosquito repellents on 1 July 2026. A £4 supermarket DEET-based spray lasted longest; a £20 'natural' product offered essentially no protection at the two-hour mark. The result confirms what the 60 Millions de Consommateurs and Consumer Reports tests in the same week also found: the active-ingredient concentration and re-application interval are the meaningful performance levers, and the price-or-label signal is not.

Mosticare Editorial
Last updated · 3 Jul 2026
woman in white long sleeve shirt using white and black sewing machine
“woman in white long sleeve shirt using white and black sewing machine” — Photo by DIANA HAUAN on Unsplash

There is a small, stubborn arithmetic to the UK consumer market for anti-mosquito sprays. The product with the longest protection time in the 2026 Which? test was a £4 supermarket own-brand DEET-based spray. The product with the shortest protection time was a £20 "natural" formulation that offered essentially no protection at the two-hour mark. The price ratio was five to one. The performance ratio was effectively infinity to one, in the direction the Which? test was not expecting to confirm.

Which?, the UK's largest consumer group, published the 2026 test on 1 July 2026. The result landed at the same point as the 60 Millions de Consommateurs test published the week before in France, and the same point as Consumer Reports' 2026 roundup in the US. The structural fact this cycle is that three independent consumer labs, in three regulatory environments, on three different product mixes, landed on the same answer. The answer is that the active-ingredient concentration and the re-application interval are the meaningful performance levers, and the marketing label is not.

What we know

  • Which? tested 12 mosquito repellents in lab conditions, publishing the results on 1 July 2026. A £4 supermarket DEET-based spray lasted longest; a £20 "natural" product offered essentially no protection at the two-hour mark.
  • The result prompted substantial UK media reaction, including coverage in The Telegraph, The Guardian, and the Daily Mail.
  • 60 Millions de Consommateurs published the parallel French test on 24 June 2026, with the same conclusion: few genuine innovations in the repellent category, widely uneven effectiveness, no clear "miracle" product.
  • Consumer Reports' 2026 lab-tested repellent roundup covered lotions, sprays, wipes and plant-based formulations using live mosquitoes. The result list is now the de facto US consumer reference.
  • The three tests are independent in methodology. They do not coordinate, and they do not share test data. The shared conclusion is the structural fact.

The structural fact about the £4 spray

The £4 supermarket spray is not a miracle product. It is a DEET-based formulation at the concentration listed on the can, applied at the recommended interval. The product does what the active ingredient says it does, at the concentration listed, for the duration the active ingredient profile predicts. The £20 "natural" product, by contrast, is a plant-based formulation whose active-ingredient profile is not the performance lever the marketing label leans on. The marketing label leans on the word "natural." The Which? test is the cleanest evidence the 2026 UK market has produced that the marketing label and the performance lever are not the same thing.

The performance difference is not small. The £4 spray lasted longest in the Which? test. The £20 "natural" product offered essentially no protection at the two-hour mark. A consumer who bought the £20 product for the evening garden and the consumer who bought the £4 product for the same evening are not in the same protection state at the two-hour mark, and they paid a five-times price difference to be in the worse state.

The three-lab convergence

The reason this is a story and not a one-off test result is the three-lab convergence. The 60 Millions test, the Which? test, and the Consumer Reports roundup are independent. They do not share methodology, they do not share test product, and they do not share results. They land on the same point from three independent angles, in three regulatory environments, on three different product mixes. The shared point is the one the consumer needs to read.

The shared point is not "all natural repellents are bad." DEET and picaridin are synthetic active ingredients, and the consumer-lab data confirms they work at the listed concentration. The shared point is that the "natural" marketing label is not a regulated health claim, and the products that lean on it are not performing at the level the label implies. The consumer who reads the active-ingredient line on the back of the can is the consumer who gets the performance they paid for.

The protection layer that does not depend on the can

The protection layer that does not depend on the active-ingredient line on the can is the physical-barrier layer. A treated or untreated mosquito net, fitted correctly in a sleeping room, a window screen in good repair, a long-sleeved layer in the evening: these are the protection layers that do not require a re-application interval, do not require a price tier, and do not require a marketing label to be honest. They are also the protection layers whose cost is paid once, not at the re-application interval.

The recent DEET-conditioning literature is the structural reason the physical-barrier framing is now the more honest one. A 2026 European mosquito population under sustained DEET pressure is not the same mosquito population as the one a 1990s repellent label was tested against. The consumer-lab results this week, read together, are the cleanest evidence the 2026 market has produced that the active-ingredient-vs-label distinction is the one to make, and the physical-barrier-vs-supplement distinction is the one that travels further.

What to take to the shop

The three consumer-lab results this week, read together, support three practical moves. The first is to read the active-ingredient line on the can, not the marketing label. The second is to apply at the recommended interval, not at the first-bite interval. The third is to put a fitted barrier between you and the night-biting mosquito, because the barrier is the protection layer that does not depend on either of the first two. The £4 spray that lasted longest in the Which? test is the £4 spray whose active ingredient is on the back of the can. The £20 "natural" spray that did not is the £20 spray whose marketing label was on the front.

Sources

Published 2026-07-03 · Mosticare Editorial