A cheap lotion made from a common garden herb – the same plant that sends cats into blissful rolling – has matched the industry-standard repellent DEET at keeping mosquitoes away, in field trials carried out in eastern Uganda. The finding raises the prospect of an affordable, locally grown defence against malaria in the places that need it most.
The herb is catnip, or Nepeta cataria, a member of the mint family. Its active compound, nepetalactone, is famous for the euphoria it triggers in cats, but it also repels insects – a property that had never been turned into a practical product. A team working between Uganda and Cardiff University set out to test whether it could. They presented their results at the Society for Experimental Biology conference in Florence, with the underlying study published in the journal Scientific Reports.
Using the human landing catch method, researchers measured how often mosquitoes settled on the legs of volunteers wearing different creams during evening exposure. A lotion containing 6 percent catnip oil performed as well as DEET, according to Dr Simon Scofield of Cardiff University, while a 2 percent version was only marginally less effective. Placebo creams, by contrast, offered little protection.
Why it matters
The stakes are hard to overstate. Malaria still infects roughly 282 million people a year and killed about 610,000 in 2024, most of them young children in African countries. Existing tools are under strain: mosquitoes are developing resistance to insecticides, and the parasites to the frontline drugs. DEET works, but it is often priced beyond the reach of the rural communities most exposed to the disease.
A repellent grown and produced locally could change that calculus. Catnip is inexpensive and easy to cultivate, so a homegrown lotion would not only lower the cost of protection but could create income for the farmers who grow it. The researchers caution that more work is needed before the lotion reaches households at scale. But the trial points to a rare kind of solution – one that is low-tech, low-cost and rooted in the communities it aims to protect.