Catnip Lotion Matches Deet in Mosquito Trials

A locally developed catnip lotion has shown to be “just as effective as Deet” in repelling mosquitoes, according to tests conducted in Uganda.

Catnip, scientifically known as Nepeta cataria, is a herb from the mint family. The substance in the plant that creates a euphoric effect in cats, called nepetalactone, is also known to deter insects, but until now, this property hasn’t been commercially utilized.

New solutions are crucial in the ongoing battle against malaria, which is transmitted by mosquitoes and affects about 282 million people yearly, causing around 610,000 deaths—predominantly among young children in African nations. There are significant worries about increasing resistance to both insecticides and the primary medications used to treat the disease.

In a study revealed at a Society for Experimental Biology conference in Florence, researchers from Uganda and Wales observed that mosquitoes looking for a blood meal were less inclined to land on individuals who had applied catnip-based lotions.

Dr. Simon Scofield, a senior lecturer at Cardiff University, noted, “We discovered that a lotion containing 6% catnip oil was just as effective as Deet, and a 2% concentration was only slightly less so.”

He added that Deet is often unaffordable for many rural Ugandan farmers, making commercially available repellents impractical. “Our aim was to create an effective repellent while ensuring local involvement in its production to keep costs low,” he explained.

Interestingly, the study did not focus on whether local cats were attracted to those wearing the lotion. “We didn’t check if cats were drawn to it, but since nepetalactone is known to attract them, I wouldn’t be surprised if they were,” Scofield admitted.

Initial laboratory testing affirmed that catnip oil could serve as an effective insect repellent. Following that, the lotion underwent successful field testing in eastern Uganda, where mosquito landings on volunteers were recorded over one evening.

Participants in the trial either used Deet, a lotion containing 2% or 6% catnip, or placebo creams. The research also indicated that the lotion could be made by a community enterprise. Currently, it’s being distributed for free with grant support, but plans exist to increase production and eventually sell it to create a sustainable income for local workers.

“Ultimately, if we can sell and distribute the repellent at a low cost, it should generate a self-sustaining system benefiting everyone involved,” Scofield said.

The Deet lotion used in this comparison contained 15% Deet, which is the most common formulation in Uganda. Travelers from the UK are advised to use repellents with at least 50% Deet when visiting malaria-prone areas.

Swai Kyeba, an entomologist from the Ifakara Health Institute in Tanzania who wasn’t part of the study, remarked, “New vector-control tools are essential in the fight against malaria, especially those that are affordable and locally produced to enhance accessibility.”

He did express some concerns, stating that compliance with topical repellents can be an issue because they require frequent reapplication, which limits their effectiveness as primary prevention tools. Kyeba recommended further research on how Ugandan households utilize existing repellents before scaling up catnip lotion production.