Catnip lotion as effective as Deet at repelling mosquitoes, study finds
Researchers testing a cheap, homegrown oil in Uganda found what cats knew all along – it worked as well as the artificial chemical used globally
A homegrown catnip lotion has proven “just as effective as Deet” as a mosquito repellant in trials carried out in Uganda.
Catnip, or Nepeta cataria, is a common herb from the mint family. The chemical in the plant that causes feline euphoria – nepetalactone – also has insect-repelling properties but this has not previously been commercialised.
New tools are vital in the fight against malaria, the disease spread by mosquitoes that infects about 282 million people a year and killed 610,000 in 2024 – the majority of them young children in African countries. There are concerns about rising resistance to insecticides, as well as the frontline drugs used to treat the disease.
In a study presented at the Society for Experimental Biology conference in Florence on Tuesday, a team working between Uganda and Wales found mosquitoes seeking a blood meal were less likely to land on people wearing lotions made from catnip.
Dr Simon Scofield, a senior lecturer at Cardiff University, said: “We found that a 6% catnip oil was just as effective as Deet, and the 2% catnip oil was only marginally less effective than that.
“Deet is out of the price bracket for most rural Ugandan subsistence farmers, so buying commercially available mosquito repellents is just not practicable.
“We wanted to make a repellent, which is highly efficacious, but also allows local people to be involved in the production cycle so that it costs a minimal amount of money,” he said.
Whether or not local cats were more likely to follow lotion wearers was not part of the research, Scofield admitted. “We did not conduct any experiments to see if it is attractive to cats, but given that the active ingredient [nepetalactone] has well-known cat-attractive properties, I would expect they would quite like it,” he said.
In the first part of the evaluation, laboratory tests confirmed that catnip oil could be an effective insect repellent. Researchers then successfully tested the catnip repellent in the field in eastern Uganda by checking how many mosquitoes landed on volunteers’ legs over an evening.
Some volunteers used Deet (the world’s most widely used and effective insect repellent), some used a lotion with 2% concentration of catnip, others a 6% catnip lotion, while others used placebo creams.
The research also established that the lotion could be made locally by a community enterprise. So far it has been distributed for free, using grant funding, but the next phase of the project will see production increased and the lotion sold to create a sustainable income for workers.
“Once we know that we can sell and distribute the repellent at a low cost, that should generate a self-sustaining system where the money is flowing back to everybody at each stage in the development,” said Scofield.
The Deet (N,N-Diethyl-meta-toluamide) lotion used for comparison in the trial contains 15% Deet and is the most widely available in Uganda. Travellers from the UK visiting malaria-endemic regions are advised to use stronger repellents of at least 50% Deet.
Swai Kyeba, a research entomologist from the Ifakara Health Institute in Tanzania who was not involved in the study, said: “New vector-control tools are necessary in the fight against malaria, especially those that are cheap and locally produced, to help improve accessibility.
“However, a challenge with topical repellents is low compliance because they require regular application. This is why they remain a complementary tool in the fight against malaria.”
He urged further research on Ugandan households using currently available repellents before the catnip lotion production was scaled up.