Step Aside DEET, Study Finds Coconut Oil Works Better At Repelling Insects

There's been a lot of talk about a recent study that showed catnip lotion is just as effective as DEET at repelling mosquitoes. With researchers looking for economical and healthy alternatives to DEET, the future of insect repellents looks promising. Along the same lines, a study completed in 2018 could be the source for yet another alternative. As published in Scientific Reports, the USDA Agricultural Research Service team found that the fatty acids derived from coconut oil were also just as effective as DEET in repelling mosquitoes. And against biting flies, the results were even better. However, that doesn't mean you can slather off-the-shelf coconut oil on your skin and get the same effect, since coconut oil showed no repellency before undergoing a process called hydrolysis.

In a Lincoln, Nebraska study led by entomologist Junwei Zhu, the Agroecosystem Management Research Unit tested solutions made from coconut oil against bugs like biting flies, bed bugs, ticks, and mosquitoes, comparing them to DEET. In Zhu's own words, "Coconut oil itself is not a repellent." Hydrolysis, though, frees the fatty acids from the triglyceride chains in coconut oil. Those acids are mainly lauric, capric, and caprylic acids and the methyl esters that go with them, and they showed long lasting repellency in lab testing. The freed acids repelled ticks for about a week and biting flies and bed bugs for two weeks, while DEET faded after roughly three days.

Zhu's research objectives included studying repellents and biopesticides to find solutions for cattle pests like stable flies and horn flies. When Zhu and his team suspended the freed fatty acids in a starch based solution and applied it to cattle in field trials, it provided 96 hours of protection against biting flies. If you're considering alternatives to DEET bug repellent, you might be wondering why a study conducted in 2018, which showed such promising results, hasn't led to a product on the shelf today. But the truth is that the Agroecosystem Management Research Unit's research is ongoing. In 2023, an update showed that the fatty acids are being tested in lavender-based lotions and US military fabrics. 

Until there's an approved product for humans that uses fatty acids derived from coconut oil, sticking with what's on the EPA's list is the best choice. There are eight active ingredients on the list, including oil of citronella, catnip oil, and picaridin, and approved products will show the registration number on the label. A few other things you can do until a coconut-based repellent hits the shelves are to grow more mosquito repelling plants, keep standing water out of your yard, and create a 'bucket of doom' to kill larvae. These can go a long way toward making your outdoor living spaces less attractive to mosquitoes.