Insect Repellent Ingredient May Protect against Coronavirus, UK Study Finds

An active compound found in insect repellents may provide protection from a strain of coronavirus that causes COVID-19, according to a preliminary study conducted by UK’s defence laboratory. Scientists at Defence Science and Technology Laboratory (DSTL) said in a statement that Citriodiol, the active ingredient in repellents such as Mosi-guard, had anti-viral properties if mixed with the virus in the liquid phase and on a test surface.

“Mixing a virus suspension with Mosi-guard spray or selected constituent components resulted in a reduction in SARS-CoV-2,” according to the yet-to-be published findings. However, it is unclear whether the spray would make any practical difference beyond frequent hand-washing and the use of alcohol-based hand sanitisers in protecting against the virus.

Citriodiol is derived from the leaves and twigs of Eucalyptus citriodora tree, and is marketed as a natural alternative to Deet, another ingredient used in insect repellents. The military scientists adopted two experimental approaches. The first approach asessed the anti-viral activity of the product when applied directly to the virus as a liquid drop.

In the second method, assessment of the product was done following its application to latex ‘synthetic skin’. The study found that one minute liquid suspension tests indicated that Mosi-guard has anti-viral activity against SARS-CoV-2 England-2 isolate if mixed with the virus in the liquid phase.

“Additionally, viral studies on latex indicated that Mosi-guard had antiviral activity against SARS-CoV-2 England-2 isolate,” the scientists said in a statement. The scientists said they are sharing their preliminary findings, which have not been peer-reviewed, in the hope that further research will be carried out.

“This research paper demonstrates preliminary findings on the effectiveness of Citriodiol against COVID-19,” the statement said. “DSTL is hopeful that the findings in this research can be used as a springboard for other organisations to expand and develop the research, as well as to confirm the findings in this publication,” it said.