A topical
insect repellent with extended duration of protection was obtained from mixtures of molecules based on two or more volatile repellent organic molecular species occurring naturally on the
human skin surface. The novel repellent comprises mixtures of lower, intermediate, and higher volatility
organic molecules. Active ingredients for formulations are obtained from homologous series of carboxylic acids, alcohols, ketones, and lactones which span a similar range of volatility and which occur naturally on the
skin surface. Volatile
silicone fluid imparts mildness and water repellency to the repellent formulations. The new natural repellent exhibits the
longevity and repellency that is comparable to N,N-diethyl-m-toluamide (
DEET), a synthetic compound employed in almost all commercial formulations, but the inventive natural repellent is more acceptable than
DEET, which has an unpleasant
odor and imparts a greasy feel to the
skin. The inventive
insect repellent, formulated in a volatile
silicone fluid, was shown to repel and incapacitate stable flies. This finding demonstrated that repellency was not limited to mosquitoes, but extends to other
biting flies or insects, thus demonstrating the utility of the novel
insect repellent for protecting pets and
livestock as well as humans.