Plants have evolved to emit fragrant compounds that offer some level of protection from insect attacks. These are preserved during the distillation process, so any high-quality essential oil will also contain them.
“Essential oils all comprise multiple chemical constituents with names like geraniol, citronellol, citronellal, and linalool. Studies are sparse on individual components, but some (like geraniol and vetiverol) are more active against insects than others,” Villafranco explains.
Some commonly available essential oils that are often used to keep bugs at bay include lemongrass, citronella, and geranium, says Villafranco. Mint, basil, and turmeric are also skin-safe oils that have been researched for their repellent properties.
“They all work reasonably well, but because they are volatile, meaning they evaporate into the air fairly quickly, they need to be reapplied frequently to remain effective. For that reason, I like vetiver, which stays on the skin much longer than most other essential oils,” Villafranco notes.