We're coming off one of the hottest summers on record and muggy temps could persist through early fall in some parts of the country. What does that mean? Your days of swatting away flying (biting!) nuisances may not be over yet considering that bugs are more active in higher temperatures.

Spending more months outdoors co-existing with nature's critters means coating yourself in more bug spray — not great since DEET-based products can cause health problems if used in excess, per the Centers for Disease Control and Prevention.

Given that, it makes sense to try a safer natural option, such as an essential-oil bug repellent, which poses less risk to both you and Mother Earth.

How Do Essential Oils Repel Bugs?

First, a quick refresher: Essential oils are unique aromatic compounds extracted from plants. Beyond being the fragrant ingredient in your aromatherapy diffuser, they contain powerful and potent properties that have evolved to help plants prosper in their environments.

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"Each essential oil is made up of multiple chemical constituents (with names like geraniol, citronellol, citronellal, linalool)," explains Sarah Villafranco, MD, emergency physician and founder of organic skincare brand Osmia.

These compounds protect the plant and fight off certain insects and invaders, says Michelle K. Gagnon, founder of Bio Alchemy Olfactive and an advisor to THE WELL. "They can attract pollinators (like bees and butterflies), and they can also repel predatory insects, bacteria and fungus." Gagnon goes on to explain that "we’re accessing the same compounds that the plants use to keep themselves safe and healthy to deter certain species."

But how exactly do they work against insects such as mosquitoes? The essential oils contain chemical components that can block an insect’s odorant receptors, which they’d otherwise use to track down humans by finding scents such as sweat, according to research.

5 Essential Oils That Repel Mosquitoes

Thyme

In an animal study from 2022, thyme essential oil applied topically to mice provided a 91 percent protection rate against mosquitos. And while more research on humans is needed to truly determine the efficacy of this essential oil as a bug repellent, the findings are pretty impressive — and might offer a look into thyme’s ability to protect people from insects and any diseases they’re carrying, too. The secret to thyme’s repelling success? The compounds found in the essential oil extracted from the plant, such as thymol, p-cymene, carvacrol, linalool and alpha-terpinene, according to the aforementioned study.

That being said, there are hundreds of species of thyme and their chemical components vary. Gagnon recommends using the linalool variety (which you’ll likely see sold as "thyme ct. linalool"). That’s because it has anti-inflammatory properties and is "a little more gentle for topical application," she explains.

Lavender

Known for its ability to imbue any space with relaxing spa-like vibes, lavender is also great for keeping mosquitoes away. In fact, a 2002 study on mice found alpha-terpinene, a chemical compound in the purple plant, to be more effective at repelling the bugs than DEET when applied topically. And like thyme, lavender also contains insect-repelling linalool, notes Dr. Villafranco.

Cedarwood

Looking to ward off more than just mosquitoes? Gagnon praises cedarwood (specifically the Juniperus virginiana variety) as one of the most effective essential-oil bug repellents. This type of cedarwood is known for its strong odor, which is what helps repel a range of insects — clothes moths, flour beetles, cockroaches, ants and, of course, mosquitoes — according to a 2022 study.

Lemon Eucalyptus Oils

When it comes to using eucalyptus to keep away critters, you have two options: lemon eucalyptus oil or oil of lemon eucalyptus (OLE). Here is the difference: Though both are made from the leaves of the lemon eucalyptus tree and can credit their inclusion of PMD (p-menthane-3,8-diol) for their bug-repelling powers. The former is a natural product (an essential oil) that also contains chemical constituents, such as citronella, limonene and linalool, that also help fend off insects, according to research.

OLE, on the other hand, is "a refined and processed version of lemon eucalyptus essential oil, with a dramatically increased content of the compound PMD," says Dr. Villafranco. So, no, it’s not technically an essential-oil bug repellent. But it’s pretty darn powerful at keeping critters away —  so much so that the CDC has approved OLE as an effective ingredient in insect repellent. But if you want to stick to an unprocessed product, lemon eucalyptus oil (vs. OLE) would be your best bet.

Basil

The same green herb often found atop pizzas can help keep mosquitoes away — at least its essential oil can. That’s because, according to a 2009 study, it contains linalool, methyl cinnamate-linalool, geranial and geraniol. While all four constituents showed repelling properties, researchers found the geraniol to be the most effective at protecting against mosquitoes. "There really isn’t enough research in this area to say for certain what the mechanism is," says Dr. Villafranco. "But it’s possible that aromachemicals like geraniol and linalool interfere with the olfactory receptors of mosquitoes," inhibiting their ability to locate humans and, in turn, bite them.

How to Repel Bugs Natually

Mix Essential Oils

Because each of these essential oils contains mosquito-repelling compounds, they can work on their own. But their effects are even more powerful when used together, according to Gagnon.

And the research backs this up: A critical review of the chemical composition of essential oils found that "a synergistic effect is observed when the combination of substances is greater than the sum of the individual effects."

Dr. Villafranco explains why: "When you have one essential oil rich in certain constituents and another oil rich in different constituents, you may be able to achieve an additive effect."

Burn Incense

Another technique Gagnon uses to keep critters away? Burning natural incense. You can find some that contain lavender essential oils., such as the ones from Province Apothecary. "Whenever I’m outside, I’ll burn plant material — like frankincense, brue resin or opoponax resin — on a piece of charcoal. It creates an aromatic smoke, which naturally deters flying creatures from entering the space," she says. Research suggests this is because the volatile elements within the burning dried plant material can help deter mosquitoes.

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Use a Safe Spray

Gagnon's go-to way of using essential oils to fend off bugs is in a spray for mist application since it allows her to reapply quickly and easily throughout the day (and, unlike with a carrier oil, it doesn't feel balmy in humidity). "I combine the desired essential oils and dilute them with water," she shares, adding that you have to shake well before spraying since oil and water naturally separate.

It’s important to note, however, that essential oils are "volatile compounds," meaning they evaporate into the air fairly quickly, says Dr. Villafranco. As such, they "need to be reapplied often to remain effective." For optimal protection, consider reapplying your essential oil spray roughly every hour, especially if you're out in the heat and sweating.

Gagnon also suggests covering both your skin and clothes since "[essential oils] last a little bit longer on fabric than they do on skin."

If making a formula at home, it’s important to check the safety specifics of each essential oil, says Dr. Villafranco, who suggests asking questions such as “what’s the maximum skin concentration?” “can it cause sun sensitivity?” “is it unsafe for any specific populations (e.g. pregnant people, infants, pets)?” To find out those answers and more, check out the online resources from the Tisserand Institute, an organization devoted to science-backed education of essential oils and aromatherapy.

How to Make Your Own Essential-Oil Bug Spray

Bio Alchemy Olfactive's Gagnon shares her personal recipe:

Ingredients:

• 1-ounce bottle
• 1 mL (~25 drops) essential oil
• 7 mL alcohol (optional, but not rubbing alcohol)
• 22 mL distilled water

Directions:

• In the bottle, mix all fluids together and shake.