How to Use Essential Oils to Keep Mosquitoes and Black Flies Away

Mosquitoes are one of the most dangerous creatures on earth, killing 725,000 people every year through the transmission of deadly diseases. They incapacitate and injure millions more. Even if you don't live in a place where deadly diseases are likely, you're probably interested in avoiding a nasty, itchy bite. 

Essential oils can protect you from these bites. Here's everything you need to know about what essential oils keep mosquitoes away, and which essential oils mosquitoes don't like.

How Essential Oils Act as an Insect Repellent

Plants are used to fighting a battle against biting bugs and have evolved to protect themselves against insects that will do them harm. Although plants are trying to protect themselves from insects that want to eat them, many of the same compounds they use as defense can also repel mosquitoes and black flies for us.

Essential oils to repel mosquitoes contain one of five repelling compounds: nitrogen compounds (primarily alkaloids), terpenoids, phenolics, proteinase inhibitors, and growth regulators. The same keen sense of smell that lets mosquitoes detect your blood and move in for a bite also helps them detect these compounds in your essential oils (and avoid them).

A 2011 study found that many essential oils have repellent properties, while other studies have come out with somewhat more varied results. An Indian study found very high efficiency in repelling insects with neem oil, while a separate study found that essential oils worked to repel disease-carrying insects for 60-180 minutes in caged conditions.

While you'll have to apply them more frequently than synthetic options, essential oils to repel black flies, mosquitoes, and other biting insects are a safe method.

Why Synthetic Bug Sprays are Harmful

Essential oils are not the only option available for bug repellent. There are a host of other synthetic bug repellents that can keep mosquitoes from bothering you for hours. While these are certainly an option, they are not without their own unique drawbacks. Here are just a few of them:

The Environmental Cost

With global warming becoming a national conversation, many families are thinking carefully about what the impact of their personal choices means for the larger world. While DEET has been generally recognized as safe, it does have an environmental cost. It's not recommended to use it near waterways, because it can have a damaging effect on animals such as fish and birds.

Birth Defects

Women who are pregnant should also use caution when applying DEET. In rare cases, women who used large amounts of DEET during pregnancy gave birth to children who had birth defects, and in one case, the baby died.

May Not Be Safe for Children

There have been a few cases of children under the age of eight getting a rare but serious illness after applying DEET. These kids developed encephalopathy after application. Three of the children who developed this illness died. Although it is rare, it may not be a risk you are willing to take.

Not Always as Effective as Natural Solutions

DEET has a great track record for repelling insects, but it isn't the only synthetic bug repellent out there. Other repellents such as IR3535 aren't nearly as effective as DEET or most natural repellents.

Insects are Building Resistance 

The unfortunate problem with popular synthetic products is that mosquitoes and other biting insects are slowly developing resistance to them. The problem with DEET is that it may have neurological effects, and there's some evidence showing that mosquitoes may be able to genetically pass on their resistance to offspring. Over time, it's possible future generations may not find DEET useful as a repellent at all, or more likely, that it will be less effective.

While in most cases, any repellent approved by the EPA is better than no repellent when compared to mosquito-borne diseases, there's no reason to take risks. A natural repellent can still do a great job of warding off insects, without any of the side effects associated with synthetic sprays.

Essential Oils That Repel Insects

There are actually a number of highly effective essential oils that can be used to keep bugs away. While we have listed our favourites here, there are actually many different essential oils that repel insects.

Lemon Eucalyptus

By far the most effective essential oil repellent is lemon eucalyptus. A 2002 study conducted by the London School of Hygiene and Tropical Medicine found that Lemon Eucalyptus might actually be more effective at repelling insects than DEET itself, while having none of the side effects.

Lemon Eucalyptus essential oil works to repel insects because it contains para-menthane-3,8-diol (PMD), a compound that makes it harder for insects to detect the smell of your skin. 

This essential oil is powerful and effective, but the CDC recommends avoiding its use in children under the age of 3 due to the risk of skin allergy.

Lemongrass Oil

A 2005 study found that lemongrass in combination with olive oil provided 98% protection against the southern house mosquito. A more recent study also found that it repels stable flies and other biting insects as well. Lemongrass has small amounts of citronella as well as robust amounts of geraniol and neral, which work to repel insects.

Peppermint Oil

Most of us are familiar with the bright and invigorating scent of peppermint essential oil. These oils are used for a variety of other uses, from promoting alertness to soothing tired muscles. A study conducted by the University of Delhi also found it to be a powerful insect repellent.

In the study, blood starved mosquitoes were tested with human live bait in order to measure the effectiveness of peppermint essential oil against dengue-carrying species of mosquitoes. The study not only found that peppermint oil was a powerful repellent, but that it also helped to kill larvae. 


There has been a lot of conflicting information about citronella in terms of whether or not they truly prevent mosquito bites. This is due to some conflicting evidence in studies, with some showing it to be very effective, and some less so.

Fortunately, a meta-analysis was conducted on 11 high-quality citronella studies. It found that while citronella isn't quite as effective as DEET on its own, its close, and when paired with, vanillin, it works almost as well.

Citronella is a very popular essential oil for repelling mosquitoes and is included in a variety of different repellent devices such as candles, tiki torch oil, and sprays. All of these repellents work best when vanillin included, so see if it is mixed in before purchasing for the best results.

How to Get the Best Results from Essential Oil Bug Sprays

Whether you make your own custom blend from essential oils you like the scent of or buy a premade spray that uses essential oils, there are ways you can improve the efficiency of the spray. Essential oils can vary in quality. 

Essential oils are made all over the world, and a great many factors can impact your use of the essential oil. Pesticide use on the plants the oils are derived from, how the essential oil is stored, and even diluted or adulterated products can all wind up on the same shelf.

If you're inexperienced with essential oils, you may not be able to tell quality on your own. If the product is diluted, it will not repel mosquitoes effectively. If the plants used to create the essential oils are filled with pesticides, you may not be getting the benefits you were seeking from natural repellents.

Luckily, you can figure out whether an essential oil is of fairly good quality by taking a careful look at the brand. Is the pricing really cheap compared to the same essential oil from other brands? The saying, “You get what you pay for,” follows essential oils too.

Is there information on the brand website or packaging about where the essential oils come from? Not all top quality essential oils are registered as organic, but information on the quality of the plants being used is an important clue. Good examples of plants that are still of ideal quality, but can't be registered, are plants procured through wildcrafting.

Before using an essential oil for the first time, smell it first. Does it smell the way you would expect? If it doesn't smell right, it might not be the pure essential oil you thought you were purchasing.

Repelling Insects with Bug Spray Made from Essential Oils

Essential oils are a powerful way to repel insects while protecting yourself from unwanted toxins. With essential oils, you can mix and match mosquito-repelling essential oils to create a scent that's pleasing to you and will do the job of repelling insects, all while staying safe and toxin-free. If you're worried about itchy bites from mosquitoes or black flies this summer, then essential oils may be the right choice for you.

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