Key takeaways
- Several plant-based oils provide varying levels of protection against mosquitoes and other insects, with effectiveness ranging from 30 minutes to 3 hours, depending on the specific oil and insect species.
- Some examples of repellents that may work include cedarwood, citronella, garlic, peppermint, and cinnamon essential oil.
- Not all natural insect repellents are safe for everyone, and they may require more frequent reapplication than N, N-diethyl-meta-toluamide (DEET).
Insect repellents help keep irritating or disease-carrying insects away. They are an important resource, as the viruses and parasites that certain insects can carry are a global public health concern.
All pesticides that are legally available in the United States have approval from the Environmental Protection Agency (EPA). However, pesticides can still contain harmful chemicals.
The EPA has issued a list of minimum-risk pesticide ingredients. Most of these are naturally occurring.
This article explores 10 natural insect repellents included in the EPA list of minimum-risk pesticide ingredients in more detail. It also discusses the potential risks of using them, the safety of DEET, and when to contact a doctor.
Cedarwood is a traditional insect repellent that people use around the home, adding this wood to wardrobes, drawers, and closets to repel moths.
A 2018 report from the U.S. Department of Agriculture (USDA) also states that Eastern Red cedarwood oil repels several types of ants and wood termites, and prevents wood decay.
However, cedarwood oil can also repel insects that affect humans. It is toxic to house flies and several mosquito species.
Additionally, a 2022 laboratory study showed that cedarwood oil repels several tick species, though its effectiveness may vary depending on tick size and oil concentration.
Cinnamon is a common spice, but people also use it to repel insects.
A 2021 study suggests that cinnamon, particularly in oil form, works as an insect repellent. In higher doses, it can also destroy some insects and prevent them from laying eggs.
Citronella and citronella oil typically come from the Cymbopogon nardus plant.
According to 2018 research, citronella likely provides protection for 30 minutes to 2 hours, but its effectiveness against all mosquito types is low.
Cloves and clove oil are present in various foods and medical products. People may also use them as an insect repellent.
A 2019 review and meta-analysis suggested that cloves may be a moderate repellent against mosquitoes in the Anopheles genus.
Some research suggests that clove oil may repel mosquitoes for up to 2 to 3 hours after application. However, researchers indicate that further studies into the efficacy of clove oil are necessary.
Most people know garlic as a flavorful ingredient, but its essential oil can also repel insects.
The scent of garlic may reduce mosquito attraction to human odor. Findings show that garlic oil is a strong mosquito repellent for the first 30 minutes after application, but its effect weakens thereafter. Some people take garlic tablets to keep mosquitoes away, but little evidence supports their effectiveness.
Peppermint comes from crossbreeding spearmint with water mint. Research suggests it is an effective insect repellent, with one 2022 study finding that peppermint oil may provide complete protection against the Anopheles dirus mosquito species for
Another 2020 study suggested that peppermint oil acts as a strong Aedes aegypti mosquito repellent for 30 minutes, after which it continues to repel them, but not as significantly.
Rosemary is an evergreen shrub that many people use as a culinary herb. Research suggests that rosemary essential oil may repel mosquitoes effectively.
Sesame oil comes from sesame seeds. It is often a natural ingredient in commercial insect repellents.
However, findings from 2020 suggest that sesame oil does not provide significant protection against Aedes aegypti mosquito bites or repel these insects.
Older 2015 research suggests that the oil may repel cockroaches at certain concentrations, but it was less effective than clove oil.
Spearmint, including spearmint oil, contains chemicals similar to those in peppermint. Research suggests that spearmint oil can be an effective Aedes aegypti mosquito repellent for the first 30 minutes after application, after which the effect begins to fade.
Thyme is a Mediterranean plant. 2019 research suggests that it
Research from 2020 suggested that other studies have also found thyme oil effective against insects. However, the researchers did not consider thyme oil an effective Aedes aegypti mosquito repellent when applied to a cotton ball.
Natural insect repellent products typically include instructions on the label that explain how to use them.
However, if a person is using the basic ingredients at home, it is important to look up how to use them safely. “Natural” does not always mean safe or nontoxic.
Personal use
Many of the above insect repellents are essential oils. When using these on the body, it is important to:
- dilute them at a safe ratio with a carrier oil, such as sweet almond oil
- patch test them first before using them on a larger area of skin
- avoid using them on pets, children, people with chronic conditions, or those who are pregnant
Never use undiluted essential oils on the skin or in water, including homemade cosmetic products or sprays.
Remember that natural insect repellents often become less effective over time. A person may need to keep using them to maintain their protection.
Around the home
There are several ways people can use natural insect repellents around the home. For example, people can:
- burn citronella candles when sitting outside
- use cedarwood balls or inserts inside closets or wardrobes
- use essential oils in areas where insects enter the home, such as door frames or windows
- add a few drops of essential oil to a diffuser
Again, it is crucial to check that these ingredients are safe to use around others first.
Never leave burning candles unattended, and ensure rooms are well-ventilated when using essential oils.
Natural insect repellents are not guaranteed to prevent bites from all insects. Some may repel certain bugs more effectively than others, or for varying amounts of time.
Most are not as well-researched as laboratory-made options, such as DEET, and they are also unregulated. This means the Food and Drug Administration (FDA) does not require proof that they are safe or pure before companies sell them.
Essential oils can cause side effects and are not safe for everyone. Adverse reactions can include:
- skin sensitivity
- allergic reactions
- respiratory irritation
- worsened symptoms for people with lung conditions
Additionally,
People should not ingest essential oils.
DEET is a common ingredient in insect and parasite repellents. It reduces how well bugs, such as mosquitoes and ticks, can smell people.
DEET can repel ticks for 2 to 10 hours and mosquitoes for 2 to 12 hours, depending on the concentration.
It is slightly toxic to humans, and there is a risk of neurotoxicity if people apply DEET underneath sunscreen. Neurotoxicity refers to damage or disruption to the nerves.
For this reason, DEET may be more suitable for some people than others, and people should avoid spraying it directly onto the face. However, the EPA suggests that DEET is not toxic when used correctly.
Speak with a doctor to determine whether natural insect repellents are suitable and how to use them safely.
If a person experiences a severe reaction to either insect bites or insect repellents, they should seek emergency help.
Anaphylaxis: Symptoms and what to do
Anaphylaxis is a severe allergic reaction that can be life threatening. The symptoms develop suddenly and include:
- hives
- swelling of the face or mouth
- wheezing
- fast, shallow breathing
- a fast heart rate
- clammy skin
- anxiety or confusion
- dizziness
- vomiting
- blue or white lips
- fainting or loss of consciousness
If someone has these symptoms:
- Check whether they are carrying an epinephrine pen. If they are, follow the instructions on the side of the pen to use it.
- Dial 911 or the number of the nearest emergency department.
- Assist the person in moving from a sitting position to lying down. If they have vomited, turn them onto their side.
- Stay with them until the emergency services arrive.
Some people may need more than one epinephrine injection. If the symptoms do not improve in 5 to 15 minutes, or they come back, use a second pen if the person has one.
Insect repellents help prevent insect bites and the transmission of insect-borne diseases. Many insect-repelling products are available, and many contain naturally occurring ingredients.
Natural insect repellents may work well for some people, but it is important to use them safely. Just because something is natural does not mean it is completely nontoxic. For example, some essential oils are toxic if ingested.
A person should seek medical attention as soon as possible if they experience a severe allergic reaction to an insect bite or a form of repellent.