Citronella Oil Benefits, How to Use, Side Effects and Safety

For centuries, citronella has been used for a variety of purposes, including:

• as an insect repellent
• as an antifungal agent
• to treat parasitic infections
• to promote wound healing
• to lift mood or fight fatigue
• in perfumes or as a flavor additive in food

But does scientific research support these uses? While research into citronella and other essential oils continues, there's some evidence that citronella oil does have certain health benefits.

Let's take a deeper dive into what research has found so far.

Insect repellent

A 2011 review of 11 studies looked at the effectiveness of various citronella preparations in preventing mosquito bites. It concluded that using citronella oil together with vanillin (found in vanilla beans) provided mosquito protection for up to three hours.

The study also found that DEET provided protection for a much longer period of time than just citronella oil on its own.

A 2015 study compared the ability of DEET, citronella oil, and fennel oil to repel mosquitoes. Researchers found that DEET had a protection rating of over 90 percent over six hours.

Citronella and fennel oil had protection ratings of about 57 percent and 47 percent, respectively, after only two hours.

Another study assessed the effectiveness of several mosquito repellents, and concluded that citronella candles were of little use as a mosquito repellent.

Antifungal agent

Several studies have found that citronella oil has certain antifungal properties that may help weaken or destroy certain types of fungi that can cause health problems.

A 2013 study evaluated the antifungal activity of citronella oil against a strain of fungus known as Aspergillus niger. This common fungus is thought to cause lung and sinus infections in people with weakened immune systems.

The study found that citronella oil had the ability to destroy the cell wall of the fungus and kill the organisms within the cell that can cause infection. This led the researchers to suggest citronella oil may have the potential to be used as a safe and environmentally friendly fungicide.

An earlier study looked at the antibacterial and antifungal activity of ten essential oils and found that citronella oil was effective against all 12 fungi that were tested. The same study found that citronella oil managed to inhibit 15 of 22 bacteria, while eucalyptus, lemongrass, peppermint, and orange oils were effective against all 22 bacterial strains.

A publication from 2016 looked at the effectiveness of citronella and cinnamon oil in fighting Candida albicans, a fungus that can cause infections in the mouth and other parts of the body.

Both essential oils initially reduced the number of viable microorganisms. However, after 48 hours the effect wasn't significant. The authors suggest that a daily application of a solution of either oil may be effective in reducing this fungus.

Wound healing

Based on recent research, citronella oil may have the potential to speed up the healing of wounds. This may be of particular importance for people with diabetes, as wounds tend to heal more slowly with this condition.

In a 2016 animal study, researchers looked at the effect that citronella oil had on the healing of Candida-infected wounds in a diabetic mouse model. The citronella oil had both an antifungal and anti-inflammatory effect. The researchers suggested that the combination of these two factors led to accelerated wound healing.

Weight loss

A 2015 study in rats assessed the effects of inhaling citronella oil and some of its components on weight. Researchers found that inhaling the components of citronella oil decreased feeding, lowered cholesterol, and slowed weight gain.

Physiological effects of inhalation

A 2001 study investigated the effects of inhaling citronella, lavender, and rosemary essential oils. Lavender was found to have a relaxing effect and rosemary was found to have a stimulating effect on the brain. Citronella, on the other hand, had a more complex in-between effect. The writers suggest that the effects of citronella could vary by individual.

You can use citronella oil in a variety of ways. Here are some suggestions.

Spray

A spray application may be good for freshening up a room or applying to your skin as an insect repellent. To make a citronella oil spray:

1. Add citronella oil to water in a glass spray bottle. The National Association for Holistic Aromatherapy (NAHA) recommends 10 to 15 drops per ounce of water.
2. Optional step: Essential oils don't dissolve in water. Consider adding a dispersing agent such as solubol to your solution.
3. Shake the bottle well before spraying.

Because citronella oil has a shorter time span of effectiveness than repellents like DEET, you will need to reapply more often if you're using it as an insect repellent.

Diffuser

A diffuser can be used to disperse a scent through a room. Like the spray application, you may want to use this method to repel insects or add a pleasant fragrance to a room.

Diffusers typically come with a specific set of instructions. To use citronella oil safely in a diffuser, be sure to follow the product instructions carefully.

Massage oils and creams

Citronella oil can also be added to oils and creams for topical applications. Using citronella oil in this way may help kill germs and fungi on the skin and also promote wound healing.

Always dilute essential oils in a carrier oil before being applying to the skin.

Here's how to make a citronella massage oil or lotion.

To make a massage oil:

• Dilute citronella oil in a carrier oil, like jojoba oil or coconut oil.
• The NAHA recommends adding 15 drops of essential oil per ounce of carrier oil for a 2.5 percent dilution.
• For sensitive skin, you may want to use a one percent solution (6 drops per ounce of carrier oil).

To make a cream or lotion:

• Dilute citronella oil in an unscented cream or lotion.
• The NAHA recommends using a 1 to 2.5 percent dilution for normal skin (6 to 15 drops per ounce), and a 0.5 to 1 percent dilution for sensitive skin (3 to 6 drops per ounce).

Follow these tips for using citronella oil safely:

• Always dilute citronella oil properly before using. Never use undiluted citronella oil on your skin.
• Essential oils are very concentrated and can be toxic if consumed. Keep citronella oil out of reach of children and pets.
• Don't take citronella oil internally.
• When using citronella oil for aromatherapy, make sure the space you're in is well-ventilated. Consider children and pets who might be inhaling the aromatherapy. Some essential oils are dangerous.
• If you're pregnant, breastfeeding, or taking any prescription medications, talk to your doctor before using citronella oil.

Citronella oil can cause skin irritation or allergy. When this happens, the area may become red, blotchy, itchy, or swollen.

If you're concerned about a possible skin reaction, test some diluted citronella oil on a small area of your skin before using it for topical applications. If you have a reaction, avoid using citronella oil or products that contain it.

Although anaphylaxis, a severe allergic reaction, hasn't been documented in response to citronella oil, it's good to know the signs since it's a medical emergency. Look out for:

• difficulty breathing
• wheezing or coughing
• swollen throat
• red rash
• tightness in the chest
• nausea
• diarrhea

You can find citronella oil in natural food stores or online.

To find a good quality oil, keep these tips in mind:

• Look for a scientific name on the label — Cymbopogon nardus or Cymbopogon winterianus. You may also see C. nardus referred to as 'Ceylon type' and C. winterianus referred to as 'Java type.'
• Note that lemongrass (Cymbopogon citratus) is a different essential oil but has a similar scientific name. If you're looking for citronella, don't confuse the two.
• Make sure the oil is in a dark-colored bottle as light can damage essential oils.
• If possible, smell the oil before buying. Citronella has a distinct scent. If it doesn't smell like citronella, don't buy it.
• Be cautious of any claims that a product treats a specific condition. The FDA doesn't regulate essential oils in the same way as drugs.
• Check the label for a purity statement. If the product isn't 100 percent essential oil, the label should let you know.

Citronella oil is often used as an insect repellent, although research has indicated it may also have antifungal properties and help with wound healing.

You can use citronella oil in a diffuser or spray bottle, or you can dilute it in an oil or lotion before applying it to your skin.

If you have questions or concerns about citronella oil, talk to your doctor before using it.