Lemongrass essential oil repels mosquitoes for roughly 30 to 60 minutes per application, making it a viable natural option for short outdoor stints like backyard dinners or garden work. It won’t match the six-hour protection of DEET-based products, but it’s simple to make at home, recognized by the EPA as a minimum-risk pesticide ingredient, and pleasant to wear. Here’s how to make it and get the most out of it.
Why Lemongrass Works Against Mosquitoes
Lemongrass oil is roughly 70% citral, a compound that interferes with insects’ nervous systems by disrupting key neurotransmitters. In practical terms, the scent overwhelms the receptors mosquitoes use to find you, masking the carbon dioxide and body odors that normally attract them. A 10% lemongrass lotion reduced mosquito attraction for about 60 minutes in controlled lab testing, putting it in the upper tier of essential oils alongside peppermint and well above most other plant-based options.
That said, essential oil repellents evaporate faster than synthetic ones. DEET at the same 10% concentration lasted over six hours in the same study. The tradeoff is that lemongrass smells considerably better and avoids the sticky, plasticky feel many people dislike about conventional repellents.
Basic Spray Recipe
This water-based spray is the simplest version. You need:
- 10 drops lemongrass essential oil
- 2 tablespoons witch hazel or vodka (acts as a preservative and helps the oil mix with water)
- 2 tablespoons distilled water
- A small glass spray bottle (2 to 4 ounces works well)
Combine the witch hazel or vodka with the essential oil first and shake well. Then add the distilled water and shake again. The alcohol in witch hazel or vodka helps disperse the oil so it doesn’t just float on top, but you’ll still want to shake the bottle before every use since the oil and water will separate over time.
Oil-Based Version for Longer Protection
Oil evaporates more slowly than water, so an oil-based repellent stays on your skin longer and extends the effective window by slowing how fast the lemongrass compounds dissipate. Use a lightweight carrier oil like fractionated coconut oil, sweet almond oil, or jojoba oil.
Mix 10 to 12 drops of lemongrass essential oil per ounce (2 tablespoons) of carrier oil. This keeps the concentration around 2 to 3%, which is gentle enough for most adults’ skin while still delivering a strong scent barrier. Pour the blend into a small roll-on bottle or a glass dropper bottle and apply it directly to exposed skin, focusing on ankles, wrists, and the back of the neck where mosquitoes tend to target.
Boosting Protection With Oil Blends
Combining several repellent oils can broaden the scent profile and may improve effectiveness since different compounds target mosquito receptors in slightly different ways. A well-tested combination:
- 10 drops citronella oil
- 10 drops eucalyptus oil
- 10 drops lavender oil
- 2 tablespoons witch hazel or vodka
- 2 tablespoons distilled water
You can swap in lemongrass for the citronella (they’re close relatives in the same grass family) or add 10 drops of lemongrass on top of the blend. Cinnamon oil is another strong performer, reducing mosquito attraction for up to 120 minutes in testing, though it can be more irritating to skin. If you include it, use only 3 to 5 drops in a blend and do a patch test on your inner forearm first.
Getting the Oil to Mix Properly
Essential oils don’t dissolve in water on their own. If you skip the dispersing step, the oil sits in a layer on top, and your spray delivers an uneven dose: sometimes too much oil hitting your skin, sometimes almost none. Witch hazel and vodka help, but they’re imperfect emulsifiers.
For a more stable spray, you can use a dedicated solubilizer designed for essential oils. These are sold at soap-making supply shops and online. The typical ratio is 4 parts solubilizer to 1 part essential oil. Mix those together first until the liquid is clear, then stir into your water. The result is a spray that stays evenly mixed for weeks without separating.
If you don’t want to buy a solubilizer, high-proof vodka (at least 80 proof) works better than witch hazel for keeping things dispersed. You can also increase the alcohol-to-water ratio, using 3 tablespoons of vodka and 1 tablespoon of water instead of equal parts.
How to Apply for Best Results
Reapply every 30 to 60 minutes. This is the biggest practical difference between a homemade lemongrass spray and a store-bought DEET product. Set a timer on your phone if you’re outside for a while. Apply generously to all exposed skin, not just a light mist. The repellent effect depends on maintaining a scent cloud close to your skin’s surface, and a thin application fades faster.
Sweating and wind both speed up evaporation. If you’re exercising outdoors or it’s a breezy evening, lean toward the 30-minute reapplication window. The oil-based version holds up better in these conditions than the water-based spray.
Safety for Children and Pets
Children’s Hospital of Philadelphia recommends limiting essential oil use to children over age 3. Younger children have thinner, more permeable skin, and their developing respiratory systems are more vulnerable to aerosolized oils. For kids over 3, cut the essential oil concentration in half (5 drops instead of 10 in the basic recipe) and avoid spraying near their face. Apply it to clothing and exposed limbs instead.
Cats are particularly sensitive to essential oils because they lack certain liver enzymes needed to metabolize compounds like citral. Avoid spraying lemongrass repellent in enclosed spaces where cats spend time, and don’t apply it to a cat’s fur. Dogs tolerate lemongrass better, but concentrated oil can still irritate their skin and nose. If you’re using the spray in a shared outdoor space, keep the concentration moderate and let it dry on your skin before handling pets.
Storage and Shelf Life
Lemongrass essential oil has a shelf life of 2 to 3 years when stored properly, but a finished water-based spray degrades faster. Oxygen exposure is the main enemy: every time you open the bottle, air gets in and begins breaking down the active compounds. Heat and UV light accelerate the process.
Store your repellent in a dark or amber glass bottle, in a cool spot like a medicine cabinet or refrigerator. Avoid clear plastic bottles since the oil can degrade certain plastics over time, and glass blocks UV light better. A water-based spray is best used within 1 to 2 months. An oil-based blend lasts longer, closer to 3 to 6 months, because the carrier oil creates a more stable environment for the essential oil compounds.
If your repellent starts smelling stale, sharp, or “off” compared to when you first made it, the citral has likely oxidized. Toss it and make a fresh batch. Oxidized essential oils are more likely to cause skin irritation.