Lemongrass oil repels mosquitoes by interfering with their ability to detect the chemical signals your skin gives off, essentially jamming their sensors so they can’t find you. You can make an effective repellent at home using either a carrier oil infusion (the simplest method) or by diluting store-bought lemongrass essential oil into a spray or balm. The protection typically lasts 60 to 110 minutes per application, depending on how you prepare it.
How Lemongrass Oil Works Against Mosquitoes
The key compounds in lemongrass, primarily citral and geraniol, block mosquitoes from detecting the butyric acid and other attractant chemicals your body naturally releases. Rather than killing mosquitoes, these compounds overwhelm their chemical-sensing system so they fly past you without landing.
Lemongrass oil is particularly effective against common house mosquitoes (the type that bites at night). In controlled testing, lemongrass oil mixed with coconut oil provided about 112 minutes of protection against these mosquitoes and roughly 87 minutes against the species that carries dengue and Zika. That’s meaningful protection, though far less than DEET-based products, which can last 4 to 5 hours at higher concentrations.
The Carrier Oil Infusion Method
This is the most accessible approach if you have fresh or dried lemongrass on hand and want to extract the oil yourself. You don’t need any special equipment.
Start with about 130 grams (roughly 4.5 ounces) of lemongrass stalks, chopped into small pieces. Dried lemongrass produces a higher oil yield than fresh, so if you can dry it first, do so. Place the chopped lemongrass in a glass jar and cover it with 70 ml (about 5 tablespoons) of a light carrier oil. Olive oil and coconut oil both work well. Coconut oil actually improved protection times in research compared to olive oil, boosting lemongrass performance by nearly 30 minutes against some mosquito species.
Seal the jar and let it sit at room temperature for 18 to 24 hours. Then warm the jar in a water bath at about 78°C (170°F) for 30 minutes to help release remaining volatile compounds. Strain out the plant material through cheesecloth, squeezing firmly to extract as much infused oil as possible. What you’re left with is a lemongrass-infused oil that you can apply directly to your skin.
This method yields roughly a 2% oil concentration, which is a reasonable starting point for a repellent. You can repeat the infusion process with fresh lemongrass in the same oil to increase potency.
Making a Spray From Essential Oil
If you’d rather skip the extraction and use pre-made lemongrass essential oil (available at most health food stores), you can mix a repellent spray in minutes. This gives you more control over concentration and is the more practical option for most people.
For a body spray, mix 10 to 15 drops of lemongrass essential oil with one cup of water and add a splash of witch hazel or rubbing alcohol. Witch hazel acts as a natural emulsifier, helping the oil distribute evenly through the water instead of floating on top. Without it, you’ll get uneven coverage and the oil will clog your spray nozzle. Pour the mixture into a glass spray bottle (essential oils can degrade plastic over time) and shake well before each use.
For a rub-on balm, which stays on your skin longer than a spray, mix 5 to 10 drops of lemongrass essential oil per ounce of coconut oil. This creates a smooth, moisturizing layer that releases the repellent compounds gradually. The coconut oil base also helps slow evaporation, which is one of the main reasons natural repellents wear off so quickly.
Why the Carrier Oil Matters
Lemongrass essential oil should never be applied directly to skin without dilution. Citral, the primary active compound, is a known skin sensitizer. At concentrations around 4 to 5%, it caused allergic reactions in 20 to 49% of test subjects in dermal studies. Keeping your blend at 5 to 10 drops per ounce of carrier oil stays well within safe territory for most people, but it’s smart to test a small patch on your inner forearm and wait an hour before applying broadly.
Coconut oil is the best carrier choice for repellent purposes specifically. Research comparing lemongrass oil in coconut oil versus olive oil found that the coconut oil version provided noticeably longer protection, roughly 87 minutes versus 59 minutes against dengue-carrying mosquitoes. The reason likely comes down to how each oil interacts with skin and controls the release rate of the volatile compounds.
How Long Protection Lasts
Expect to reapply every 60 to 90 minutes for reliable coverage. This is the biggest tradeoff with any plant-based repellent compared to synthetic options. A product with 23.8% DEET provides about 5 hours of complete protection. A blend containing 1% lemongrass oil alongside citronella and other botanicals provided only about 19 minutes in one University of Florida comparison test, though that was a very low concentration.
At higher concentrations applied in a carrier oil, the numbers improve significantly. Pure lemongrass oil in coconut oil provided 112 minutes of protection against common house mosquitoes in lab conditions. Real-world performance will be shorter, since sweat, wind, and movement all speed up evaporation. Plan on reapplying roughly every hour if you’re outdoors and active.
Storing Your Repellent
The volatile compounds in lemongrass oil, especially citral, break down when exposed to light, heat, and oxygen. Store your repellent in a dark glass bottle, in a cool place, with the cap sealed tightly. A refrigerator is ideal. Under these conditions, a properly stored blend should remain potent for several weeks. If the lemongrass scent fades noticeably, the active compounds have degraded and you should make a fresh batch.
For outdoor use on your yard or patio, you can make a larger batch by mixing 20 to 30 drops of lemongrass essential oil per gallon of water with a small squirt of dish soap (which acts as the emulsifier at this scale). Spray this on grass, bushes, and around seating areas. It won’t last as long as a skin application since it’s more dilute and exposed to the elements, so reapply every few hours during outdoor gatherings.
Boosting Effectiveness
Lemongrass oil works best as part of a blend rather than on its own. Adding a few drops of citronella oil, which comes from a closely related plant, broadens the range of mosquito species repelled. Geranium oil is another good addition. Each targets slightly different receptors in the mosquito’s sensory system, so combining them creates a more complete barrier.
A practical combination for a spray bottle: 8 drops lemongrass oil, 5 drops citronella oil, and 3 drops geranium oil in one cup of water with a tablespoon of witch hazel. For a balm, use the same ratio of oils in two ounces of coconut oil. Adding a few drops of lavender oil softens the blend and reduces the chance of skin irritation without diminishing repellent performance.
No matter how you prepare it, the single most important thing for extending protection time is reapplication. Set a timer on your phone for 60 minutes when you head outside, and reapply as soon as the scent starts to fade on your skin.