Lemongrass oil does repel mosquitoes, but its protection is short-lived compared to conventional repellents. In field studies, topical lemongrass essential oil provided 74–95% protection against mosquitoes, lasting about 2.5 hours before needing reapplication. That’s a meaningful effect, but it fades fast. DEET-based products protect for 2 to 12 hours, and picaridin lasts 5 to 14 hours, making them far more practical for extended outdoor time.
How Well Lemongrass Oil Actually Works
Lemongrass contains compounds closely related to citronella, which is one of the most widely recognized natural mosquito deterrents. These compounds interfere with the receptors mosquitoes use to locate human skin, making it harder for them to find you.
The numbers vary depending on how the oil is prepared. A 2015 study found that lemongrass essential oil combined with olive oil as a carrier provided 98.8% protection against the southern house mosquito. That’s an impressive figure, but it came under controlled conditions with a specific mosquito species. Field studies, where people are outdoors with multiple mosquito species active, showed a wider range of 74–95% protection that dropped off after roughly 2.5 hours. The takeaway: lemongrass oil works, but you’ll be reapplying frequently if you rely on it alone.
Lemongrass Plants Won’t Protect Your Patio
One of the most common misconceptions is that growing lemongrass near your patio or doorway will keep mosquitoes at bay. It won’t. The living plant does contain the same citronella-type compounds found in the essential oil, but the concentration released into the air by an intact plant is far too low to deter mosquitoes in any meaningful way. The oils need to be extracted and concentrated before they have a real repellent effect. Simply sitting near a lemongrass plant is no different from sitting near any other ornamental grass when it comes to mosquito protection.
Crushing the leaves and rubbing them on your skin releases more of the active compounds, but still far less than a properly formulated essential oil product. If you’re growing lemongrass, enjoy it for cooking. Don’t count on it for pest control.
How It Compares to DEET and Picaridin
The EPA does not register any mosquito repellent with lemongrass oil as an active ingredient. That doesn’t mean the oil is dangerous. It means it falls into a category of “minimum risk” plant-based products that haven’t been formally evaluated for effectiveness by federal regulators. In practical terms, this means no standardized testing confirms how long a given lemongrass product will protect you, and manufacturers aren’t required to prove specific claims about duration or efficacy.
DEET and picaridin, by contrast, are thoroughly tested and EPA-registered. A single application of a 20–30% DEET formula can last 5 hours or more. Picaridin at similar concentrations often lasts even longer. For situations where mosquito-borne illness is a real concern (tropical travel, areas with West Nile virus activity), these conventional options are significantly more reliable. Lemongrass oil is better suited to low-risk backyard situations where you’re willing to reapply every couple of hours.
Applying Lemongrass Oil Safely
Undiluted lemongrass essential oil should never go directly on your skin. It can cause irritation, redness, and sensitization, especially with repeated use. The standard approach is to dilute it in a carrier oil like coconut, jojoba, or olive oil. For a body application, a concentration of 1–3% is a reasonable starting point. That translates to roughly 6 to 18 drops of essential oil per ounce of carrier oil. Start at the lower end and increase only if you don’t notice irritation.
Some people mix lemongrass oil into spray bottles with water and a small amount of alcohol or witch hazel as an emulsifier. These sprays evaporate faster than oil-based applications, which means even shorter protection times. If you go this route, plan on reapplying every 30 to 60 minutes.
Risks for Pets and Children
Cats are especially vulnerable to essential oil exposure. They lack a specific liver enzyme needed to break down certain plant compounds, which means oils that are harmless to humans can build up to toxic levels in a cat’s system. Their grooming habits compound the risk: if lemongrass oil lands on their fur, they’ll ingest it. Dogs are less sensitive but still at risk for toxicity from concentrated oils. Never apply undiluted essential oils to any pet, and avoid using active diffusers (ultrasonic or nebulizing types) in rooms where animals spend time. These devices release microdroplets of oil into the air that settle on fur and are inhaled. Birds are particularly sensitive to aerosolized oils due to their respiratory anatomy.
Passive diffusers like reed sticks or candles are lower risk since they don’t emit oil droplets, but they can still cause respiratory irritation in animals with asthma, allergies, or chronic bronchitis. If you diffuse lemongrass oil at home, keep the area well ventilated and give pets access to oil-free rooms.
For young children, the same dilution caution applies. Keep essential oils stored out of reach, and avoid applying lemongrass oil to infants or toddlers without checking with a pediatrician first, since their skin absorbs compounds more readily than adult skin.