What to Buy Healthy Home & Appliances What Is Nootkatone Insect Repellent? Found in grapefruit skin, nootkatone might help keep mosquitos, ticks, and other biting bugs at bay. By Claire Gillespie Claire Gillespie Claire Gillespie is an experienced health and wellness writer. Her work appears across several publications including SELF, Women’s Health, Health, Vice, Verywell Mind, Headspace, and The Washington Post. health's editorial guidelines Updated on March 31, 2023 Medically reviewed by Steffini Stalos, DO Medically reviewed by Steffini Stalos, DO Steffini Stalos, DO, FCAP, is a pathology and lab medicine physician. She is also the chief medical officer of the lab consultancy firm Blood Associates, LLC. learn more Share this page on Facebook Share this page on Twitter Share this page on Pinterest Email this page The summer months may be full of sunshine and outdoor activities. However, that time also comes with the risk of insects. For the most part, insect bites are harmless and only cause mildly bothersome symptoms, like itching. However, some insects, like mosquitos, ticks, and fleas, carry diseases. Insect repellent is one of the best ways to avoid attracting insects. Still, some insects may become resistant to commonly used ingredients in repellent. In 2020, the Environmental Protection Agency (EPA) approved nootkatone, a natural ingredient found in grapefruit skin and Alaska yellow cedar trees, for insect repellents. As of 2023, nootkatone is not yet commercially available. Still, in the future, the ingredient may help keep insects at bay and reduce the spread of disease. Insect Stings: Symptoms, Treatments, and Prevention What Is Nootkatone? Nootkatone, found in small quantities in grapefruit skin and Alaska yellow cedar trees, can keep biting bugs away for several hours. In 2020, the EPA approved nootkatone for insecticides and repellents. The Centers for Disease Control and Prevention (CDC) discovered and developed nootkatone, which repels and kills ticks, mosquitos, and other biting bugs. "According to the CDC, nootkatone kills pests in a unique and different way, which is very important for mosquito control operations," David Brown, a technical advisor to the American Mosquito Control Association, told Health. As a food additive, the Food and Drug Administration has classified nootkatone as "generally considered safe." Also, the EPA confirmed to The New York Times that nootkatone is nontoxic to humans and other mammals, birds, fishes, and bees. How Does Nootkatone Work? Normally, mosquito control agencies use two pesticides to reduce adult mosquito populations: pyrethroids and organophosphates. "These products disrupt the nervous system of the target insect, resulting in mortality," explained Brown. In contrast, nootkatone works differently than pyrethroids and organophosphates. Therefore, nootkatone may work better than products containing other active ingredients that insects may have become resistant to. Still, it's unclear how nootkatone repels insects. Some experts believe that biting bugs do not like the smell or taste of the chemical. Nootkatone is responsible for the distinctive aroma and taste of grapefruit. "In some insects tested, areas treated with nootkatone were avoided prior to contact," Karla M. Addesso, PhD, an associate professor in the department of agricultural and environmental sciences at Tennessee State University, told Health. "This suggests that they can smell the nootkatone and that they don't like the smell. Other insects may need to contact the compound in order to detect it, and they may be repelled by the taste." How To Use Nootkatone Safely The CDC has partnered with Evolva to develop insect repellents using nootkatone. As of 2023, the EPA is reviewing Evolva's formula to ensure its safety and efficacy. However, when nootkatone becomes commercially available, people can use the formula on their skin and other items, like clothing, to protect against insects. Like previous insect repellents, you can spray nootkatone directly onto exposed areas. Also, manufacturers may use nootkatone in soaps, sprays, and lotions. Alternatives to Nootkatone The Food and Drug Administration has approved nootkatone as an active ingredient in insect repellent. However, the EPA must test and register any manufactured products containing the ingredient separately. Still, some natural compounds may work the same way nootkatone does when it comes to repelling bugs. For example, Nootka oil and grapefruit oil, available commercially, help repel bugs, noted Addesso. "The Nootka oil has a cedar-type smell, and the grapefruit oil is more citrusy due to the other compounds found in the oil," said Addesso. However, placing any pure essential oil directly on the skin is not advisable, as it may cause irritation. Instead, "you can place drops of oil on clothing directly if you are not worried about staining them, such as a hat or gloves you use for gardening," explained Addesso. "You can also dilute the oils in a carrier like coconut oil to make lotions as you would any other essential oil. If you make candles with the oils, you can use them outdoors in place of citronella candles." For other options, you can refer to the EPA's list of ingredients registered as skin-applied insect repellents, including catnip oil and citronella oil. "Environmental Protection Agency-registered products have undergone studies to ensure they are safe for use, and they are effective when the label directions are followed," said Brown. How To Prevent Insect Bites The fight against insect-borne diseases remains a priority for health officials. According to a report published in 2018 by the CDC, diseases caused by the bites of ticks, mosquitoes, and fleas have tripled in the United States since the mid-2000s. Those diseases include Lyme disease, anaplasmosis, and Rocky Mountain spotted fever from ticks. Also, mosquito-caused illnesses include West Nile, dengue, Zika, and chikungunya. Additionally, fleas can carry and transmit plague. Beyond using insect repellents, you can take precautions against mosquito bites, such as: Wearing long-sleeved shirts and long pantsUsing permethrin on any exposed items, such as clothing or backpacksUsing air conditioning or closing windows and doors to keep mosquitos out of your homeSleeping underneath a mosquito net if you are traveling to an area with disease-carrying mosquitos Also, to prevent tick bites, take note of the following tips: Keep away from tick-infested areas, like grassy, brushy, or wooded areas.Use permethrin on any exposed items.Check yourself, your pets, your children, and any exposed items for ticks.Shower after being outdoors. 15 Facts You Must Know About Ticks and Tick-Borne Illness A Quick Review Nootkatone is a natural ingredient in grapefruit skin and Alaska yellow cedar trees that can help repel insects. As of 2023, nootkatone is not yet commercially available. However, in the future, the ingredient may help decrease the spread of diseases carried by insects, like Lyme disease and malaria. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit 12 Sources Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. MedlinePlus. Insect bites and stings. Deletre E, Martin T, Duménil C, Chandre F. Insecticide resistance modifies mosquito response to DEET and natural repellents. Parasit Vectors. 2019;12(1):89. doi:10.1186/s13071-019-3343-9 Environmental Protection Agency. Nootkatone now registered by EPA. Clarkson TC, Janich AJ, Sanchez-Vargas I, et al. Nootkatone is an effective repellent against Aedes aegypti and Aedes albopictus. Insects. 2021;12(5):386. doi:10.3390/insects12050386 PubChem. Nootkatone. The New York Times. Citrus flavoring is weaponized against insect-borne diseases. Centers for Disease Control and Prevention. Nootkatone: A new active ingredient for developing insecticides and insect repellents. Centers for Disease Control and Prevention. Nootkatone for insecticide and repellent development. Evolva. What is NootkaShield™ nootkatone?. Environmental Protection Agency. Skin-applied repellent ingredients. Centers for Disease Control and Prevention. Illnesses from mosquito, tick, and flea bites increasing in the US. Centers for Disease Control and Prevention. Avoid bug bites.