# How Picaridin Works, and Why Up to 14 Hours Is a Registered Claim > How picaridin works on mosquitoes and ticks, what CDC and EPA say, what cuts any repellent's protection short, and why 14 hours is a registered label claim. Source: https://longsleeve.com/science Longsleeve's up-to-14-hour protection against mosquitoes and ticks was reviewed as part of its EPA registration under Reg. No. 101457-1. This page covers what picaridin does, current CDC guidance, and what affects how long a repellent lasts. **The primary sources are linked at the bottom.** ## How does picaridin work? It works by repelling, not killing. Mosquitoes and ticks locate a host using cues like [the carbon dioxide you exhale, your body heat, and the odor of your skin](https://longsleeve.com/blog/why-mosquitoes-bite-some-people). Picaridin sits on the surface of the skin and interferes with an insect's ability to locate or feed on a host. The exact receptor-level mechanism is still under study. ## What is picaridin? The active, the agency, and what the label says. Picaridin is one of the [active ingredients used in EPA-registered skin-applied repellents](https://longsleeve.com/repellent-index), and the CDC lists it among the ingredients it recommends to help prevent mosquito and tick bites. Longsleeve is EPA Reg. No. 101457-1. Always follow the product label. Longsleeve uses it at 20%, the concentration behind the registered up-to-14-hour claim. [See the tube →](https://longsleeve.com/product) ## What does the registered claim actually say? The number on the tube is the one the EPA reviewed. Up to 14 hours of protection against mosquitoes and ticks, and up to 8 hours against biting flies, stable flies, black flies, gnats, [chiggers](https://longsleeve.com/blog/chigger-bites), sand flies, and [no-see-ums](https://longsleeve.com/blog/no-see-um-bites). That is the claim the EPA reviewed against the submitted efficacy data before the product could be sold. Registration under the federal pesticide law requires efficacy and safety data before a repellent can carry a duration claim. Protection time is a maximum measured under tested conditions, not a guarantee for every situation. How long it lasts in practice depends on the variables below. [Read why we took the long way →](https://longsleeve.com/about) ## What affects protection time? Read the label; these are the variables it accounts for. A repellent only protects the skin it is actually on. A few things change how long a single application holds: - **Coverage.** Apply an even layer to all exposed skin. Gaps are where bites happen. - **Amount.** Too thin a layer protects for less time. - **Sweat, water, and rubbing.** Swimming, heavy sweating, and towel-drying remove repellent early. Reapply according to the label. - **Conditions.** Heat, humidity, and high insect pressure can shorten real-world protection. Follow the product label, including the maximum number of applications per day. ## Does the CDC recommend picaridin? From the CDC and the product label. The CDC lists picaridin among its recommended repellent active ingredients. When applying repellent to children, follow the product label and CDC application guidance. The National Pesticide Information Center's picaridin fact sheet notes that picaridin has low absorption through the skin and summarizes how it is used and studied. Always follow the label. If you have a specific health question, talk to your doctor. ## Sources. Primary sources for what is on this page. Each links out to the original. U.S. Environmental Protection Agency. *Find the Repellent that is Right for You.* Look up an EPA registration number and the ingredients it covers. [epa.gov](https://www.epa.gov/insect-repellents/find-repellent-right-you) Federal regulator · registration lookup U.S. Environmental Protection Agency. *Skin-Applied Repellent Ingredients.* Picaridin is among the active ingredients the EPA registers for skin-applied repellents. [epa.gov](https://www.epa.gov/insect-repellents/skin-applied-repellent-ingredients) Federal regulator · active ingredients Centers for Disease Control and Prevention. *Preventing Mosquito Bites.* Use EPA-registered insect repellents, including picaridin. [cdc.gov](https://www.cdc.gov/mosquitoes/prevention/index.html) CDC · repellent guidance Centers for Disease Control and Prevention, CDC Yellow Book. *Mosquitoes, Ticks & Other Arthropods.* Repellent guidance, including use in children and during pregnancy. [cdc.gov](https://www.cdc.gov/yellow-book/hcp/environmental-hazards-risks/mosquitoes-ticks-and-other-arthropods.html) CDC · pediatric and pregnancy guidance National Pesticide Information Center (Oregon State University, in cooperation with the EPA). *Picaridin General Fact Sheet.* Overview of picaridin, how it is used, and low skin absorption. [npic.orst.edu](https://npic.orst.edu/factsheets/PicaridinGen.html) NPIC · overview and absorption ## Go outside. ### Join the waitlist. Longsleeve is almost here. Drop your email and we'll tell you the day it's available.