Written and medically reviewed by Dr. Diane Mueller, ND, LAc, DAOM, founder of MyLymeDoc. Last reviewed September 10, 2026.
If you live somewhere ticks are a fact of summer, you have probably stood in an aisle reading two labels that both promise protection and wondered which one is telling the truth. Here is what the evidence supports.
The strongest evidence for preventing tick bites belongs to permethrin applied to clothing and gear, which outperforms every skin-applied option in the published tick data. In a double-blind randomized trial of outdoor workers, permethrin-treated uniforms were 82% effective against tick bites in the first year, with a confidence interval of 66% to 91%. For skin-applied repellents, the EPA registers eight active ingredients for skin, including DEET, picaridin, IR3535 and oil of lemon eucalyptus, and publishes typical protection times rather than any ranking of which works best. The uncomfortable part is that field data specifically testing skin repellents against blacklegged tick bites is thin.
Choosing the best tick repellent comes down to one distinction that is easy to miss: skin repellents and clothing treatments work differently, against different parts of the problem. That distinction is the whole subject, so start there. If you are not sure which ticks you are guarding against, our tick identification guide is the place to begin.
Repellents divide into skin-applied products and clothing treatments, and they work by different mechanisms against different parts of the problem. Confusing them is the mistake that changes what people do with the product.
Permethrin is a synthetic insecticide for treating fabric. Treated clothing stays protective through several washings.
Picaridin, also written icaridin, is a synthetic repellent derived from a compound in pepper plants, marketed as a lower-odor alternative to DEET.
Skin repellents go on exposed skin and interfere with a tick’s ability to locate you, and they are only half the answer for anyone in tick habitat. The EPA lists eight registered active ingredients for skin: catnip oil, oil of citronella, DEET, IR3535, para-menthane-diol, oil of lemon eucalyptus, picaridin, and 2-undecanone. The EPA does not publish any ranking of these eight by effectiveness, and its own repellent search tool carries the caveat that “there are variations in the resulting protection times because of differences in the testing conditions.”
Permethrin belongs to the other category entirely. It is applied to clothing, boots and gear, and CDC notes it can “remain protective through several washings.” The only skin-applied permethrin products are prescription treatments for scabies and head lice, a different formulation for a different purpose. Knowing which ticks carry Lyme disease where you live tells you how much any of this matters.
Permethrin acts as a contact toxicant, meaning ticks still climb onto treated fabric and are then disabled by it. Describing it as repelling ticks misdescribes what happens, and leads people to trust it in the wrong way.
Research on blacklegged ticks found that “permethrin-treated textile appears to have minimal non-contact spatial repellency for I. scapularis.” The ticks do not sense the treated fabric from a distance and turn away. They make contact, absorb the compound, and lose motor function. In the same work, at one hour after exposure fewer than 5% of ticks displayed normal movement.
The practical implication changes behavior. Since ticks reach the fabric before the treatment does anything, checking yourself thoroughly still matters on a day you wore treated clothing. A disabled tick on your sock is a tick that was on you.
Permethrin-treated clothing has the best evidence of any tick prevention measure, and that evidence has a one-year shelf life.
Researchers ran a double-blind randomized trial with outdoor workers in North Carolina, following 159 randomized participants across more than 5,000 person-weeks and recording 1,045 work-related tick bites. Effectiveness of the treated uniforms was 0.82, with a 95% confidence interval of 0.66 to 0.91, in year one. Only 101 of the 159 completed year two, so the wide second-year interval reflects a smaller sample as well as a smaller effect. In year two it fell to 0.34 with a confidence interval of negative 0.67 to 0.74. A confidence interval spanning zero means the year-two result cannot be distinguished from no effect. The authors concluded the uniforms were “highly effective for at least 1 year in deterring tick bites,” and that qualifier is doing real work.
If you bought factory-treated clothing two seasons ago and have relied on it since, that is the finding to act on. Retreat annually or buy fresh. Our page on keeping ticks away shares proven ways on how to stay safe outdoors.
Footwear. That is what the number describes, not head-to-toe protection. The qualifier is easy to lose when the number travels, and the same study also reports the whole-outfit figure.
In a controlled study using 15 volunteers and pathogen-free nymphal blacklegged ticks, “subjects wearing permethrin-treated sneakers and socks were 73.6 times less likely to have a tick bite.” In the same experiment, “subjects wearing outfits treated with permethrin received 3.36 times fewer tick bites than subjects wearing untreated outfits.” Both numbers are real, they measure different things, and 3.36 is the one that describes wearing treated clothes.
One caveat belongs with the footwear result. In that study the ticks were placed by hand on the shoe, leg and arm, so it reflects a controlled infestation rather than field questing behavior. Ticks do climb from ground level, which makes footwear a sensible priority, but 73.6 should not be read as a field estimate.
Most of what gets said about skin repellents and ticks is extrapolated from mosquito research. A clinician who treats tick-borne illness should say that out loud, even though it complicates the shopping decision.
A 2016 review of tick repellent evidence noted that published field data for skin-applied repellents protecting against tick bites “are unfortunately lacking for I. scapularis,” the species responsible for Lyme disease in most of the United States. The same sentence continues that European data for Ixodes ricinus “suggest that protection is in the range of 40-65% for deet and lemon eucalyptus extract,” which is a different tick on a different continent but the closest figure that exists.
This is also why this page does not rank picaridin against DEET for tick protection. No peer-reviewed field data comparing them specifically on blacklegged tick bites turned up in this review. Both are EPA-registered, both have tick claims on properly labeled products, and anyone presenting a confident hierarchy between them is going beyond what has been published.
| Active | EPA-registered for skin | Tick-specific evidence | Age limits |
|---|---|---|---|
| DEET | Yes, more than 500 products | Most widely used. Field trials recovering attached I. scapularis are lacking | AAP publishes concentration guidance for children |
| Picaridin | Yes, about 40 products | No peer-reviewed blacklegged-tick field data located | None specific to ticks |
| IR3535, 2-undecanone, catnip oil, oil of citronella | Yes, about 45 / 1 / 4 / 3 products | Limited tick-specific published data | None specific to ticks |
| Oil of lemon eucalyptus, PMD | Yes, 6 products each | Limited tick-specific published data | Not for children under 3 (CDC) |
| Permethrin (fabric only) | Fabric and gear only | Strongest: 82% in a randomized trial year one, and >95% for treated military clothing | Fabric and gear only |
Read the third column twice. It is why this page declines to crown a single best skin repellent: the comparative tick data has not been published.
The EPA repellency graphic names which pests a product was tested against, and using it is voluntary, so plenty of effective products do not carry it.
The EPA explains that “you may see one of three versions of the graphic on a product label showing that mosquitoes, ticks, or mosquitoes AND ticks are repelled.” It adds that “the number(s) shown in the graphic represent typical protection time(s).” If the graphic on the bottle shows a mosquito and no tick, the tick claim was not part of what EPA reviewed for that graphic. Because participation is voluntary, a bottle with no graphic at all tells you nothing, and you should read the label’s pest list instead.
On concentration, the figures repeated across the internet as EPA guidance actually come from the American Academy of Pediatrics. Concentration governs duration rather than strength, so match it to how long you will be outside.
Two restrictions catch people out: an age limit on oil of lemon eucalyptus, and permethrin’s effect on cats.
CDC states directly: “do not use products containing OLE or PMD on children under 3 years old.” EPA lists oil of lemon eucalyptus and p-menthane-3,8-diol as two separate registered actives. Of oil of lemon eucalyptus, EPA notes that it “contains pmd, but is a separately regulated pesticide chemical.” Registered repellent products are not the same thing as lemon eucalyptus essential oil sold on a health store shelf, which has never been through EPA review.
For households with cats, the National Pesticide Information Center explains that “cats are more sensitive to permethrin than dogs or people because it takes their bodies a long time to break it down.” Follow the product label on drying time and keep cats away from treated items until the label conditions are met.
Repellents have reasonable evidence for reducing bites and inconsistent evidence for reducing tick-borne disease. Those are separate outcomes and the gap between them deserves an honest answer.
A 2022 review of personal protection measures concluded that “the results are mixed for each personal protection measure, with some studies indicating that regular use of the measure is associated with a reduction in tick-borne disease while other studies found no similar protective effect.” That is the current state of the science, and it should raise your commitment to the other layers rather than lower it.
A nymph is the immature stage of a tick, about the size of a poppy seed, and the stage responsible for most Lyme transmission precisely because it is so easy to miss.
Part of the reason is size. The same review notes that nymphal blacklegged ticks are assumed responsible for most bites in the 30 to 50% of US Lyme disease cases where the patient never knew they had been bitten. The bite that infects you is frequently the one you never see, which makes checking for ticks properly at least as important as what you sprayed on beforehand.
Prompt removal is a prevention measure in its own right, because transmission takes time. Every repellent strategy needs this backstop.
CDC advises that in most cases a tick must be attached for more than 24 hours before the Lyme disease bacterium is transmitted. You will still see “36 to 48 hours” repeated widely, including on pages that have not been updated, so working from the shorter window is the safer habit. Our guide to removing a tick safely covers the technique.
Then watch, and note the date. It helps to know in advance what a normal bite reaction looks like compared with Lyme.
In our practice we would rather see someone early with a bite that turns out to be nothing. And if you’re concerned it might be a blacklegged tick, our page on preventing Lyme after a tick bite has the information you need to know in the 72-hour period after a tick bite.
If you are unsure what you are looking at, talk to someone who treats tick-borne illness rather than waiting.
The American Academy of Pediatrics provides concentration guidance for children, noting 10% DEET protects for about 2 hours and 30% for about 5 hours. Oil of lemon eucalyptus and PMD carry a firmer restriction: CDC advises against using them on children under 3 years old. Ask your child’s doctor about your specific situation.
Two plant-derived actives are EPA-registered, catnip oil and oil of citronella, alongside para-menthane-diol which is refined from lemon eucalyptus. EPA registers oil of lemon eucalyptus separately from PMD itself. Neither registration covers essential oil sold as a wellness product. Homemade essential oil sprays have not been through EPA efficacy review.
It reduces the chance of being bitten, which reduces risk, but the evidence connecting repellent use to lower rates of tick-borne disease is mixed rather than settled. Repellent is one layer. Body checks, prompt removal, and treating clothing are the others, and the layered approach matters because most people who get Lyme never noticed the bite.
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