Picaridin and DEET are both EPA-registered repellents you put on skin, and neither one kills anything. They interfere with how a mosquito finds you. The practical differences sit elsewhere: DEET is registered from 5 to 99 percent and can damage plastics and some synthetics, while picaridin is nearly odourless and its labels say it leaves plastic alone.
Picaridin vs DEET: two actives, one job, two very different wearing experiences
Almost every comparison of these two is really a comparison of insects: which one holds off a mosquito longer, which one wins on ticks. Useful, up to a point. What it skips is what the stuff does while it sits on your arm for eight hours, and what it does to your sunglasses when you rub your face. So here's the skin-side version, sourced throughout to the EPA, to EPA-accepted labels, and to the National Pesticide Information Center (NPIC).
What each one actually is
DEET is N,N-diethyl-meta-toluamide, developed by the U.S. Army in 1946 and registered for public use in the United States in 1957. The EPA estimates about a third of the U.S. population uses it in a given year, across roughly 120 registered products, in skin-applied formulations running from 5 to 99 percent active ingredient. On mechanism the EPA is refreshingly plain: "Rather than killing them, DEET works by making it hard for these biting bugs to smell us."
Picaridin is younger and stranger. A synthetic compound first made in the 1980s, built to resemble piperine, the molecule that makes black pepper taste like black pepper. The EPA gives its year of initial registration as 2001 under the trade name KBR 3023, and NPIC notes it was already in wide use across Europe and Australia before reaching American shelves in 2005. NPIC describes the mechanism as blocking mosquitoes from sensing their prey, and says flatly that picaridin doesn't kill insects.
Side by side, without the marketing
| Picaridin | DEET | |
|---|---|---|
| What it is | Synthetic, modelled on piperine (black pepper), 1980s | Synthetic amide, U.S. Army, 1946 |
| U.S. registration | Initial registration 2001, on shelves from 2005 | Registered for public use 1957 |
| How it works | Blocks mosquitoes sensing their prey (NPIC) | Makes it hard for biting insects to smell us (EPA) |
| Concentrations | 5%, 7%, 10%, 5.75% wipes at registration; 20% common today | 5% to 99% in registered skin-applied products |
| On-label window | 20% lotion claims up to 14 hours, mosquitoes and ticks | EPA studies: 2 to 10 hours ticks, 2 to 12 hours mosquitoes |
| Odour | Technical grade nearly odourless | Faint odour |
| Skin absorption | Under 6% of what's applied, human studies | Small amount; in blood up to 12 hours |
| Reported skin effects | Irritation, uncommon | Irritation, redness, rash, swelling after long contact |
| Sensitiser | Not a dermal sensitiser (EPA) | Not expected to sensitise with repeat use (NPIC) |
| Plastics, synthetics | 20% label: "Does not damage plastic" | A plasticiser; damages some plastics, vinyl, synthetics |
One row gets misread constantly. Concentration buys you time, not strength: NPIC's wording is that higher concentration repellents may protect for longer, but are not better at keeping insects away. There's a ceiling, too. Products above 50 percent DEET offer no extra protection, the CDC's guidance for anyone choosing DEET is 20 percent or more, and below 10 percent of any active NPIC says you may be looking at one to two hours.
What are the side effects of picaridin?
Uncommon, mostly local, and better documented short-term than long.
NPIC reports that skin irritation from picaridin products happens but is very uncommon, and that it can irritate eyes on contact. The EPA's 2005 assessment found it was not mutagenic and not a dermal sensitiser, and concluded it is not likely to cause cancer based on two-year skin studies in rats and mice. If you came here expecting a safety gap between the two, NPIC's toxicity table rates them identically in every column it scores.
The honest caveat: that picaridin fact sheet carries a review date of December 2009, and NPIC says openly it can't keep every fact sheet current. Read a current product label rather than assume a 2009 document describes the bottle in your hand.
Do you have to wash off picaridin?
Yes, and you have to wash off DEET too. Same answer for both, and most people do neither.
Every DEET label says to wash treated skin with soap and water once you're back indoors, and to wash treated clothing before wearing it again. EPA guidance repeats it for the whole category and adds: not under clothing, never on cuts or irritated or sunburned skin, and spray your hands first rather than spraying at your face.
Picaridin labels are just as specific. The EPA-accepted label for a 20 percent lotion says to apply evenly in a thin layer, not to exceed two applications per day, and to avoid lips, cuts, wounds and irritated skin. Two a day, printed on the bottle. Layering is counterintuitive as well: NPIC records that the CDC does not recommend combined sunscreen and repellent products, and puts sunscreen first, dried, with repellent on top.
Do ticks hate picaridin?
Hate is the wrong verb, and it's why this question keeps getting answered badly.
Nothing here repels by being offensive. Mosquitoes and ticks find you through skin odours, exhaled carbon dioxide, heat, movement and sight, and a repellent interferes with those senses so the insect can't finish the search. NPIC lists ticks and chiggers among the pests picaridin repels, and the EPA-accepted 20 percent lotion claims up to 14 hours against ticks. DEET's tick numbers in EPA's database run roughly 2 to 10 hours by concentration. If ticks are the real reason you're here, note that neither active is what serious tick country puts on fabric. That's permethrin, and it should never go on skin.
The bit nobody tells you until your sunglasses are ruined
DEET is a plasticiser. NPIC's technical fact sheet spells out the consequences: it can damage certain rubber, plastic, vinyl or elastic materials, including contact lenses, eyeglass frames, watch crystals, painted and varnished surfaces, and certain synthetic fabrics. Natural fibres are fine. Cotton and wool don't care. An EPA-accepted DEET label says the same thing in shop language: keep it off acetate, rayon and spandex.
Picaridin's position is the mirror image, and it's an EPA-accepted label claim rather than my opinion. The 20 percent lotion carries "Does not damage plastic" and "Won't Damage Fishing Lines, Plastics or other Synthetic Materials."
Now think about a summer evening. Sunglasses, a watch, a phone case you touch every ten minutes, athleisure that's mostly spandex. That list is a big part of why people who own the strongest DEET in the shop still leave it in the cupboard.
Fragrance, sensitive skin, and reading the list properly
Two things get muddled constantly: the active, and everything else in the bottle. Neither active is expected to sensitise you with repeated use, and reported reactions for both are uncommon. The solvent, the fragrance and the vehicle are a separate question. A repellent is a formulation, not an ingredient, so if your skin has reacted to one before, the active isn't automatically the culprit.
One clarification while we're here, because it derails a lot of shopping. Oil of lemon eucalyptus (OLE) and its refined component PMD are EPA-registered actives with their own registration numbers. Eucalyptus citriodora essential oil, the perfumery ingredient, is not the same thing and is not registered as a repellent active.
The skincare-first alternative, and where it actually sits
There's a third category now, here for completeness rather than as a like-for-like swap: cosmetics formulated with botanicals and worn daily. Misaj, a skincare brand formulated and produced in France, makes Glow Protect, the product that put the idea in front of the beauty press. In the brand's own words on its product page, as of 2 September 2026, it "combines hydration, skin barrier support and botanical mosquito protection in a single cream designed to be worn daily," with "a natural aromatic blend that helps deter mosquitoes."
Glow Protect is an EU skincare cream, sold at 100 ml for 38 euros and built around a botanical aromatic blend for daily wear. It is sold as a skincare product rather than as a registered repellent. The brand does publish its full INCI list on the page, which is the useful part for reactive skin: you can read the fragrance components (citronellol, linalool, geraniol, eugenol, limonene and coumarin among them) before you buy rather than after.
When a conventional repellent is the right call
Plainly, because a skincare-adjacent article rarely says it.
If you're going somewhere mosquito-borne or tick-borne illness is a genuine concern, that decision belongs to a pharmacist, a doctor and the public health guidance for the destination. Not to a blog post, and not to a cosmetic. The EPA's own framing of DEET's benefit is exactly this: repelling potentially disease-carrying insects and ticks. Same answer for children and pregnancy.
If you need long, unbroken coverage in hostile conditions, buy the registered product, take the smell, and keep it off your sunglasses. Look for an EPA registration number, which is why the CDC points people toward registered products in the first place.
You can see the formulation and the full ingredient list on the Glow Protect product page. For more on the skincare-first angle, see what an anti-mosquito moisturiser actually is and what smell mosquitoes actually hate in the misaj journal.
Frequently asked questions
What are the side effects of picaridin?
NPIC reports that skin irritation from picaridin products happens but is very uncommon, and that it can irritate eyes on contact. The EPA's 2005 assessment found it is not a dermal sensitiser and concluded it is not likely to cause cancer, based on two-year skin studies in rats and mice.
Do you have to wash off picaridin?
Yes. EPA guidance for skin-applied repellents is to wash skin with soap and water once you're back indoors, and to wash clothing before wearing it again. The EPA-accepted label for a 20 percent picaridin lotion also caps use at two applications a day.
Do ticks hate picaridin?
Not hate, exactly. Repellents interfere with how ticks and mosquitoes locate a host rather than repelling by smell alone. NPIC lists ticks and chiggers among the pests picaridin repels, and an EPA-accepted 20 percent lotion claims up to 14 hours against ticks. For clothing and gear, permethrin is the usual answer, and it should never go on skin.
Sources (every one fetched 2026-09-02)
- EPA, DEET. Page states "Last updated on May 27, 2026". https://www.epa.gov/insect-repellents/deet
- EPA, Skin-Applied Repellent Ingredients. Page states "Last updated on January 23, 2026". https://www.epa.gov/insect-repellents/skin-applied-repellent-ingredients
- EPA, Using Insect Repellents Safely and Effectively. https://www.epa.gov/insect-repellents/using-insect-repellents-safely-and-effectively
- EPA, New Pesticide Fact Sheet: Picaridin, May 2005 (year of initial registration 2001, trade name KBR 3023, "not a dermal sensitizer", registered formulation list). https://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-070705_01-May-05.pdf
- EPA-accepted label, Insect Guard 3023 Insect Repellent Lotion, 20% picaridin, EPA Reg. No. 54287-23, PRN 98-10 notification accepted 15 February 2022 (14-hour and 8-hour claims, "Does not damage plastic", two-applications-per-day direction). https://www3.epa.gov/pesticides/chem_search/ppls/054287-00023-20220215.pdf
- EPA-accepted label, REPEL 25, EPA Reg. No. 305-51, 24 June 2009 (acetate, rayon and spandex restriction; leather, plastics and varnish warnings). https://www3.epa.gov/pesticides/chem_search/ppls/000305-00051-20090624.pdf
- EPA, R.E.D. FACTS: DEET, EPA-738-F-95-010, April 1998 (1946 development, 1957 registration). https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-080301_1-Apr-98.pdf
- NPIC, Picaridin General Fact Sheet, review date December 2009. https://npic.orst.edu/factsheets/PicaridinGen.html
- NPIC, DEET General Fact Sheet, review date July 2008. https://npic.orst.edu/factsheets/DEETgen.html
- NPIC, DEET Technical Fact Sheet, review date July 2008 (the plasticiser passage). https://npic.orst.edu/factsheets/archive/DEETtech.html
- NPIC, Insect Repellents Fact Sheet, review date February 2018 (toxicity table, concentration and duration guidance, sunscreen layering, CDC positions). https://npic.orst.edu/factsheets/repellents.html
- misajskin.com, Glow Protect product page (price, size, quoted brand wording, full INCI). https://misajskin.com/products/glow-protect
Note on source age, stated in the article itself: the two NPIC single-ingredient fact sheets carry review dates of 2008 and 2009, and NPIC says openly that it cannot keep every fact sheet current. The EPA pages and the accepted product labels are the newer half of this list, and the concentration and duration figures come from those.