DEET vs PMD

The same eleven questions, side by side, each answer in the agency's words. No verdict from us: we sell a product built on one of these actives, so the agencies do the talking.

DEETN,N-diethyl-meta-toluamide

PMDp-menthane-3,8-diol

Per EPA's tool

DEET

Registered; 505 products in EPA's tool; 2 to 12 h mosquitoes, 2 to 10 h ticks.

PMD

Registered; 8 products in EPA's tool; 2 h mosquitoes, 2 h ticks.

What is it, and where does it come from?

DEET

EPA says DEET, made for skin, works by making it hard for biting bugs to smell us.

Source and detail: EPA

DEET, N,N-diethyl-meta-toluamide, is what EPA's DEET page calls the active ingredient in many repellent products, designed for direct application to people's skin. EPA says it was developed by the U.S. Army in 1946 and registered for use by the general public in 1957, and that rather than killing biting bugs it works by making it hard for them to smell us.

DEET (chemical name, N,N-diethyl-meta-toluamide) is the active ingredient in many repellent products. It is widely used to repel biting pests such as mosquitoes and ticks. Every year, an estimated one-third of the U.S. population use DEET to protect them from mosquito-borne illnesses like West Nile Virus, the Zika virus or malaria and tick-borne illnesses like Lyme disease and Rocky Mountain spotted fever.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

DEET is designed for direct application to people's skin to repel insects. Rather than killing them, DEET works by making it hard for these biting bugs to smell us. After it was developed by the U.S. Army in 1946, DEET was registered for use by the general public in 1957. Approximately 120 products containing DEET are currently registered with EPA by about 30 different companies.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

PMD

EPA calls it a biochemical pesticide derived from eucalyptus plants, chemically synthesized for commercial use.

Source and detail: Carroll SP, US EPA

p-Menthane-3,8-diol occurs naturally in the lemon eucalyptus plant, the natural oil can be extracted from the leaves and twigs, and for commercial use the active ingredient is chemically synthesized, per EPA's April 2000 fact sheet, which calls it a biochemical pesticide derived from eucalyptus plants. Carroll and Loye, Journal of the American Mosquito Control Association, 2006, describe PMD as a monoterpene spent product of distilling leaves of the Australian lemon-scented gum tree, Corymbia citriodora.

p-Menthane-3,8-diol occurs naturally in the lemon eucalyptus plant. The natural oil can be extracted from the eucalyptus leaves and twigs. For commercial use, the active ingredient is chemically synthesized.
US EPA, p-Menthane-3,8-diol (011550) Fact Sheet, April 2000

p- Menthane-3,8-diol is a biochemical pesticide derived from eucalyptus plants. This active ingredient is used to make products that are applied to human skin and clothing for the purpose of repelling insects, such as mosquitoes.
US EPA, p-Menthane-3,8-diol (011550) Fact Sheet, April 2000

para-Menthane-3,8-diol(PMD) is a monoterpene spent product of the distillation of leaves of the Australian lemon-scented gum tree (updated nomenclature Corymbia citriodora ssp. citriodora).
Carroll SP, Loye J. PMD, a registered botanical mosquito repellent with deet-like efficacy. J Am Mosq Control Assoc. 2006;22(3):507-14. PMID 17067054

How does EPA treat it?

DEET

Registered, about 120 products per EPA; its 1998 review found repellents containing DEET present no health concern.

Source and detail: EPA

Registered: EPA's DEET page says approximately 120 products containing DEET are registered with EPA by about 30 companies. EPA's 1998 reregistration decision concluded that insect repellents containing DEET do not present a health concern; its registration review risk assessment found no risks of concern because no toxic effects have been identified when it is used as a dermally applied insect repellent, with a final decision waiting on Endocrine Disruptor Screening.

DEET is designed for direct application to people's skin to repel insects. Rather than killing them, DEET works by making it hard for these biting bugs to smell us. After it was developed by the U.S. Army in 1946, DEET was registered for use by the general public in 1957. Approximately 120 products containing DEET are currently registered with EPA by about 30 different companies.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

After completing a comprehensive re-assessment of DEET, we concluded that insect repellents containing DEET do not present a health concern. Consumers are advised to read and follow label directions when using any pesticide product, including insect repellents. Based on extensive toxicity testing, we believe that the normal use of DEET does not present a health concern to the general population, including children. We completed this review and issued a reregistration decision (called a RED) in 1998.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

The human health risk assessment concluded that there are no risks of concern because no toxic effects have been identified when used as a dermally applied insect repellent, and there is no dietary or occupational exposure for DEET. However, a Final Decision on the DEET registration review case will occur only after the EPA has completed an Endocrine Disruptor Screening under FFDCA section 408(p).
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

PMD

Registered since March 2000, EPA says; its ingredients page now counts 6 products under PMD.

Source and detail: US EPA

Registered in March 2000, licensed for sale with a consumer spray registered at the same time, per EPA's fact sheet; EPA's skin-applied ingredients page now counts 6 products under p-menthane-3,8-diol, listed separately from oil of lemon eucalyptus. EPA says registrants of products used against public health pests must show specific standards for effectiveness and safety are met, and that the registered PMD product met them.

p-Menthane-3,8-diol was registered (licensed for sale) in March 2000. A consumer spray product was registered at the same time.
US EPA, p-Menthane-3,8-diol (011550) Fact Sheet, April 2000

p-Menthane-3,8-diol (pmd) -- EPA pesticide regulatory information (6 products)
US EPA, Skin-Applied Repellent Ingredients, last updated January 23, 2026

Oil of Lemon Eucalyptus (contains pmd, but is a separately regulated pesticide chemical) (6 products)
US EPA, Skin-Applied Repellent Ingredients, last updated January 23, 2026

EPA requires registrants of products used against public health pests to show that the product meets specific standards for effectiveness as well as for safety. EPA considers a public health pest as any organism that can cause or transmit human disease, or can cause human discomfort or injury. Examples include fleas, mosquitoes, ticks, and certain rodents. The product currently registered with p-Menthane-3,8-diol for use against public health pests has met the required standards.
US EPA, p-Menthane-3,8-diol (011550) Fact Sheet, April 2000

What strengths are registered, and does strength change protection?

DEET

EPA registers 5 to 99%; CDC says higher concentrations generally protect longer, with DEET peaking near 50%.

Source and detail: CDC Yellow Book, EPA

EPA's DEET page says formulations registered for direct application to human skin contain from 5 to 99 percent DEET. CDC's Yellow Book says higher concentrations generally provide longer protection regardless of the active ingredient, and that studies suggest DEET efficacy tends to peak at approximately 50 percent, with concentrations above that not offering a marked increase in protection time against mosquitoes.

Products containing DEET currently are available to the public in a variety of liquids, lotions, sprays, and impregnated materials (e.g., towelettes, roll on). Formulations registered for direct application to human skin contain from 5 to 99% DEET.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

In general, higher concentrations of active ingredients provide longer duration of protection, regardless of the active ingredient. Products with <10% active ingredient might offer only limited protection, often 1-2 hours. Products that offer sustained-release or controlled-release (microencapsulated) formulations, even with lower active ingredient concentrations, might provide longer protection times. Studies suggest that DEET efficacy tends to peak at a concentration of approximately 50% and that concentrations above that do not offer a marked increase in protection time against mosquitoes.
CDC Yellow Book, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture 2026-09-19)

PMD

10 percent on the record: a label states 10 percent, and EPA's tool lists a 10 percent product.

Source and detail: NPIC, US EPA, US EPA accepted label

10 percent is the registered strength on the record: the EPA-accepted label for EPA Reg. No. 4822-528 states p-menthane-3,8-diol at 10 percent, and EPA's search tool lists a 10 percent PMD product. NPIC's fact sheet says repellents with less than 10 percent active ingredient may only protect for 1 to 2 hours, and that higher concentrations may protect longer without being better at keeping insects away.

ACTIVE INGREDIENT: p-Menthane-3,8-diol* 10%
US EPA accepted label, Claire-1 / OFF! Botanicals Insect Repellent I, EPA Reg. No. 4822-528, dated 1/31/14

OFF! Botanicals Insect Repellent | 2 | 2 | p-Menthane-3,8-diol | 10 | S.C. Johnson & Son, Inc. | 4822-515
US EPA, Find the Repellent that is Right for You, search results application, fetched 2026-09-22

Higher concentration repellents may protect people for longer. However, they are not better at keeping insects away. 5,6,7 Repellents with less than 10% of an active ingredient may only offer protection for short periods of time (1-2 hours).
NPIC, Insect Repellents Fact Sheet, Oregon State University Extension Services, date reviewed February 2018

How long does EPA say it protects?

DEET

EPA says 2 to 12 hours for mosquitoes and 2 to 10 for ticks, depending on the percentage.

Source and detail: EPA, U.S. EPA

EPA's DEET page says studies in its database indicate DEET repels ticks for about two to ten hours and mosquitoes from two to twelve hours, depending on the percentage of DEET in the product. In EPA's repellent search tool, Ben's 100 Insect Repellent, EPA Reg. No. 56575-7, at 98.11 percent DEET, lists 10 hours for mosquitoes and 10 for ticks. EPA says protection times vary because testing conditions differ, and that the tool's database was last updated in June 2019.

Studies in EPA's database indicate that DEET repels ticks for about two to ten hours, and mosquitoes from two to twelve hours depending on the percentage of DEET in the product.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

Ben's 100 Insect Repellent | 10 | 10 | DEET | 98.11 | Tender Corp. | 56575-7
EPA, Find the Repellent that is Right for You, search results for DEET, cfpub.epa.gov/oppref/insect_s

While this technical information is based on scientific testing guidelines and approved study methods, there are variations in the resulting protection times because of differences in the testing conditions.
EPA, Find the Repellent that is Right for You

Any products listed are for informational purposes only. Inclusion of a product listed/referenced is not an endorsement. * EPA and the U.S. Government do not endorse any product or service. * The information in this database was last updated in June 2019.
U.S. EPA, Find the Repellent that is Right for You

PMD

EPA's tool lists 2 hours for mosquitoes and 2 for ticks at 10 percent.

Source and detail: US EPA

2 hours for mosquitoes and 2 hours for ticks: EPA's search tool lists a 10 percent p-menthane-3,8-diol product, EPA Reg. No. 4822-515, at 2 and 2. EPA says those times were approved for product labels from technical information the company provided, and that the tool's database was last updated in June 2019.

OFF! Botanicals Insect Repellent | 2 | 2 | p-Menthane-3,8-diol | 10 | S.C. Johnson & Son, Inc. | 4822-515
US EPA, Find the Repellent that is Right for You, search results application, fetched 2026-09-22

Protection Times - These protection times have been approved for product labels. These times are based on the technical information provided by the company on the effectiveness of the product against mosquitoes and/or ticks.
US EPA, Find the Repellent that is Right for You, search results application, fetched 2026-09-22

The registration number means the company provided EPA with technical information on the safety of the product and its effectiveness against mosquitoes and/or ticks. While this technical information is based on scientific testing guidelines and approved study methods, there are variations in the resulting protection times because of differences in the testing conditions.
US EPA, Find the Repellent that is Right for You, last updated September 8, 2026

The information in this database was last updated in June 2019.
US EPA, Find the Repellent that is Right for You, last updated September 8, 2026

Which pests do accepted labels name, and what does CDC say those pests carry?

DEET

A 15% label names mosquitoes, gnats, no-see-ums, biting flies, ticks, chiggers and fleas.

Source and detail: EPA notification label

The accepted label for a 15 percent DEET aerosol, EPA Reg. No. 4822-380, claims protection from mosquitoes, gnats, no-see-ums, biting flies, ticks, chiggers and fleas. On ticks, the label's exact wording is "including ticks that may cause Lyme disease."

EFFECTIVE PROTECTION from Mosquitoes, Gnats, No-See-Ums, Biting Flies, Ticks (including ticks that may cause Lyme disease), Chiggers and Fleas
EPA notification label, OFF! Insect Repellent II, EPA Reg. No. 4822-380, 15% DEET aerosol, November 13, 2009

PMD

A label names mosquitoes, black flies, gnats, no-see-ums and ticks.

Source and detail: US EPA, US EPA accepted label

Mosquitoes, black flies, gnats, no-see-ums and ticks: the EPA-accepted label for EPA Reg. No. 4822-528 permits the optional claim that the product repels mosquitoes, black flies, gnats, no-see-ums and ticks for up to 2 hours. EPA's fact sheet describes PMD products as applied to human skin and clothing to repel insects such as mosquitoes.

Repels (mosquitoes) (,black flies, gnats, no-see-ums and ticks) (up to 2 hours)
US EPA accepted label, Claire-1 / OFF! Botanicals Insect Repellent I, EPA Reg. No. 4822-528, optional marketing language, dated 1/31/14

p- Menthane-3,8-diol is a biochemical pesticide derived from eucalyptus plants. This active ingredient is used to make products that are applied to human skin and clothing for the purpose of repelling insects, such as mosquitoes.
US EPA, p-Menthane-3,8-diol (011550) Fact Sheet, April 2000

What do the agencies say about children?

DEET

No age limit, EPA and CDC say, and EPA sets no percentage limit for children.

Source and detail: CDC Yellow Book, EPA

EPA's DEET page states that DEET "is approved for use on children with no age restriction," and that there is no restriction on the percentage of DEET in a product for use on children, since registration tests showed no difference in effects between young and adult animals. CDC's Yellow Book says insect repellents containing DEET, picaridin, IR3535 and 2-undecanone can be used on children without age restriction.

DEET is approved for use on children with no age restriction. There is no restriction on the percentage of DEET in the product for use on children, since data do not show any difference in effects between young animals and adult animals in tests done for product registration.
EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

Insect repellents containing DEET, picaridin, IR3535, and 2-undecanone can be used on children without age restriction
CDC Yellow Book, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture 2026-09-19)

PMD

Not under 3, CDC and a label both say; the label adds children must not apply it themselves.

Source and detail: CDC Travelers' Health, US EPA accepted label

Not under three. CDC says not to use products containing oil of lemon eucalyptus or para-menthane-diol on children under 3 years old, and the EPA-accepted label for EPA Reg. No. 4822-528 carries the precautionary statement not to use the product on children under the age of three, and not to let children apply it to themselves.

Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children under 3 years old.
CDC Travelers' Health, Avoid Bug Bites

CAUTION: May be harmful if swallowed. Causes moderate eye irritation. Avoid contact with eyes. Do not use on children under the age of three. Do not allow children to apply this product to themselves.
US EPA accepted label, Claire-1 / OFF! Botanicals Insect Repellent I, EPA Reg. No. 4822-528, 10% p-Menthane-3,8-diol liquid, dated 1/31/14

What do CDC and WHO say about pregnancy?

DEET

CDC lists it for pregnant and breastfeeding women; one 897-woman trial found no adverse effects to one year.

Source and detail: CDC, McGready R

CDC's Preventing Mosquito Bites page lists DEET among the active ingredients it names, and says that when used as directed, EPA-registered insect repellents are "proven safe and effective, even for pregnant and breastfeeding women." McGready 2001, a double-blind randomized trial of 897 women, found no adverse neurologic, gastrointestinal or dermatologic effects from daily DEET in the second and third trimesters, and none on survival, growth or development at birth or one year.

Use EPA-registered insect repellents with one of the following active ingredients. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.
CDC, Preventing Mosquito Bites (Wayback Machine capture 2026-09-16)

When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. DEET Picaridin (known as KBR 3023 and icaridin outside the United States)
CDC, Preventing Mosquito Bites (Wayback Machine capture 2026-09-16)

The safety of daily application of N, N-diethyl-m-toluamide (DEET) (1.7 g of DEET/day) in the second and third trimesters of pregnancy was assessed as part of a double-blind, randomized, therapeutic trial of insect repellents for the prevention of malaria in pregnancy (n = 897). No adverse neurologic, gastrointestinal, or dermatologic effects were observed for women who applied a median total dose of 214.2 g of DEET per pregnancy (range = 0-345.1 g).
McGready R, et al. Safety of the insect repellent N,N-diethyl-M-toluamide (DEET) in pregnancy. Am J Trop Med Hyg. 2001 Oct;65(4):285-9. PMID 11693870

DEET crossed the placenta and was detected in 8% (95% confidence interval = 2.6-18.2) of cord blood samples from a randomly selected subgroup of DEET users (n = 50). No adverse effects on survival, growth, or development at birth, or at one year, were found. This is the first study to document the safety of DEET applied regularly in the second and third trimesters of pregnancy.
McGready R, et al. Am J Trop Med Hyg. 2001 Oct;65(4):285-9. PMID 11693870

PMD

CDC lists it for pregnant and breastfeeding women; no PMD-specific pregnancy finding from CDC, WHO or EPA.

Source and detail: CDC Travelers' Health

CDC says that when used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women, and para-menthane-diol is on the list of actives to which CDC attaches that statement. No PMD-specific pregnancy finding from CDC, WHO or EPA was among the sources read.

When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. If also using sunscreen, always apply insect repellent after sunscreen. DEET Picaridin (known as KBR 3023 and icaridin outside the US) IR3535 Oil of lemon eucalyptus (OLE) Para-menthane-diol (PMD) 2-undecanone
CDC Travelers' Health, Avoid Bug Bites

What do NPIC and EPA report about absorption and toxicity?

DEET

NPIC says a small amount absorbs through skin; EPA calls it generally low in acute toxicity.

Source and detail: EPA, NPIC

NPIC says a small amount of DEET applied to skin is taken into the body, more when alcohol is also on the skin. EPA's 1998 R.E.D. FACTS sheet calls DEET generally of low acute toxicity and a Group D carcinogen, not classifiable as a human carcinogen. EPA's 1998 reregistration decision counted 14 seizure cases since 1960, including four deaths, potentially related to DEET: an observed incidence of about one recognized seizure per 100 million users each year.

When DEET was applied to the skin of volunteers by researchers, they found that a small amount of the DEET was taken into the body through the skin. When DEET and alcohol are applied to the skin, more DEET is taken into the skin compared with DEET alone. Drinking alcohol may also cause more DEET to be absorbed through the skin. Sunscreen products that contain DEET may cause more DEET to be taken into the body through the skin.
NPIC, DEET General Fact Sheet

DEET generally is of low acute toxicity, and, based on the available toxicological data, the Agency believes that the normal use of DEET does not present a health concern to the general U.S. population (the Agency's human risk assessment has identified no toxicologically significant effects in animal studies.) DEET has been classified as a Group D carcinogen (not classifiable as a human carcinogen.)
EPA, R.E.D. FACTS: DEET, EPA-738-F-95-010, April 1998

In summary, since 1960, there have been 14 cases of seizure, including four deaths, potentially related to DEET exposure, for which other more likely causes have not been identified. An additional 32 cases of seizure reported to the national DEET registry are currently under review.
EPA, Reregistration Eligibility Decision (RED) DEET, EPA738-R-98-010, approved April 13, 1998

people using DEET each year, the observed incidence of recognized seizures is about one per 100 million users.
EPA, Reregistration Eligibility Decision (RED) DEET, EPA738-R-98-010, approved April 13, 1998

PMD

EPA says animal studies showed only eye irritation; a label warns it may be harmful if swallowed.

Source and detail: NPIC, US EPA, US EPA accepted label

In laboratory animal studies p-menthane-3,8-diol showed no adverse effects except eye irritation, EPA's fact sheet says, and special precautions were put on the label to keep the product out of eyes. The accepted label for EPA Reg. No. 4822-528 reads CAUTION, may be harmful if swallowed, causes moderate eye irritation. NPIC says about 3 to 19 percent of a repellent applied to skin may be absorbed into the body.

In studies using laboratory animals, p-Menthane-3,8-diol shows no adverse effects except for eye irritation. Therefore, special precautions were put on the label to prevent the product from contacting people's eyes.
US EPA, p-Menthane-3,8-diol (011550) Fact Sheet, April 2000

CAUTION: May be harmful if swallowed. Causes moderate eye irritation. Avoid contact with eyes. Do not use on children under the age of three. Do not allow children to apply this product to themselves.
US EPA accepted label, Claire-1 / OFF! Botanicals Insect Repellent I, EPA Reg. No. 4822-528, 10% p-Menthane-3,8-diol liquid, dated 1/31/14

When a repellent is applied to skin, about 3-19% may be absorbed into the body.
NPIC, Insect Repellents Fact Sheet, Oregon State University Extension Services, date reviewed February 2018

Does it damage plastics, fabrics or gear?

DEET

NPIC says it can damage certain plastics, rubber, vinyl and synthetics; a label spares nylon, cotton and wool.

Source and detail: EPA amended reregistration label, NPIC

NPIC's DEET technical fact sheet calls DEET a plasticizer that can damage certain rubber, plastic, vinyl or elastic materials, including contact lenses, eyeglass frames and lenses, watch crystals, combs, painted and varnished surfaces, and certain synthetic or treated fabrics. The accepted label for a 10 percent DEET product, EPA Reg. No. 121-53, says it will not damage nylon, cotton or wool.

DEET is a plasticizer and can damage certain rubber, plastic, vinyl, or elastic materials such as contact lenses, eyeglass frames and lenses, watch crystals, combs, painted and varnished surfaces, and certain synthetic or treated fabrics.
NPIC, DEET Technical Fact Sheet (archived)

Will not damage nylon, cotton, or wool.
EPA amended reregistration label, Cutter Insect Repellent #10GE, EPA Reg. No. 121-53, 10% DEET, March 18, 2009

PMD

Spandex is the one material named: a label says do not apply on or around spandex.

Source and detail: US EPA accepted label

Spandex is the one material named: the EPA-accepted label for EPA Reg. No. 4822-528 instructs users not to apply the product on or around spandex. No agency statement about PMD and plastics or other gear was among the sources read.

Do not apply on or around spandex.
US EPA accepted label, Claire-1 / OFF! Botanicals Insect Repellent I, EPA Reg. No. 4822-528, 10% p-Menthane-3,8-diol liquid, dated 1/31/14

What do the agencies say about pets?

DEET

EPA lists cats, dogs and horses as use sites; nothing on pets unless the label says so.

Source and detail: EPA, NPIC

EPA's 1998 R.E.D. FACTS sheet lists cats, dogs, horses and pet living and sleeping quarters among DEET's use sites. EPA tells consumers not to use any product on pets unless the label clearly states it is for animals. NPIC says reports of pets exposed to DEET in amounts that would make them sick are rare; overexposed pets have shown vomiting, shaking, excitement, lack of coordination and seizures.

N,N-diethyl-meta-toluamide (DEET) is an insect repellent used in households/domestic dwellings, on the human body and clothing being worn, on cats, dogs, horses and pet living/sleeping quarters. There are no food uses.
EPA, R.E.D. FACTS: DEET, EPA-738-F-95-010, April 1998

Do not use any product on pets or other animals unless the label clearly states it is for animals.
EPA, Using Insect Repellents Safely and Effectively

Reports of pets being exposed to DEET in amounts that would make them sick are rare. Pets that have been overexposed to DEET have shown varying effects, including vomiting, shaking, excitement, lack of coordination, and seizures.
NPIC, DEET General Fact Sheet

PMD

Only EPA's general rule applies: nothing on pets unless the label says so.

Source and detail: EPA, US EPA

EPA's page on using insect repellents says not to use any product on pets or other animals unless the label clearly states it is for animals; the instruction is general, and it is the only agency statement on pets that reaches PMD. That page adds that most insect repellents do not work against lice or fleas.

Do not use any product on pets or other animals unless the label clearly states it is for animals. Most insect repellents do not work against lice or fleas.
US EPA, Using Insect Repellents Safely and Effectively

Do not use any product on pets or other animals unless the label clearly states it is for animals.
EPA, Using Insect Repellents Safely and Effectively

Which studies are on the record?

DEET

One trial found 20% DEET and 20% picaridin performed equally, with 97.4% protection over five hours.

Source and detail: Carroll JF, Van Roey K

Van Roey 2014 (PLoS Neglected Tropical Diseases) reported an overall five-hour protection rate of 97.4 percent, with picaridin 20 percent performing equally well as DEET 20 percent. Carroll 2010 (Journal of Medical Entomology) found formulations of deet, picaridin and IR3535 at 20 percent or more active ingredient highly effective against lone star ticks over 12 hours, with fewer than 10 percent of ticks crossing the treatment bands.

Based on a total of 4996 mosquitoes collected on negative control persons, the overall five hour protection rate was 97.4% [95%CI: 97.1-97.8%], not decreasing over time. Picaridin 20% performed equally well as DEET 20% and better than picaridin 10%.
Van Roey K, et al. Field evaluation of picaridin repellents reveals differences in repellent sensitivity between Southeast Asian vectors of malaria and arboviruses. PLoS Negl Trop Dis. 2014 Dec 18;8(12):e3326. PMID 25522134

Formulations containing > or = 20% active ingredient were highly effective, with <10% of the ticks crossing through the treatment bands for any challenge during the 12 h. At least 40% of ticks exposed to any formulation for any challenge fell or crawled off the volunteers.
Carroll JF, Benante JP, Kramer M, Lohmeyer KH, Lawrence K. Formulations of deet, picaridin, and IR3535 applied to skin repel nymphs of the lone star tick (Acari: Ixodidae) for 12 hours. J Med Entomol. 2010 Jul;47(4):699-704. PMID 20695288

There was no difference in effectiveness between the 20% spray and 20% lotion formulations of picaridin. The 10% IR3535 lotion was significantly less effective than the formulations with higher concentrations of repellent. In the formulations tested, deet, picaridin, and IR3535 provided lasting protection against A. americanum.
Carroll JF, et al. J Med Entomol. 2010 Jul;47(4):699-704. PMID 20695288

PMD

One 2006 paper concluded CDC's endorsement was warranted and probably underestimated PMD's value as a DEET alternative.

Source and detail: Carroll SP

Carroll and Loye, Journal of the American Mosquito Control Association, 2006, concluded that the CDC endorsement was not only warranted but probably underestimated the value of PMD as a DEET alternative for public health applications. The same paper describes PMD as a spent product of distilling leaves of the Australian lemon-scented gum.

We conclude that not only is the CDC endorsement warranted but also that it probably underestimates the value of PMD as a deet alternative for public health applications.
Carroll SP, Loye J. PMD, a registered botanical mosquito repellent with deet-like efficacy. J Am Mosq Control Assoc. 2006;22(3):507-14. PMID 17067054

para-Menthane-3,8-diol(PMD) is a monoterpene spent product of the distillation of leaves of the Australian lemon-scented gum tree (updated nomenclature Corymbia citriodora ssp. citriodora).
Carroll SP, Loye J. PMD, a registered botanical mosquito repellent with deet-like efficacy. J Am Mosq Control Assoc. 2006;22(3):507-14. PMID 17067054

Sources on this page.

21 sources. Every quote was fetched on or before 2026-09-22 and is stored with the page. Last reviewed 2026-09-22. All ten actives.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22. https://www.epa.gov/insect-repellents/deet
CDC Yellow Book, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture 2026-09-19). https://www.cdc.gov/yellow-book/hcp/environmental-hazards-risks/mosquitoes-ticks-and-other-arthropods.html
EPA, Find the Repellent that is Right for You, search results for DEET, cfpub.epa.gov/oppref/insect_s. https://cfpub.epa.gov/oppref/insect_s/search_results.cfm
EPA, Find the Repellent that is Right for You. https://www.epa.gov/insect-repellents/find-repellent-right-you
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