Choose the Best Insect Repellent
In warm weather, mosquitoes, ticks, flies, and other insects become annoying pests—and potential carriers of disease. So what’s your best protection? There are three things you can do:
- Avoid cultivating insect habitats by draining standing water where mosquitoes breed.
- Wear long-sleeved shirts and long pants, especially at dawn and dusk when mosquitoes are most active.
- Wear insect repellent. This is the most effective protection from insect bites.
Insect Repellent Basics
There are two kinds of insect repellents: man-made chemicals and plant-based essential oils. The best-known chemical repellent is DEET—the common name for N,N-diethyl-m-toluamide. DEET is the main ingredient in many insect repellents today. Many plant-based repellents have been studied, but research holds that DEET gives the most protection for the longest period of time. Repellents with DEET are available as sprays and lotions.
Repellents With DEET: Are They Safe?
Repellents with DEET have been used for almost 50 years. Research over this time has proved that DEET is very safe when used according to the directions. DEET can even be used safely on children and women who are pregnant and breastfeeding.
In rare cases, repellents with DEET may cause skin reactions. However, most of these cases have happened when the product was not used according to the directions, such as accidental swallowing, applying over broken skin, and using over many days without washing in between.
If you think you have a reaction to a DEET product, wash the treated skin and contact a Poison Control Center near you: 1-800-222-1222 .
Using DEET Products Safely
Check the product label for information about how much DEET the repellent contains. The more DEET a repellent contains, the longer it can protect you from insect bites. For example, a recent study showed that a product with 23.8% DEET gave about five hours of protection from mosquito bites. A product with 6.65% DEET gave almost two hours of protection.
When using products with DEET:
- Always follow the instructions on the product label.
- Don't apply repellent under clothing.
- Don’t apply repellent to cuts, wounds, or irritated skin.
- Wash treated skin with soap and water after returning indoors.
- Don’t spray DEET products in enclosed areas.
- Don’t spray DEET products directly on your face. Spray your hands and then rub them carefully over the face, avoiding the eyes and mouth.
- The American Academy of Pediatrics suggests using repellent with lower concentrations of DEET (30% or lower) on children over two months old; DEET is not recommended for use in babies under the age of two months. Consult your physician if your baby needs protection from insects.
- Adults are probably best served by using a 10%-30% extended release DEET product rather than a regular release product with a higher DEET concentration; the lower concentration extended release products decrease the potential of DEET toxicity or skin reactions.
- When using repellent on a child, apply it to your own hands and then rub them on your child. Avoid the child’s eyes and mouth and use it carefully around his or her ears.
- Do not apply repellent to children's hands. (Children may put their hands in their mouths.)
- Do not allow young children to apply insect repellent to themselves; have an adult do it for them.
Promising Alternatives to DEET
Most plant-based insect repellents use essential oils from one or more of these plants: citronella, cedar, eucalyptus, peppermint, lemongrass, geranium, and soybean. Of the products tested in a recent study, a soybean oil-based repellent gave protection from mosquito bites for about 1.5 hours. This is similar to a product with a low concentration of DEET (4.75%).
Use a soybean oil-based product instead of DEET if you:
- Have had allergic skin reactions to products with DEET in the past
- Have irritated, sunburned, bruised, or broken skin
- Have a skin condition such as skin cancer, dermatitis, acne, eczema, or psoriasis
When using soybean oil-based repellent, reapply the product if you are outdoors for longer than 90 minutes, or if you start being bitten by mosquitoes.
Picaridin is a product developed by Bayer. It has been widely used in Europe and Australia. It effectiveness is comparable to DEET, but it is odorless and does not irritate skin. It has been recommended by WHO as the best protection against malaria. It is also effective against other insects like fleas or ticks.
All other plant-based repellents that have been tested so far—no matter what their ingredients—have been shown to keep insects away for only a short period of time: from three to 20 minutes.
What about products that aren’t applied to the skin? Research says that swallowing garlic or ]]>thiamine]]> (vitamin B1) is not as effective as an insect repellent. Also, wristbands treated with either DEET or citronella provide no protection from bites.
The Best Repellent for You
Choose a repellent that you will use every time and that will give you enough protection for the amount of time you will be outdoors. If you’re worried about using DEET, talk to your healthcare provider for advice. And enjoy a bug-free summer.
Centers for Disease Control and Prevention: Lyme Disease Information
Centers for Disease Control and Prevention: West Nile Virus Fact Sheet
Environmental Protection Agency Insect Repellent Information
National Pesticide Information Center
Canadian Public Health
The College of Canadian Family Physicians
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Last reviewed May 2009 by ]]> Rosalyn Carson-DeWitt, MD ]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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