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 things you can do:
- Avoid cultivating insect habitats. Drain standing water where mosquitoes breed.
- Wear long-sleeved shirts and long pants. Wear them 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. Repellents with DEET have been shown to be more effective than other products in preventing mosquito bites in particular. Repellents with DEET are available as sprays and lotions.
Repellents With DEET: Are They Safe?
DEET is safe when used according to directions. DEET should not be used on children younger than two months of age. The Environmental Protection Agency (EPA) does not suggest using any special precautions for using registered repellants on pregnant or on women who are breastfeeding. Contact your doctor if you have any concerns about using products that contain DEET. See this website from the Centers for Disease Control and Prevention (CDC) for more information about the safety of insect repellents: http://www.cdc.gov/ncidod/dvbid/westnile/qa/insect%5Frepellent.htm.
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 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 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:
- Avoid using products that combine sunscreen with DEET. It may lead to overuse and toxicity, since repellent does not need to be reapplied as often as sunscreen.
- Always follow the instructions on the product label.
- Do not apply repellent under clothing.
- Do not apply repellent to cuts, wounds, or irritated skin.
- Wash treated skin with soap and water after returning indoors.
- Wash DEET-treated clothing after returning indoors.
- Do not spray DEET products in enclosed areas.
- Do not spray DEET products directly on your face. Spray your hands and then rub them carefully over the face, avoiding the eyes and mouth.
- Choose a product with less than 30% DEET.
- If you start to get mosquito bites, reapply the repellent according to the instructions on the product label.
When using products with DEET on children:
- Do not use DEET products on babies under the age of two months. Consult the pediatrician if your baby needs protection from insects.
- When using repellent on a child, apply it to your own hands and then rub them on your child. Supervise older children.
- Do not apply repellent to children's hands. Children may put their hands in their mouths or use them to touch their eyes.
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 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. Its effectiveness is comparable to DEET, but it is odorless and does not irritate skin. It is also effective against other insects like fleas or ticks.
What about products that aren’t applied to the skin? Research says that garlic and thiamine (vitamin B1) are not effective.
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 are worried about using DEET, talk to your healthcare provider for advice. And enjoy a bug-free summer.
- Reviewer: Brian Randall, MD
- Review Date: 05/2011 -
- Update Date: 06/17/2013 -