The best way to protect yourself from mosquito-borne diseases is to avoid mosquito bites when going outdoors. EPA-registered insect repellents such as those containing DEET, Picaridin, Oil of Lemon Eucalyptus, IR3535 or Permethrin will provide effective protection against mosquito bites when used properly.

Culex tarsalis

How Repellents Work

Female mosquitoes in search of a blood meal use their antennae to respond to chemical cues produced by humans and other animal hosts. These chemicals include carbon dioxide which is exhaled during breathing and lactic acid which is produced and left on the skin by sweat. Warmth and moisture emanating from the skin create convection currents that enable mosquitoes to follow a chemical pathway right to the host.

Effective mosquito repellents contain chemicals that interfere with the mosquito's ability to detect the host's natural chemicals. When applied to the skin, molecules of repellent enter the convection currents and mask the presence of lactic acid and other chemicals. Upon approach, the mosquito turns away from the skin instead of landing on it.

Active Ingredients

CDC evaluation of information contained in peer-reviewed scientific literature and data available from EPA has identified several EPA registered products that provide repellent activity sufficient to help people avoid the bites of disease-carrying mosquitoes. Products containing these active ingredients typically provide reasonably long-lasting protection:

  • DEET (Chemical Name: N,N-diethyl-m-toluamide or N,N-diethly-3-methyl-benzamide)
  • Picaridin (KBR 3023, Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester )
  • Oil of Lemon Eucalyptus* or PMD (Chemical Name: para-Menthane-3,8-diol) the synthesized version of oil of lemon eucalyptus
  • IR3535 (Chemical Name: 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester)

Certain products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear, and are registered with EPA for this use. Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other arthropods and retains this effect after repeated laundering. The permethrin insecticide should be reapplied following the label instructions.  Some commercial products are available pretreated with permethrin.

Mosquito Repellent Guidelines

Read and follow all instructions on the label before applying for the best results.

Apply insect repellents only to exposed skin and/or clothing (as directed on the product label). Do not use repellents under clothing.

Do not apply to cuts, irritated or sunburned skin.

Do not spray in enclosed areas. Avoid breathing the spray and do not spray near food.

Do not spray products directly on your face. Spray your hands and then rub your face, avoiding eyes and mouth.

Use just enough repellent to cover exposed skin and/or clothing. Heavy application and saturation are generally unnecessary for effectiveness.

After returning indoors, wash treated skin with soap and water. This is especially important if you are applying repellents in a day or over several days.

For more information about repellents, please visit the Center for Disease Control website at