The chemical compound DEET is effective at repelling mosquitoes when applied to the skin at a concentration of 20 to 30 percent.

The chemical compound N,N-diethyl-meta-toluamide, commonly known as DEET, is a widely recognized and effective active ingredient in insect repellents. Health organizations and environmental guides consistently categorize products with concentrations ranging from 20 to 30 percent as providing highly effective protection against mosquito bites for several hours. Research indicates that increasing the concentration of DEET does not necessarily intensify the repellent effect; instead, it primarily extends the duration of protection provided by a single application.sgvmosquito.orgsgvmosquito.orgYour Mosquito Repellent 101 Choosing the Right Active IngredientsThe concentration of DEET does not necessarily change how well it repels insects (its efficacy), but rather how long it remains effectivemikemoats.commikemoats.comWhat Percent of Deet Is EffectiveRelationship Between Concentration and Duration: Higher concentrations of DEET do not necessarily increase the intensity of the repellent effect, but they do increase the duration of protection General Use: Experts often advise using the...