Diseases spread by mosquitoes and ticks, or both, are serious enough that it’s necessary to take precautions if you live in an area where they are prevalent. Over the past few decades, the number of mosquito- and tick-borne diseases has increased. Two disturbing cases in point are the mosquito-borne Zika virus and the tick-borne Powassan virus. Additionally, there has been a yearly increase in the incidence of well-known infections like Lyme.
Before purchasing an insect repellent, you might not give much thought to reading the label. That’s a bad idea because the potency and safety depend on the exact active component and dosage.
Products that fared best in our tests were those that included either deet, oil of lemon eucalyptus, or picaridin as an active component. When used properly, each is risk-free. Learn about the essentials of active ingredients here.
The more deet (N,N-diethyl-meta-toluamide) a product has, the better, so many people think. However, our research shows that solutions containing 15–30% deet are effective in repelling mosquitoes and ticks for an extended period of time without the need for a larger concentration. And there’s evidence to suggest that using too much of the product can bring on the rare side effects like rashes and even seizures that have been linked to deet.
The active ingredient here is a synthetic replica of a substance found in black pepper. Two picaridin sprays (20%) and one picaridin spray (10%) are suggested.
Lemon Eucalyptus Oil
This compound is a refined form of a substance taken from the gum eucalyptus tree. In addition to natural synthesis, synthetic production is possible. Our testing found that four of the insect repellents containing 30% OLE performed well.
IR3535 and 2-Undecanone
The Centers for Disease Control and Prevention (CDC) recommends using both of these active components in insect repellents; nevertheless, our testing shows that solutions having only these two compounds are not as effective as those comprising deet, picaridin, and OLE.
Things to Consider from the Latest Buzz
Watch Out for “Natural” Repellents:
Some “natural” insect repellent manufacturers say that their products may effectively deter mosquitoes, even those that may be carrying the Zika virus, since they contain essential plant oils including cedar, citronella, clove, lemongrass, peppermint, and rosemary. However, our experiments reveal that these active substances aren’t particularly effective, typically failing within 30 minutes.
Do not make a purchase based only on the labeled ingredients or claimed concentration:
Picaridin is included in both some of our highest- and lowest-rated items. Some of the distinction is likely attributable to concentration and shape: Products that scored highly had 20 percent picaridin in a spray format, whereas those that scored poorly either contained less picaridin or were in a less effective delivery system (such as a lotion or wipe). According to our research, treatments containing deet at concentrations between 15 and 30 percent are the most effective at repelling mosquitoes.
Insect repellent and sunblock products should never be used together:
Because sunscreen needs to be reapplied every two hours, we don’t recommend products that combine sun protection with insect repellent.