Fight the Bite: Effective Repellents to Reduce Tick and Mosquito Bites

[PROF. ERIKA MACHTINGER] The use of repellents is a great way to prevent vector bites, but there are so many repellents that you can buy.

How do you know which ones are effective?

Let's talk about four common active ingredients that you can find in tick and mosquito repellents.

The active ingredient is the chemical compound that makes the repellent work.

This information is listed on the repellent's label.

The most common active ingredients are DEET, Picaridin or Icaridin, Oil of Lemon Eucalyptus, or PMD, and IR3535.

Deet is probably the repellent you have heard about the most, and you can find readily in most stores.

Looking at this label on the left, you can see that the active ingredient is 25% DEET, and on the label on the right is 100% DEET.

Intuitively, you may think that the product on the right will give you better protection, but is that really the case?

The answer is no, not really.

The myth is that the higher the percent of the active ingredient, the better the protection.

But really, the greater the percent, the greater the duration of the product.

So in this case, 25% DEET and 100% DEET have the same effectiveness, but 100% DEET will last longer.

That being said, there are some plateaus in the effectiveness of repellents against ticks and mosquitoes, and a greater percentage isn't going to give you better protection.

Generally, 25 to 40% DEET is considered sufficient as a repellent.

But what about DEET safety?

Well, DEET is the most widely used and studied repellent.

It is the World Health Organization and Centers for Disease Control and Prevention referenced standard, meaning all other repellents are compared to how well DEET works.

One disadvantage to DEET is that it does have a distinct oily texture and odor, and DEET can interact poorly with some plastics leaving them misshapen, and that can be off-putting to some.

Deet is very low risk when used correctly, including for children and pregnant women.

The next active ingredient is Picaridin, or sometimes seen as Icaridin.

Like DEET, this is another repellent recommended by the CDC.

Picaridin-based products have an effectiveness that is similar to DEET, and has a different odor and is less greasy.

Picaridin can be more expensive and challenging to find, and while the EPA has deemed it low-risk, there is more limited data than with DEET.

Repellents with Oil of Lemon Eucalyptus as an active ingredient use a synthetic version of the active compound that was originally derived from a plant, which may seem more natural to some.

It uses a compound called PMD found in the leaves of specific plants that makes it harder for insects to pick up on your skin odor.

Many find the odor of Oil of Lemon Eucalyptus repellent to be more pleasant because the synthetic version is based off the lemon-scented gum tree.

And although data is more limited than DEET, this active ingredient is considered low-risk for most people over the age of three.

It is important to understand that the non-synthetic, or pure oil of lemon eucalyptus, has not been studied or registered.

Most commercially available insect repellents contain a processed lemon eucalyptus oil that intensifies its concentration of PMD, and in turn increases its power and duration as a repellent.

Ir3535 is another active ingredient.

Products with this active ingredient are not as easy to find as some of the others, but it is preferred by some because it is not as greasy and has no odor.

There's also a long history of use in Europe before this active ingredient made it to the United States.

There's also a new active ingredient called nootkatone.

This compound is derived from the Alaskan yellow cedar tree and has a pleasant grapefruit smell, and was approved by the EPA for use as a repellent in 2020.

A repellent registered with the EPA means the product has been rigorously tested for effectiveness in preventing vector bites and for safety and consistency.

This is not the case for homemade blends and essential oils.

Plant growing conditions like sunlight, soil, and age can alter the compounds that are used in repellents.

Essential oil blends may then be used from plants that do not have the right or enough of the right active ingredient to be effective, allowing ticks or mosquitoes to bite still.

These blends can also be dangerous if misused as both people and domesticated animals can have severe dermal and other reactions to some oils.

Unfortunately, these products are used by people wanting more natural products thinking they are safer.

But in fact, essential oils and blends have the least amount of safety data and are not recommended for use.

Remember that EPA-registered repellents are recommended because of the rigorous testing these products undergo to ensure they are low-risk and effective.

Always read the label of whichever repellent you choose to learn the best application methods and understand all safety data.

Consistently using these repellents when you are in mosquito and tick habitat can lower your risk of bites and help keep you and your family safer from vector-borne diseases.