Insect Repellent Sunscreen

It’s that time of year again. The sun is out, the temperatures are rising, and a new crop of mosquitos is coming to town. If you live in an area where one of these two pests is a problem, then you’re likely looking for ways to keep the mosquitos at bay. While you might have tried bug spray or citronella before, have you ever considered insect repellent sunscreen as part of your strategy? While it sounds like an oxymoron, it actually works and has been in use for years.

Insect Repellent Sunscreen

The debate on the application of sunscreen with DEET is an old one. Using DEET insect repellent with sunscreen decreases the effectiveness of the sunscreen by about 30-40%. So if using both at the same time, be prepared to re-apply sunscreen more often than if using sunscreen alone.

There are several commercial products that combine DEET and sunscreen into one cream or lotion. These are generally not as good as using two separate products.

Should You Apply Deet or Sunscreen First?

For several years, the Travel Medicine community has preached application of sunscreen first and then DEET applied over the sunscreen.

This information comes from the CDC Yellow Book. Put the sunscreen on first, allow a period of about 5-10 minutes to allow the sunscreen to dry, prior to applying DEET insect repellent. The UK’s NHS Fit for Travel gives the same advice as the CDC.

Advice from the International Association for Medical Assistance to Travellers also says to apply the sunscreen first and DEET second.

Studies on DEET and Sunscreen

It’s important to note that evidence to support the application of sunscreen before or after DEET based insect repellent is limited.

Some medical experts have suggested that whichever way the two products are applied has little effect on the decreased efficacy of sunscreen. This decreased protective effect of sunscreen when used with DEET is unavoidable due to the product’s chemical interactions.

It’s been hypothesized that the sunscreen applied over the DEET may interfere with the evaporation of the DEET, thus lowering its ability to repel mosquitoes. However, there is no peer reviewed literature to back this statement.

The other belief is that DEET might be less absorbed by the skin if sunscreen were applied first, protecting the skin. Obviously, the goal is to reduce the skin’s absorption of DEET as much as possible. This is also another theory without decent evidence.

Basically, there is no clear, scientifically robust evidence that support these theories; therefore a substantial study needs to be done examining this issue further.

In the meantime, it’s advised you reapply both often to avoid being sunburnt and keep the bitey beasts at bay. This is particularly important if you go swimming, shower or sweat a lot.

Although protecting you and your loved ones from both sun damage and insect bites with one product sounds convenient (anyone with squirmy small children wishes for that), it is better to use two different products.

Sunscreens and insect repellents are both effective and safe when used separately, but if combined, problems can arise. Certain sunscreen formulations decrease in their ability to screen out ultraviolet (UV) radiation when used with DEET (N,N-Diethyl-m-toluamide), the most effective and common bug repellent. In some studies, the combination led to a more than 30 percent reduction in SPF. What’s more, sunscreens enhance absorption of DEET into the skin, potentially increasing toxicity — especially in children.

The problem is compounded by the application directions. You should apply sunscreens generously and frequently: That means one ounce of sunscreen to the entire body at least every two hours — and more often if you’re swimming or sweating. You should only apply insect repellents, though, every two to six hours, depending on the concentration, and you should avoid applying it to the face. It is difficult to reconcile the opposing requirements of combination formulations.

In summary, I advise you to use two separate products. Apply sunscreen first, then an insect repellent, following the manufacturer’s instructions for each.

Insect Repellent Sunscreen

It is advisable to stay away from products that have combination of sunscreen and insect repellent as they could be very harmful to one’s skin. Instead apply sunscreen and insect repellent individually.

List Of Insect Repellent Sunscreen