DEET versus natural mosquito repellents

Skin Care article posted on Aug 21, 2008 by Joséphine Beck, Digestive Care Advisor & Optiderma Founding member

I was reading the local newspaper this morning and my attention was caught by health information on the West Nile Virus. Health Link Canada claims that "your best protection is insect repellent with DEET. Used as directed, DEET has an excellent safety record. Products with lemon eucalyptus oil are effective for shorter periods of time".

I immediately wondered if using a natural mosquito repellent increases the risk of being infected with West Nile virus. Is it much safer to use a DEET mosquito repellent?

Is DEET the most effective insect repellent?
But is it safe to use on a regular basis?
Are natural mosquito repellents better alternatives and do they work?
What about natural lotions for babies and pregnant women?
Related useful links

Is DEET the most effective insect repellent?

DEET (N, N-diethyl-meta-toluamide) works by blocking the insect’s senses so that it is not attracted to human sweat and breath. Many studies show that it is the most effective insect repellent.

Its effectiveness also depends on its concentration : ‘100% DEET was found to offer up to 12 hours of protection while several lower concentration DEET formulations (20%-34%) offered 3-6 hours of protection’ .

Conclusion: yes, DEET is very effective and provides the best protection against ticks and mosquitoes.

But is it safe to use on a regular basis?

According to studies, DEET is very safe to use. Products containing less than 30% of DEET are supposed to be safe for children from 2 months old. There is no indication that DEET poses a risk for pregnant or nursing mothers.

Yet, I still wonder how a solvent that can dissolve plastic and peels paint is not toxic for our body. DEET is actually a moderate chemical pesticide. Originally it was used as a pesticide for farm fields and was developed by the United States army during World War II. Do we really want such a chemical to penetrate our bloodstream through our skin?

Manufacturers advise that DEET should not be used under clothing or on damaged skin, because it can irritate the skin. Cases of serious reactions to products containing DEET have actually been reported when using for multiple days without washing the skin in between use. Other studies show that DEET is slightly toxic for the environment, especially in water sources.

Conclusion: DEET may be an effective insect repellent, but its safety is still questionable.

Are natural mosquito repellents better alternatives and do they work?

It is shown that lemon eucalyptus (eucalyptus citriodora) repellents are a highly effective and non toxic alternative to DEET.

Although oil of eucalyptus products should not be used on children under 3 years of age, it appears to be a safer choice when applied on the skin and the most effective natural way to repel insects.

Other essential oils such as Geranium, Soybean, and Citronella oil are also proved to be quite effective. Lemongrass, Peppermint, Thyme, Rosemary, Neem, Cinnamon, Castor, Cedar, and Clove Oil also have good results but are still being researched.

In any case, be sure you are not allergic to any of these essential oils before using it on your whole body.

Furthermore, most oils should not be applied undiluted to skin (e.g. Thyme and clove oil). You could add a few drops to your shampoo, conditioner, sunscreen or body lotion.

Conclusion: # 1 natural mosquito repellent = Lemon Eucalyptus oil

What about natural lotions for babies and pregnant women?

Wearing protective clothing is certainly the best alternative especially for babies and pregnant women, but that's not always an option in the heat of summer.

Apparently, eating garlic or foods rich in vitamin B1 do not really provide protection against mosquitoes.

So try to avoid what actually attracts mosquitoes:

Dark clothing, floral or fruity fragrances, moisture
Cooler temperatures of the extremities
Lactic acid produced by the body after exercising or after eating certain foods such as salty foods or high-potassium foods
Carbon dioxide from a source of fire or even when you are hot or have been exercising

Conclusion: If you are in a place with a high rate of insect diseases (e.g. West Nile virus or Lyme disease), or you experience severe allergic reactions to bites and stings, it might be worth using DEET products. Otherwise, on a regular basis, there are lots of effective DEET-free products and safer alternatives.

Remember to reapply natural mosquito repellents more often because they are not quite as long lasting, and try to avoid as much as possible what appeals to mosquitos.