In spite of what other urban myth and legend sites may tell you (like Snopes.com who still doesn’t seem to have heard about Google), Listerine does indeed have a key ingredient proven to repel mosquitoes. Eucalyptol, a derivative of eucalyptus which does repel mosquitoes. And the Centers for Disease Control lists it as one of several mosquito repellents that was registered as an insecticide in 1948! The only issue is you might need to use a lot more Listerine than mosquito repellent due to the lower concentrations or repellent substances, but at least you will smell fresh and clean. And if you’re stuck in the woods and you only have that 2 liter bottle of Listerine, it’s definitely better than nothing.
Here’s the Listerine mosquito killer e-mail:
Subject: mosquito killer
The best way of getting rid of mosquitoes is Listerine, the original medicinal type. The Dollar Store-type works, too. I was at a deck party awhile back, and the bugs were having a ball biting everyone. A man at the party sprayed the lawn and deck floor with Listerine, and the little demons disappeared. The next year I filled a 4-ounce spray bottle and used it around my seat whenever I saw mosquitoes. And voila! That worked as well. It worked at a picnic where we sprayed the area around the food table, the children’s swing area, and the standing water nearby. During the summer, I don’t leave home without it…..Pass it on.
Pass it on. I don’t know about you, but mosquitoes eat me alive if I don’t use something to keep them away! And with all the rain we have had in Owensboro, KY we will be loaded with mosquitoes real soon. Our temperature today is in the 70’s so they are coming, especially in my neighborhood, Woodcrest Subdivision, where there is a lake!
CDC information confirms the active ingredient in Listerine can help repel mosquitoes:
CDC evaluation of information contained in peer-reviewed scientific literature and data available from EPA has identified several EPA registered products that provide repellent activity sufficient to help people avoid the bites of disease carrying mosquitoes. Products containing these active ingredients typically provide reasonably long-lasting protection:
Oil of Lemon Eucalyptus is found naturally in eucalyptus leaves and twigs. It was first registered in 1948 as an insecticide and miticide (kills insects and mites) and today is found in both lotion and spray insect repellents. As with most plant oils, no adverse effects to humans are expected. Products contain a range of 30 to 40 percent of the active ingredient. Technical fact sheet on Oil of Lemon Eucalyptus (PDF) (4 pp, 44K, About PDF.)
In fact one product called Repel Lemon Eucalyptus has been proven to be effective against mosquitoes, deer ticks and no-see-ums for up to six hours. Derived from Oil of Lemon Eucalyptus, a renewable resource, this non-greasy lotion and pump have a pleasant scent and are perfect for the whole family. Oil of lemon eucalyptus, in addition to DEET and Picaridin, has been recommended by the Centers for Disease Control and Prevention (CDC) for effective protection against mosquitoes that may carry the West Nile virus.
So do not be brainwashed. Chemical sprays are not the only substances that can repel mosquitoes. Natural substances can do so too, here’s a list of other mosquito repellants and studies on their effectiveness, via About.com:
Fennel – A small study by researchers at Seoul National University in Korea found that a spray mosquito repellent containing 5% fennel oil was 84% effective after 90 minutes and a repellent cream with 8% fennel oil was 70% effective after 90 minutes.
Thyme – In one study, carvacrol and alpha-terpinene, two compounds derived from the essential oil of thyme, were found to have significantly greater repellency than a commercial DEET repellent. The researchers suggest that a spray made with 2% alpha terpinene is a promising natural mosquito repellent. However, don’t try to make a thyme oil repellent at home- it is too irritating and strong-smelling to be used at effective concentrations above 25%.
Clove oil – Two studies have found that undiluted topical clove oil is active against mosquitoes. However, like thyme oil, clove oil should not be applied undiluted to skin as a homemade repellent.
Celery extract – A Thai study compared 15 mosquito repellents with a topical extract from celery. The researchers found that the extract did not irritate the skin or cause a burning sensation. It was found to be active against a wide range of mosquito species comparable to a 25% DEET formula.
Neem oil – An extract from the tropical neem tree, neem oil has insecticidal compounds called azadirachtins.
Vitamin B1 – Vitamin B1 is often taken to help repel mosquitos but one study suggests this remedy may be useless. Researchers at the University of Wisconsin study tested B1 with a larger sample of human subjects and found no effect of vitamin B.
Garlic – Another popular theory is that ingesting garlic can provide protection against mosquitoes. A University of Connecticut study examined this claim with a randomized, double-blinded, placebo-controlled crossover study. The data didn’t provide evidence of significant mosquito repellence. However, subjects only consumed garlic once, and the researchers say that more prolonged ingestion may be needed.