MOSQUITO REPELLANTS….What works? What doesn’t?

Although we have not had a lot of rain so far this year, Dengue fever is already starting to appear in pockets around the Island. Other diseases such as Japanese Encephalitis, Chikungunya and Malaria (there is not so much Malaria in Bali), are transmitted by mosquitos.

Do you seem to get eaten alive when others are left alone? You’re probably not just imagining it. Everyone’s body chemistry is a little different, and some people are more likely to attract unwanted insect advances than others are. Mosquitoes can sense your presence from far away. When you breathe out, you emit a plume of carbon dioxide that carries on the breeze, and CO2 also seeps from your skin.

Mosquitoes are attracted to carbon dioxide as well as the warmth and humidity you’re giving off. Hence those with a higher body temperature (e.g. pregnant women) are easily targeted.

One way to avoid being bitten is to use a repellant. From zappers to catchers to candles and sprays, mosquito repellents come in many forms. But which ones really work?

Here are some tips on how to stay off a mosquito’s menu.




DEET: Potent, But Safe

One of the most effective mosquito repellents is one of the oldest around. DEET was first developed for use by the U.S. Army in 1946, and it became available to the public in 1957. Many other products have hit the market since then, but few compare to DEET. In fact, it’s one of two ingredients in mosquito repellent that the CDC recommends for preventing mosquito-borne diseases. The other is picaridin, and the CDC believes these two ingredients are more effective than other mosquito repellents.

DEET has an excellent safety record, despite some people’s concerns. N,N-diethyl-3-methylbenzamide doesn’t sound like something you’d want to spray on your skin, and perhaps its acronym reminds people of the dangerous and now banned insecticide DDT. They’re nothing alike, however.




Lemon eucalyptus oil

The most effective natural mosquito repellent so far. A 2002 study in the New England Journal of Medicine compared different synthetic chemical and herbal repellents. A Lemon Eucalyptus Repellent provided 120 minutes of mosquito protection, more than a repellent with a low concentration of the chemical DEET (4.75% DEET provided 88.4 minutes of protection and 23.8% DEET, provided 301.5 minutes of protection).


Geranium oil and soybean oil

The New England Journal of Medicine study found that repellants containing these oils provided 94.6 minutes of protection against mosquitoes. This is slightly more effective than 4.75% DEET.



A well-known natural mosquito repellent. The oils from the plant are used to make lotions, sprays, and candles. A University of Guelph study assessed the effectiveness of 3% citronella candles and 5% citronella incense in protecting subjects from bites. They found that subjects who were positioned near the citronella candles had 42.3% less bites and those near the citronella incense had 24.2% fewer bites. Based on these results, citronella candles shouldn’t be used as a stand-alone repellent, all though they may help in combination with topical repellents.

The least effective products were wristbands treated with DEET or citronella, which offered almost no protection. According to the researchers, this wasn’t a surprise. It’s known that mosquito repellent only works on the surface to which it’s applied directly. Mosquitoes are happy to bite skin only four centimeters away from the repellent band.


THE RUBBISH – It just don’t work

Garlic: Is there an old wives’ tale that doesn’t feature garlic? According to lore, the pungent-smelling plant can do everything from cure the common cold to help determine a baby’s sex to ward off witches. But though some believe garlic has powerful bug-repellent properties, mosquito control experts say it just does not work.

Vitamin B: Can vitamin B tablets make you a less tasty treat to the biting menaces? Probably not. Though some people swear by it, when researchers at the University of Wisconsin asked volunteers to take placebos or capsules with vitamin B, they did not find any evidence that the substance could help reduce mosquito attraction.

Bananas, Listerine, Dryer Sheets, Lemon Dish washing soap. Skin-so Soft and alcolhol have all been proven not to work



Most people have seen advertisements for fancy ultrasonic mosquito repelling devices intended to drive off mosquitoes by subjecting them to repelling ultrasonic vibrations. These gadgets sound great, except for one thing-they don’t work. Both scientific and anecdotal evidence indicates that as mosquito repellents, ultrasonic really don’t seem to have any effect. Don’t be fooled by expensive, high-tech gadgets!



  • Mosquito nets, and screens can be used in problem areas. Babies and young children should always be protected by cot, or pram covers.
  • Avoid the use of perfumes or colognes
  • Wear long sleeved, loose light-colored clothing while walking in garden areas.
  • Personal repellants may be used; however, they should be used with caution in the very young, or the elderly.
  • Make sure that your garden and surrounding area are free of water catchments, or that water containers are covered.
  • Keep larvae eating fish, such as guppies, in ponds.
  • Use chemical larvicides in ponds, drains or other water catchments.
  • Remove garbage, or unnecessary pots, bottles, cans etc from the garden area.
  • Mozzie repellant plug-ins, or vapor mats can be used indoors in the early mornings and late afternoons during the wet season.


Kim Patra is a qualified health consultant who has been living and working in Bali for over 30 years. She now runs her own private practice in Sanur.

Kim is happy to discuss any health concerns that you have and may be contacted via email at, or

Copyright © 2020 Kim Patra

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