There are many different kinds of insect repellents and bug sprays on the market: sprays and lotions, chemical and natural, huge percentages of DEET and lower percentages, etc.

What type of mosquito repellent is most effective (for travelers to tropical destinations)? What types should be avoided or are just a marketing ploy?

I'm not asking for specific product recommendations, but general advice about types of insect repellent (e.g. 100% DEET vs. 30% vs. citronella oil, etc.).

Edit: Starting a bounty to try to get a few more details. Thanks for the answers so far! But it would be great to see some real details (with references) about the effectiveness of different kinds of repellents, different concentrations of DEET, sprays vs. lotions, etc.

  • I am wondering if different types of mosquitoes react in a different way, e.g. I found DEET not very effective in Eastern Europe.
    – Grzenio
    Sep 29, 2011 at 6:59
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    I also found DEET to be ineffective in Kakadu National Park Australia where the large and abundant mosquitoes are not daunted by temperatures of 50 degrees Celsius and direct sunlight. They seem to like a good sip of DEET as an aperitif with their meal of mammal blood. Oct 1, 2011 at 12:10

7 Answers 7


The US Center for Disease Control (CDC) recommends DEET, Picaridin, IR3535, and lemon eucalyptus oil (active ingredient being p-menthane 3,8-diol). There was also apparently a claim that catnip is 10x more effective than DEET at repelling mosquitoes, but I've never encountered any catnip-based repellents. Outdoor retailer REI has a pretty thorough comparison of the pros and cons of common insect repellents, but they don't really cite research.

DEET seems to be agreed upon as the most effective insect repellent, but there are a lot of arguments about its safety.

The ATSDR (a sub-agency of the CDC) has a page on their site about the effect of DEET in humans. They cite several other studies and summarize reports of (many upsetting) side effects of DEET use, including this one:

A study was done involving 143 National Park Service employees at Everglades National Park to determine the effects of DEET on varying use groups. Exposure groups were classified as low (non-users), medium (0.01-0.52 g/day) and high (0.71-69.38g/day) use of DEET. It was found that 36 of the workers (25%) reported health effects that they attributed to DEET. These effects included rashes, skin or mucous membrane irritation, transient numb or burning lips, dizziness, disorientation, and difficulty concentrating. Headache and nausea were also reported. A statistically significant difference was not found between reported effects from high-exposure and medium-exposure workers, although the incidences were significantly higher than in the non-users (McConnell et al. 1987).

This article from Field & Stream I think summarizes the matter best: there is no real consensus about the issue of DEET, and no singular authoritative voice on the subject. On a personal note, I avoid DEET almost entirely because I'd rather deal with insect bites (and take anti-malarials when traveling) than risk exposure to something potentially toxic to my central nervous system.

Finally, I've never come across any literature that says what medium of repellent is most effective (spray v. lotion). I think the concentration of the active ingredient is more likely to affect the product more than its viscosity.

P.S. My uncle has a hiking friend who swears that taking cayenne pepper capsules is the best insect repellent. I'm not really sure if there's anything to back that up.

  • 1
    Maybe you like my answer. I thought DEET was worldwide prohibited. It's a powerful poison, hit plants, animals, humans, and stays on the life cycle for so many years.
    – H_7
    Oct 1, 2011 at 12:04
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    @H_7 Um, you're thinking of the infamous insecticide DDT (still in limited use). Totally different. Mar 22, 2015 at 0:32
  • Interesting study in reported in TIME suggests 15% DEET is more effective than higher concentrations, and that 20% picaridin or 30% oil of lemon eucalyptus might be more effective still. Also, I've asked about catnip on Skeptics.SE Feb 4, 2016 at 11:11

100% DEET is certainly very effective, but it's hard on your skin. Try it but be prepared to back down to 25% or even 7%.

  • Deet works best, according to write-ups I've seen.
    – xpda
    Sep 13, 2011 at 2:40
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    Also be careful of synthetic clothing (DEET can melt it). It also ruins painted fingernails - my girlfriend learnt that the hard way! Absolutely worth it if you can't afford to be bitten.
    – John Lyon
    Sep 13, 2011 at 6:32
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    @jozzas , I'm curious: where was your girlfriend that both malaria and manicures were matters of concern? Sep 13, 2011 at 10:30
  • @Malvolio The closest thing you can get to a resort in the Solomon Islands, a place called Sanbis. Highly recommended!
    – John Lyon
    Sep 13, 2011 at 22:10

Some coworker went to a jungle tour in Thailand for 4 days or so. He said not washing and wearing the same clothes for the whole time he was on the tour worked much better for him than all the mosquito repellents the other tourists used :)

True story!

  • 5
    Mosquitoes in different places seem to have different "taste". Sometimes I'll get attacked and not nobody else. In Bulgaria my friends were getting bitten but the mosquitoes would fly around me and not land and not partake of my blood. So maybe that's what happened with your coworker too and it was just a coincidence how icky he let himself become (-: Sep 12, 2011 at 21:42
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    The plural of anecdote is not data; certainly the singular isn't. Either your cow-orker wasn't to the local mosquitoes' taste or he wasn't allergic to the anti-coagulants in the moskies' saliva (which is what raises the characteristic itchy welt, without which you'll never notice the bite.) Sep 13, 2011 at 0:53
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    Wearing the same clothes the whole time is also a good way to repel other travellers, in addition to mosquitoes, I believe. Sep 13, 2011 at 9:12
  • Maybe it works for tropical mosquitoes, but for these nasty bloodthirsty bastards from Easter Europe it only works as an attractor.
    – Grzenio
    Sep 29, 2011 at 6:57

DEET is pretty much the mosquito repellant of choice. The more of it there is, concentration wise, the less pleasant, so scale your concentration based on the risk of mosquito-borne disease.

"Backyard party with friends" - probably a pretty low concentration. "Hell no, I will not be getting malaria while in Uganda" - I used 95% DEET. Stuff was vile, but it worked.


I live in a tropical country with a lot of mosquitoes in some beaches I regularly visit. The best mosquito repellent I know is all natural.

It's vitamin B12. You start to ingest B12 capsules 2 weeks before travelling. Your skin will produce a natural protection with an odour mosquitoes really dislike. It's better than any spray, chemical or citronella candles... cheap and clean! Oh, sure, you can't feel the smell, only the mosquitoes!

  • @iHaveacomputer - Probably a true example of a person with high levels of B12 on blood.
    – H_7
    Sep 28, 2011 at 21:14
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    Is there research to back this claim?
    – MarkE
    Jan 31, 2014 at 19:39

I live in French Polynesia (tropical country) and I use monoi. I works very well against mosquitoes, you just have to put more every 3-4 hours. The mosquitoes here really like to bite the feet, especially when I'm working at my desk so I don't bother covering my whole body with monoi, just my feet and ankles.


Mosquitos find their quarry by detecting Carbon Dioxide that is emitted from the pores in the skin as well as breathing and sweating. The reason that Deet, Picardin, or any other repellant works is because it renders the targeted individual "invisible" to the mosquito. Citroenella candles, for example, mask and even combine with CO2, to render an individual or even a group "invisible". Once you understand this simple truth, you will see that by not bathing and not changing clothes you leave the pores in the skin mostly clogged with dirt and oil. This effectively cuts down on the amount of CO2 that you emit and the mosquitos can't find you.

  • Um, humans mainly emit CO2 by breathing, not through pores in the skin.
    – krubo
    Aug 17, 2018 at 3:03

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