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 bug repellent is most effective against mosquitoes? 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.).

  • 1
    Suggest starting a different question for types of repellent, since the answers below treat the stated question. Most effective = DEET. Ooops - someone already did: outdoors.stackexchange.com/questions/978/…
    – Lost
    Commented Feb 8, 2012 at 2:06
  • 2
    I use 100% DEET and love it, but one issue with DEET that has not been mentioned in the answers is that is dissolves most plastics. For example, people often damage their car's steering wheel or dashboard by finishing a hike and driving away with 100% DEET on their palms. It will also dissolve the plastic of many brands of bear canisters.
    – user2169
    Commented Dec 7, 2013 at 22:42

4 Answers 4


Mosquitoes love me, so I've had opportunity to try many variations of repellent. Most of the things you mentioned are effective immediately after application. For me, the difference is how effective they are after hours of sweaty hiking. For that, I lean towards high percentage DEET in a lotion-type formulation like 3M Ultrathon (that particular one is 35% DEET).

For the parts of you that are covered by clothing, I have had success with permethrin treatments, but I prefer just wearing clothes that mosquitos can't bite through (I don't know how to find this out without field testing).

DEET is supported by several studies

Annals of Internal Medicine

N,N-diethyl-3-methylbenzamide (DEET) is the most effective, and best studied, insect repellent currently on the market.


Of the active ingredients registered with the EPA, CDC believes that two have demonstrated a higher degree of efficacy in the peer-reviewed, scientific literature (See Publications page.). Products containing these active ingredients typically provide longer-lasting protection than others:

DEET (N,N-diethyl-m-toluamide)
Picaridin (KBR 3023)

Also make sure you apply sunscreen first.

EDIT: I suppose I should be clearer? nothing is more effective than DEET :) Sure it might melt your face off, but if the alternative is not going outside, I choose melty-face.

  • 1
    +1 for answering the stated question: "What type of mosquito repellent is most effective"
    – Lost
    Commented Feb 8, 2012 at 2:00
  • Permethrin is more effective on ticks than on mosquitoes. Mosquitoes will typically bite you regardless of the permethrin, and will only die after they fly away. Also, permethrin is environmentally not so good. It kills fish, mice, and cats.
    – user2169
    Commented Dec 7, 2013 at 22:35
  • Two comparisons I've seen are from a NPR article and REI Commented Oct 30, 2016 at 18:49

The CDC says Picaridin and DEET* are the best, with Oil of Lemon Eucalyptus** being something of a shorter-lasting runner-up:

Of the active ingredients registered with the EPA, CDC believes that two have demonstrated a higher degree of efficacy in the peer-reviewed, scientific literature (See Publications page.). Products containing these active ingredients typically provide longer-lasting protection than others:

  • DEET (N,N-diethyl-m-toluamide)
  • Picaridin (KBR 3023)

Oil of lemon eucalyptus [active ingredient: p-menthane 3,8-diol (PMD)], a plant- based repellent, is also registered with EPA. In two recent scientific publications, when oil of lemon eucalyptus was tested against mosquitoes found in the US it provided protection similar to repellents with low concentrations of DEET.

*I think it is important to note that 100% DEET is overkill:

DEET efficacy tends to plateau at a concentration of approximately 50%.

**: Caveat emptor:

“Pure” oil of lemon eucalyptus (essential oil) is not the same product; it has not undergone similar, validated testing for safety and efficacy, is not registered with EPA as an insect repellent, and is not covered by this recommendation.

Their full list also includes IR3535:

  • DEET (Off!, Cutter, Sawyer, and Ultrathon)
  • Picaridin (Icaridin) (Cutter Advanced, Skin So Soft Bug Guard Plus, and Autan (outside the United States))
  • Lemon Eucalyptus oil (PMD) (no examples given)
  • IR3535 (Skin So Soft Bug Guard Plus Expedition)
  • 1
    The point of 100% DEET is not that you want more effectiveness, it's that a given amount of DEET at high concentration means less weight in your pack than the same amount of DEET mixed with alcohol. 100% DEET can be conserved on long hikes by the following procedure. You pour some water in your palm, add a tiny amount of DEET (as low as 1 part DEET to 20 parts water). Then mix them up and smear them on. Although DEET is not soluble in water, the mixture stays emulsified long enough for you to apply it.
    – user2169
    Commented Dec 7, 2013 at 22:39

DEET can be harmful to the skin if you suffer from any skin disorders such as Eczema (as I do).

I have recently started using a product called Smidge when hiking in Midge infested areas of Scotland. More details can be found here. The manufactorers claim it works on a variety of biting insects including Midges, Ticks and Mosquitoes. It does work with Midges! I'm going to see if it works on Mosquitoes when I go to SE Asia later in the year!

I have in the past also used Repel 55 Insect Repellent Spray when travelling in Latin America and that seemed to work okay.

  • +1, especially relevant to me as I also suffer with eczema!
    – berry120
    Commented Jan 31, 2012 at 16:09
  • 2
    Downvote because this promotes a product you've never used against mosquitos based purely on the manufacturer claims and hence does not really answer the question. Do you have any independent support for the effectiveness? (just find independent validation and i'll remove the downvote) Commented Feb 7, 2012 at 22:44
  • It is difficult to find any independent review as it is a relatively new product and is marketed really for midges and ticks in Scotland. Gearweare (gearweare.com/review/smidge) have a review of the product but they do not go into effectiveness specifically on mosquitoes. There are a few forum posts as well. I'll let you know how effective it is!
    – Aim Kai
    Commented Feb 8, 2012 at 7:49
  • @AimKai -- I sympathize with the difficulty. New products often take significant time to be thoroughly vetted against manufacturers claims. Commented Feb 8, 2012 at 23:26
  • By the way I tested this out in April, in the south of Vietnam, and it is reasonably effective, in the sense that in particular bad areas it is similar to other products and has limited scope to repel. I personally prefer to use something like this because of my eczema.
    – Aim Kai
    Commented Jun 26, 2012 at 8:32

I wanted to add some points to the discussion, as well as list another product.

First, as noted, 100% DEET is overkill. Once you go over 35%, it doesn't get better. Second, DEET is not good for you. Not saying don't use it, but try to use the minimum needed.

What I like to use is permethrin. This is used on gear and clothing, not skin, and stays active for months. Once dry, it is odorless, colorless, & leave no residue that can be felt. And doesn't wash off. It's mostly an insecticide that kills insects that touch it, but I have found that it also works as a repellent as well. Not as good as DEET, but usually enough so I don't need the DEET.

Although it's sold in small containers in outdoor stores and departments, you can get it in a concentrate online that's much better deal.

  • FWIW, I did mention permethrin briefly in my answer... and that ultimately I just prefer to wear mozzy-proof clothes :)
    – Ryley
    Commented Dec 12, 2013 at 22:36
  • Yeah, missed that. I see it now. Commented Dec 13, 2013 at 3:33

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