Mosquito repellents

Which repellents keep the mozzies away?

Close-up of young tourist applying mosquito spray on arms.

Nothing puts a dampener on a barbie or camping trip like a mozzie nipping at your ankles or buzzing in your ear. We tested 17 repellents, including four natural products, to see which ones will keep you bite-free this summer.

When it comes to mozzie sprays, products with diethyltoluamide (DEET) are known as the gold standard. However, some people don’t like how it smells and feels on their skin. It can also damage some fabrics and plastic items such as sunglasses.

Some consumers are also concerned about the safety of DEET. A survey conducted by US consumer organisation Consumer Reports found 25 percent of Americans said they avoided using repellents with DEET. About a third of respondents said they thought DEET products weren’t as safe as the alternatives.

So how do the alternatives stack up? We tested four natural products containing plant oils, four picaridin-based products, and nine DEET products to find out.

What we found

The DEET-based products we tested contained between seven and 40 percent of the active ingredient. Some of these DEET products also contained other active ingredients (see “Mosquito repellents” table).

Close-up of person's arm with a dead mosquito on it, by swimming pool.

All tested products containing DEET performed similarly regardless of how much the product contained, and repelled mozzies for up to six hours (which is how long we tested effectiveness for).

It was a similar story with picaridin repellents. Products with picaridin were good at repelling mosquitos regardless of concentration. Off! Family Care (9.5 percent picaridin) was as effective at repelling mozzies after four hours as Off! Tropical Strength with nearly double the picaridin.

Bug Grrr Off Natural Personal Insect Repellent Jungle Strength was the only natural product to go the distance. It was as effective as the DEET and picaridin-products. With 36 percent lemon eucalyptus oil, it kept mozzies at bay for six hours. In comparison, Repel OLE! with the same active ingredient, lost effectiveness after one hour. The label didn’t specify the percentage of active ingredient.

Thursday Plantation Walkabout Insect Repellent Roll-on contains plant oils, including tea tree (melaleuca) and citronella. It provided 90 percent protection for two hours and kept the majority of mozzies away for six hours.

Goodbye Sandfly Repellent + Bite Soother, with a combination of essential oils, was very good at initially repelling mosquitoes, but its effectiveness wore off more quickly than other products.

John Sanderson, co-owner of Goodbye Sandfly said its product works differently to a chemical repellent and was mainly developed to deter sandflies.

“It can take up to 60 seconds for the heat of your skin to begin evaporating the oils. Once the oils are evaporated there is no more protection. To get the best results, Goodbye Sandfly should be applied frequently in small amounts. This might be as often as every 20 minutes, but usually every one to two hours. This will depend on the weather and what activity people are doing,” he said.

We also tested two insect repellent-sunscreen combos from Bushman and Rid. We’re not fans of these products – sunscreen should be reapplied every two hours, whereas repellents usually last for several hours. If you need to use repellent and sunscreen together, it’s best to apply the sunscreen first, let it dry, then put on the repellent.

What’s in them?

The Health Navigator Charitable Trust website lists DEET (diethyltoluamide), picaridin, IR3535 and oil of lemon eucalyptus (also known as OLE or PMD) as providing reasonably long-lasting protection.

DEET is referred to as the “gold standard” for repelling mozzies. The US organisation Centers for Disease Control and Prevention (CDC) states DEET is safe to use as long as you follow a product’s directions.

DEET isn’t recommended for babies younger than two months and products with more than 30 percent shouldn’t be used on children. Some people could experience skin problems, especially if used in high concentrations or in large quantities for several days.

DEET can damage some synthetic fabrics, as well as plastic and leather, and some people don’t like the smell. When it comes to the environment, it’s OK to use. DEET gets into the air when you spray, but the chemical is broken down by sunlight and air. In water, DEET is degraded by aerobic microorganisms.

Bottle of essential oils with a leaf of lemon eucalyptus.
Oil of lemon eucalyptus is the most effective natural product.

Picaridin is based on a molecule found in the black pepper plant. It has little odour, doesn’t feel sticky or greasy, and is less likely to irritate the skin. Products containing 20-25 percent are recommended as being effective. Picaridin isn’t recommended for children younger than two years.

Oil of lemon eucalyptus is the most effective natural product. It’s not recommended for children younger than three years.

Some natural products contain plant oils with known insect-repelling capabilities such as citronella, melaleuca, lemongrass, eucalyptus or lavender. These oils have an initial repellent effect, but it diminishes quickly so these products need to be regularly reapplied.

Our test

To test repellency, each product was tested on four people in an independent laboratory. Each person had a repellent applied to their forearm according to the directions, before placing it in a cage containing approximately 40 unfed mosquitoes. Cages are specially constructed out of clear plastic for easy viewing and fine polyester netting for ventilation.

At set time intervals (up to the amount of time a product claimed to be effective with a maximum of six hours), volunteers exposed their arm for three minutes and the number of attempted and successful landings were recorded. An attempted landing was when a mosquito touched the forearm but didn’t remain there. A successful landing was when a mosquito landed and remained for more than one second, before being shaken off by the tester.

Before the test, each volunteer exposed an untreated arm to the mosquitoes. There was no significant difference in the number of attacks during the control trial.

Our test was tough – you’re unlikely to find that many mozzies in close proximity out and about. How long a repellent lasts also depends on the conditions and what you’re doing – sweating and swimming will shorten protection time. All our tested products also claim to protect against other annoying bugs, but we didn’t test this. Repellent effectiveness can vary between insect species, including different mosquito species.

Natural oil-based repellents compared

Tips for using repellents

  • Apply repellents evenly to all areas of exposed skin. Reapply if you go swimming or sweat heavily. Don’t apply repellent to broken skin.
  • Don’t apply aerosols or pump sprays directly on to your face. Spray them on your hands first and then rub on evenly, avoiding contact with your eyes and mouth.
  • Don’t use near food, and wash hands after applying and before eating or drinking.
  • Before using a repellent on your baby or child, check that it’s suitable for their age. Use netting on prams, cots and play areas to avoid bites.

Protection overseas

New Zealand mozzies don’t carry diseases, but it’s a different story in other countries. Malaria, dengue fever, yellow fever and zika are some of the illnesses spread by biting insects.

Dr Yvonne Partridge a travel medicine specialist strongly advises those travelling overseas to use insect repellent and other measures to avoid bites. Dr Partridge recommends a 30-40 percent DEET repellent or 20-25 percent picaridin product.

“These should provide protection up to six to 10 hours”, she said.

“Oil of lemon eucalyptus is an approved natural repellent alternative to DEET or picaridin. But repellents based on plant-based oils such as citronella shouldn’t be relied on where there’s a risk of insect-borne disease.” Dr Partridge said.

To minimise the amount of repellent required, travellers should cover up with long-sleeved shirts and trousers when outdoors and sleep under protective netting or in air-conditioned accommodation. For added protection, permethrin can be sprayed on clothing, mosquito nets or sleeping bags. Permethrin kills mosquitoes and ticks, is safe and doesn’t stain. The effect lasts for about 10 washes on clothes or six months on mosquito nets and sleeping bags. Some tramping equipment comes pre-treated with permethrin.

Dr Partridge says there’s no evidence you will repel mozzies by taking vitamin B, eating marmite, yeast or garlic, or wearing mosquito-repellent wristbands.

“Wristbands (even those containing DEET) are of limited benefit because they only protect the skin near the wrist,” she said.

Member comments

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Wayne Hargreaves
08 Nov 2020
Repel Ole! Oil of Lemon Eucalyptus

I highly recommend this natural product which is made in NZ.

My wife & I travelled to Peru which included a river boat trip on the Amazon.

We used Ole! Oil of Lemon Eucalyptus which I found through my research on the USA FDA site for recommended mosquito products and was really happy to find it is a NZ product and can be purchased via the Repel website or our local Unichem pharmacy.

We did not get bitten at all in the Amazon - except the one time my husband quickly left the cabin for something and hadn't put the product on - which proved its effectiveness.
We also found it lasted as long as it was on the skin and not washed off.

On the Amazon river boat they asked you not to apply Deet products in the cabin due to it 'melting' the mahogany finish on the walls.

It does have a strong scent - but this is not unpleasant and we use it all the time now as we all of our family are magnets for biting insects.

Janet C.
07 Nov 2020
Vitamin B

I first learned about Vit B when my intermediate aged son was going on a school trip to Samoa. He and I are the unlucky magnets for mosquitoes. For two weeks before he left I dosed him up with Vit B morning and night, and packed him off with instructions to take them every day. Of course, being a boy, he took none. When they returned, the other kids were covered in “wall to wall” mosquito bites. Our son had about five, and commented that he didn’t get bitten until the last day. That was proof enough for me. In the twenty or so years since then I keep them in my travel bag. In fact I’m currently on Great Barrier Island, with everyone sleeping under mosquito nets. We haven’t been bothered by them at all, despite seeing them around.

Patricia J.
07 Nov 2020
vitamin B

When I lived on the West Coast taking large doses of Vitamin B2 did definitely repel mosquitos but had no effect on sandflies.

Barb S.
01 Nov 2020
Insect repellent

How does Picardin compare to DEET?

Peter K H.
01 Nov 2020
Environmental Concerns

There are some areas in the world where people are specifically asked not to use repellents containing Deet if they are going swimming because it is not good for the environment.

Trudy S.
31 Oct 2020
100% Natural Insect Repellent from The Herb Farm "Zoe's Bugs Away Kawakawa Spray"

This product is EXCELLENT!!! The Herb Farm have "Zoe's Bugs Away Kawakawa Spray". Made in New Zealand, it is 100% natural and available at www.herbfarm.co.nz This is the best insect repellent that I have found yet. It is a spray on and I can highly recommend it

Julie V
31 Oct 2020
"Repel" Tropical Strength is fabulous

I find Repel Tropical Strength (roll on) to be fabulous. It's main ingredient is DEET. I'm a photographer and take a lot of fungi shots in the bush, where mosquitoes are prevalent. I keep it in my camera bag and it's perfect. From the second I put it on my skin, mosquitoes stay away and I'm usually a person they love to bite. I'm usually out there for many hours at a time and the product lasts the distance well. I highly recommend it.

grace
31 Oct 2020
Insect repellant

where do you find this - the tropical strength Bug-grrr-off natural - i have been googling, and can find all the 'other' bug-grrr off products but not that one.... would be helpful to know!

Michele L.
31 Oct 2020
Looks like it is only available in Australia

Which means this article must be borrowed from the Australian publication of Consumer Magazine. I wish they could have done the test here and included some of our NZ natural insect repellents so that we could have had a heads up on how effective some of them are.....it would make the test results much more relevant.

Consumer staff
02 Nov 2020
Re:

Hi Michele,

Testing was conducted in Australia by an independent laboratory (there are no labs in New Zealand that can do this testing). Some New Zealand natural products were included in the test but it was not possible to test every product available.

Kind regards,
Belinda - Consumer NZ writer

grace
06 Nov 2020
Insect repellant

dont you think as we are members of Consumer NZ that you should have advised us of products we could actually get here? i feel that the products tested - the best ones should be those we can access

Peter I.
31 Oct 2020
New test results Table a HUGE improvement!!

Thank you Consumer for the new test results format as a table/chart. Far, far, far superior to either the side-scrolling results layout or the vertical-scrolling lists that required “Compare” boxes to be ticked. The chart & table are gold. Especially on a smartphone.

Your Highness
31 Oct 2020
Vitamin B

Back in the day I was in Fiordland for a month. I came prepared, with several bottles of vitamin b capsules. I took 6 times the therapeutic recommended dosage. It effectively kept the sand flies at bay, but also people.... I stank of vegemite! Mosquitos weren't around, so I can't say what effect my stinky odour had on them.

Martin N.
31 Oct 2020
Vitamin B1 or thiamine

I do think it works for some people and may actually be on prescription.