Developed in the 1940’s by the U.S. government and originally intended to be a plant pesticide, there’s no denying the effectiveness of DEET (N,N-diethyl-meta-toluamide).
It does an excellent job at deterring not just mosquitos, but also biting black flies, ticks, fleas, and chiggers.
No one questions if it works, but many question its safety.
Mohamed Abou-Donia, Ph.D. of Duke University is perhaps the foremost researcher on the topic. He has spent some four decades studying pesticides and has published numerous pieces of research linking DEET to brain damage in rats (1).
“Damage to these areas could result in problems with muscle coordination, muscle weakness, walking or even memory and cognition.”
Even when rats were given the average human dose (40 mg per kg of body weight) it was found they had inferior muscle control and coordination (2).
Of course we are assured by governments that alternatives to DEET insect repellent are not needed, because it’s perfectly safe. Well if that’s the case, then why does our own Environmental Protection Agency (EPA) publish these warnings, as well as others, on their website (3):
“Use just enough repellent to cover exposed skin and/or clothing.”
“Avoid over-application of this product.”
“Do not use under clothing.”
“Wash treated clothing before wearing it again.”
“After returning indoors, wash treated skin with soap and water.”
If there are no safety concerns, then why such extreme warnings like that? Do you feel comfortable using DEET on babies or toddlers when reading that? The same isn’t said for other topical skincare products, like sunscreen.
Clearly, they must suspect dangers of DEET for such overt and aggressive measures to be instructed.
On the flip side, almost three-quarters of a billion people get infected by mosquito transmitted illnesses every year (4). Even if DEET is dangerous, so are infections of malaria, Zika virus, yellow fever, dengue fever, and chikungunya.
Perhaps that’s why governments feel obligated to continue recommending DEET and say it’s safe… because the benefits of it seem to outweigh the potential risks.
In the past such a stance may have made sense, but in recent years, DEET free mosquito repellents have come on the market that actually work. Sure, they may have drawbacks, like being expensive and not lasting as long on the skin, but for many health conscious consumers, that’s a small price to pay for the avoidance of an alleged neurotoxin.
Among the many alternatives, which work the best?
Online reviews are helpful, but they’re not always trustworthy. Nor are they always analogous to your needs. What works in Michigan or Canada may not suffice for an African safari.
Consumer Reports rankings are often cited as the go-to source, but they don’t seem to be concerned with DEET. Many of their top rated insect repellents contain 15% to 30% DEET.
Furthermore, how they test is more of a lab experiment. It’s not real world scenario. Here’s how they describe it (5):
“Our brave testers stuck their arms into cages full of disease-free female mosquitoes in need of a blood meal to lay their eggs, and then watched and recorded bites for five minutes every hour. A repellent failed if a tester was bitten two or more times in one 5-minute session, or once in two consecutive sessions.”
We’re not saying that methodology isn’t helpful, but as you already know from medical research, what works in the lab doesn’t always translate to what happens in the real world.
Our testing is not a controlled experiment, but it is an extreme real-life scenario; southern Africa during the wet season. In February, which is their summer. The locations were remote and harbored heavy insect populations:
Botswana – In the Okavango Delta region, throughout the private 500 square mile Selinda reserve.
Zambia – On the banks of the Zambezi River, in Mosi-oa-Tunya National Park.
South Africa – Sabi Sands reserve, where you will see little sand and lots of watering holes at this time of year.
The female Aedes aegypti mosquito is infamous for spreading the Zika virus. While it is found in these regions, Zika was the least of our worries. Malaria is of much greater concern for non-pregnant women and adult men, as long as they’re not in the process of impregnating women (6).
Which products/ingredients we tested
With the exception of Livingstone Airport, which is near the Zambezi river, all locations required travel by small prop planes. How much luggage that’s allowed on these is less than your standard domestic carry-on suitcase:
- One hand bag (e.g. purse or backpack for carrying in lap)
- One small duffel (no rollers, 24” x 12” x 10”)
- 33 lbs. for the combined weight of both (consider that photography equipment eats up at least one-third of that)
The commercial flights from Southern California to Johannesburg involved only carry-on bags, so there was just a quart-sized bag of liquids per passenger.
Obviously, that meant being selective in which products we brought on safari, especially since a half-month of living had to be packed into that luggage!
After extensive research, the following is what was settled on and coincidentally, the choices were all related to food.
Wild sage (Pechuel-loeschea leubnitziae)
This one was a no-brainer, because we didn’t need to bring it!
Also known as stinkbush and bitterbos, it grows abundantly throughout these regions, especially in northern Botswana. The locals consider this plant to be the best natural mosquito repellent for the yard and bedroom, by making a fire or incense out of it.
Picaridin (same thing as icaridin)
While the definition of organic is legal, the meaning of natural is largely subjective. That’s why marketers call everything “natural” nowadays.
Natrapel spray uses 20% picaridin. Despite its name and the marketing verbiage of similar repellents, picaridin is not natural. However, it’s the next best thing; it’s molecularly identical to a compound found in the essential oil of black pepper (piperine).
Since picaridin is functionally identical to a naturally occurring amino-acid, it’s registered with the EPA as a biopesticide (a pesticide derived from natural materials, i.e. plants) rather than a chemical pesticide (like DEET).
Whether you buy Sawyer picaridin insect repellent lotion, Natrapel spray, or any other brand, all use a lab-created version of this compound.
That’s probably a good thing.
Aside from the expense of doing so, trying to isolate this compound from natural piperine would involve chemical solvents, whose residue would inevitably get left behind.
Is picaridin safer than DEET? Just because something is natural (or identical to natural) that doesn’t guarantee safety. That said, the same nerve toxicity dangers which been widely suspected with DEET have not shown up in the research about picaridin side effects, at least so far.
Skin irritation from picaridin is rare. It’s considered “practically nontoxic” if inhaled. Only when rodents were fed large doses were their kidneys and livers affected. Based on animal studies, there is no evidence to suggest that picaridin causes cancer (7).
Two forms of repellent were tested which contained this ingredient:
Natrapel 20% spray
This is marketed as being an 8-hour treatment that claims to have “long lasting effective mosquito and tick protection.”
It’s conveniently sold in a 3.4 fl. oz (100mL) bottle which is approved for carry-on baggage.
Natrapel 20% individually-wrapped wipes
These were actually leftover from a prior expedition to Tanzania. Bringing wipes is an allowed trick for legally circumventing the liquid limitation at the airport, as you aren’t required to put wipes such as these in your quart-sized Ziploc bag.
Avon Skin-So-Soft Bug Guard + 10% picaridin towelettes
Not even under the most liberal definition would these ever be considered a natural or organic insect repellent. It contains plenty of chemicals which are not bioequivalents of anything found in nature. That being said, Skin So Soft is a good alternative to DEET for mosquitoes and flies.
It gained notoriety during the 80’s and 90’s as being the only thing that really worked for biting black flies in the upper peninsula of Michigan. Avon bought them out and now the brand is mostly marketed for beauty/cosmetics, but it’s still the same scent that bugs – especially flies – seem to hate.
We brought these along to compare and contrast versus straight up picaridin wipes. Plus, anything sold as a prepackaged wipe frees up valuable real estate in that quart-sized liquid bag (the mineral-based sunscreen already occupies half that space).
Lemon eucalyptus essential oil
The Corymbia citriodora tree is native to northeast Australia and also goes by the names lemon-scented gum, blue spotted gum, and eucalyptus citriodora.
There is actually a manna-like substance which some people scrape off the leaves and eat. Though as with other food-related ingredients, eating them would do nothing to deter insects from biting you.
Reviews of Repel insect repellent may not be what you expect here, since the majority of their products are the old-school DEET foggers, sprays, and lotions. They do make one product which is a 100% natural bug spray that’s plant-based. Its active ingredient is oil of lemon eucalyptus (30% concentration).
Repel is listed on Consumer Reports’ top insect repellents ranking at #3, with the top 2 being DEET and picaridin. So according to them, the top natural choice would be the lemon eucalyptus.
Now whoever thought up the packaging for this product is an idiot. The smallest size it’s available in is 4 ounce (118mL), which exceeds the 3.4 ounce maximum for carry-on liquids.
You may think that extra 0.6 oz. is too trivial to make a difference, but it actually does.
Good luck connecting at London Heathrow with that bottle, as they will scrutinize anything and everything.
Both coming and going from Africa, the buffoons at LHR checked the sizes of every liquid container in the bag. And no, they weren’t “just doing their jobs” as their snide remarks were unnecessary and the cited rules were actually contradictory, varying by agent.
Fortunately, the LHR imbeciles were already anticipated prior to departure, which is why the lemon eucalyptus oil insect repellent was re-packaged in another 3.4 oz/100mL spray bottle.
Products we didn’t test (and why)
Active Ingredients: geraniol 5%, soybean oil 2%, sodium lauryl sulfate 0.4%, potassium sorbate 0.1%
All Terrain Herbal Armor
*There is also Kids Herbal Armor spray, but both versions have the same active ingredients and percentages.
Active Ingredients: oil of soybean 11.5%, oil of citronella 10.0%, oil of peppermint 2.0%, oil of cedar 1.50%, oil of lemongrass 1.00%, oil of geranium 0.05%
Ecosmart Organic Insect Repellent
Active Ingredients: geraniol 1.0%, rosemary oil 0.5%, cinnamon oil 0.5%, lemongrass oil 0.5%
California Baby Natural Bug Blend
Active Ingredients: 5% citronella, 0.5% cedar, and 0.5% lemongrass essential oils
Burt’s Bees Insect Repellent
Active Ingredients: castor oil 10%, rosemary oil 3.77%, lemongrass oil 2.83%, cedar oil 0.94%, peppermint oil 0.76%, citronella oil 0.57%, clove oil 0.38%, geranium oil 0.19%
The reason these were ruled out, at least for this expedition, was because these products have mediocre to downright terrible reviews.
Those were the only natural bug deterrents tested by Consumer Reports and their scores ranged from 7 to 29 (out of 100). Yes, they were agnostic to favoring DEET vs. non DEET sprays, but they still gave Repel lemon eucalyptus an 87 out of 100. That was the best natural spray according to them, since their 2nd was only 29 (Cutter Natural).
For those wanting an organic mosquito repellent, the only readily available choice is the Ecosmart brand. That was also Consumer Reports’ worst-rated bug spray with a score of only 9.
Regardless, we would be happy to give that a try in the Canadian backwoods, but not the African bush during the wet season. With the former, you’re more worried about the bugs being a nuisance, with the latter, it’s catching diseases like malaria or the immensely under-reported Dengue virus/hemorrhagic fever (8).
Plus, it’s worth mentioning that antimalarial medications were not used on this trip. Preventive use of malarone (atovaquone/proguanil) has caused horrific side effects for us in the past.
Given that one of us already has permanent gastrointestinal and kidney damage from a past traumatic injury, the doctor said the benefits vs. the risk of malarone weren’t worth it for his circumstance (though you should take it if your doctor advises).
In short, when you’re camping 30 miles from the nearest road in the wet Botswanian backlands, it’s not the time or place to experiment with poorly-rated products. You need to use those which are most likely to be effective DEET alternatives.
How we tested
This was not a controlled science experiment. It was a straightforward “what works and what doesn’t” whereas each of the products was tried on different days, in the different environments.
- One person evaluated on a quantitative basis, by actually counting bites.
- One person took a subjective stance, by estimating how many insects and which types tended to congregate around his body, based on which product he was wearing.
- On a given day, each person used none, one, or multiple products (to test combinations).
How often the repellents were applied would vary:
- In the morning, at around 6 am before heading out for the day.
- Re-applied in the mid-afternoon or on an as-needed basis (some products lasted longer than others).
- Re-applied in the evening at around 7 pm, prior to dinner.
- In each of the three countries, on at least one-day, there was no repellent used (for comparative purposes).
- The wild sage was a repellent for the yard/campsite and only tested in Botswana.
The trip was a half-month and almost identical amounts of time were spent in each region of Botswana, Zambia, and South Africa. This provided an equal number of testing opportunities for each.
These photos will give you a good idea of the environments in which these products were tested. Please be aware that graphic imagery of a lion’s kill is below.
A truly organic remedy! Matt holding a stalk of wild sage and sharing how to make your own natural mosquito repellent using it. More on that at the end.
This lioness killed this wildebeest and its carcass was monitored for two days. She and her sister would move it around periodically, sometimes laying it in a bush of wild sage (like above). Hundreds, if not thousands, of black flies set up shop on the kill – even when it was laying on that species – so that plant appears to have no deterring effect on flies.
In this region, the flow of the Okavango river stops, which creates the swampy Okavango Delta. As a result, you don’t have to travel far to find a pool such as this. Still water is where mosquitoes (and hippos) love to breed.
The Zambezi is the longest east-flowing river in all of Africa. Its creates Victoria Falls, which is just a couple miles up from this location.
Despite its power, there is plenty of marshy standing water along the river banks, as pictured above. Hot weather with still water and shade is the ideal environment for those pesky two-winged insects – millions of larvae are in there. Literally two feet behind this photo are our sleeping quarters, and hence, the importance of bug spray!
How to use picaridin, citronella oil, and lemongrass as mosquito repellent is all the same. Spray on all exposed areas of skin and for better results, apply under the collars of shirts. It’s also a good idea to use on the areas of clothing adjacent to your exposed skin, such as your sleeves and hat. If you’re not wearing a hat, spray your hair which is an area most people forget. Even if a repellent is non-toxic, you should avoid breathing the mist and avoid spraying in the direction of your mouth and nose.
Studying white rhinos a couple miles inland of the Zambezi, you will see no ponds in this area. However being that it rains almost everyday during their summer, there are still plenty of standing puddles in this area for mosquitoes to have their love fest.
Directly adjacent to Kruger National Park is the Sabi Sands reserve, a private parcel of land which is a whopping 250 square miles of pristine wilderness.
But don’t be fooled by the name. In the summer it rains plenty, so you will actually see very little sand, and lots of foliage plus water.
In fact there’s so much foliage, animals you’re looking for seem to pop out of nowhere…
At times like these, no need for a fancy camera. An iPhone will work just fine.
In case you’re wondering about danger, the suspected side effects from using DEET are exponentially scarier than what you see pictured above. Rhinos have horrendous vision. When you’re downwind like this, you can be right next to them undetected. Believe it or not, this is actually a safe situation, relatively speaking.
Off topic – See that brown leather flap on the right side of the phone’s screen? That’s the top anti-radiation cell phone case on the market (highly recommend it).
The flies were much worse in this region, but there were fewer mosquitoes than Botswana and Zambia.
Which repellent worked best?
Half of a month in three remote regions of southern Africa during the hot and wet summer season. Reviewing natural repellents for mosquitoes and flies doesn’t get more real world than this. So which sprays worked and which were a failure?
If you’re only going to use one product, there was mutual agreement that a 20% picaridin spray is your best, most effective alternative to using DEET. For mosquitoes it seemed to work comparably and when it came to biting black flies, the picaridin may even work better than DEET.
Not only would we recommend it for the places in this safari, but it’s also the top bug spray for Kenya, Tanzania, Thailand, Costa Rica, Australia and just about everywhere else. For tropical climates with more of the Zika carrying Aedes species, it’s a reliable alternative.
The lemon eucalyptus oil repellent really works for mosquitoes, but not as well as picaridin. It required re-application every 2 to 3 hours and even with that, it only was about 80% as effective as picaridin.
It also had a major drawback for one person – an allergic reaction. While not serious or life threatening, the nasal allergies were a side effect bad enough to warrant discontinued use of the Repel lemon eucalyptus. At least for that person, after Botswana.
Even though both can work well for adults, when it comes to babies and young children, it would be wise to consult a doctor before using picaridin, lemon eucalyptus, or any other product.
If you want the ultimate protection, it turns out a multipronged approach will be the way to go. From the person among us who was actually counting bites:
“I only had four mosquito bites total throughout the trip while using this method. One bite on the back and the other three were at the bottom of my legs, where admittedly I was using less protection. First I would apply both sprays as an overall protection, to cover my outer self. Then I relied on the wipes, folding them into my collar after application. They stayed fragrant and moist for many hours, even until the evening.”
That’s right, Avon Skin So Soft works as bug repellent even if it’s not on your skin. Since it’s not natural by any stretch, you may not be a fan of applying it topically. Still, you should at least consider folding the moist wipes into your shirt collar and/or breast pocket.
What’s the best organic mosquito repellent?
Even though it’s natural chemical, all picaridin sprays use a synthesized form of it and therefore, none will be organic.
The lemon eucalyptus oil in the Repel spray is not organic, nor are the inactive ingredients in it.
While not perfect, EcoSMART brand is the best organic repellent, or among them, given that it uses proven essential oils. It’s worth a shot, as long as you don’t need DEET-quality performance.
You can buy EcoSMART on Amazon.
One of the reasons it may not work well is because the essential oils only represent 2.5%. The other 97.5% consists of inactive ingredients.
You may want to try to make your own natural mosquito repellent from plants by purchasing those same essential oils separately and using them in a higher concentration. They won’t be certified organic, as essential oils rarely are, but at least you will be in control of what you’re putting on your skin.
For an affordable science experiment, you can find each of those oils on Amazon:
If you want a homemade repellent for your backyard or campsite that you don’t wear, then the wild sage we were talking about might seem like a good idea. In Botswana, they burn a small ball or bound stick of it. The resulting scent seems to work, even after extinguishing.
Unfortunately, that won’t be an option for you.
The wild sage found in Southern Africa – Pechuel-loeschea leubnitziae – is a unique species.
It’s not part of the Salvia or Artemisia genus. Those encompass dozens of species including clary sage, nettleaf sage, sagebrush, and dozens of other plants you may call sage. Even African sagebrush (Artemisia afra) is from a totally different genus than what the locals call wild sage in Botswana.
We can’t find Pechuel-loeschea leubnitziae for sale online in any form. Not even the seeds to grow your own.
So unless you live in South Africa, Namibia, or Botswana and can go harvest some yourself, this home remedy won’t be an option for you.
3-part approach for max protection
If you want a bug spray that doesn’t contain DEET, the following three-part approach will be your most effective strategy for combating mosquitoes and flies.
Wear a 20% picaridin product on exposed areas of skin.
If you’re not allergic to the smell of lemon eucalyptus, then use Natrapel too.
Use the wipes in combination with a spray/lotion. Ideally, the Skin So Soft brand of wipes.
Even if you’re on the fence about picaridin, there are ways to wear it without it ever touching your skin…
Hang the wipes out of your pockets, stuff into collars, hang on your backpack, and more. They will stay moist and repel bugs throughout the day.
You can get the Natrapel wipes on Amazon. Those are a 20% picaridin strength.
Even though they’re weaker with 10% strength, we actually prefer the Avon Skin So Soft Bug Guard towelettes. They’re much bigger and longer-lasting. The scent offers a 2nd line of defense against not just mosquitoes, but also deer ticks, gnats, no-seeums, biting midges, sand flies, and more.
Regardless of whether you’re using synthetic, natural, or organic repellents, the ultimate barrier to stop bugs will be a physical one.
Of course, you can’t cover your entire body and face with clothing.
Well actually, you could…
But that’s a bit extreme, don’t you think?
However the hoodie you see pictured above is the same one as the other photos in this review. Several have been taken on safaris to Africa and elsewhere.
- Tightly woven fabric provides UPF 50 protection against the sun.
- Because it is tightly woven, it’s harder for bugs to bite through.
- Thumb holes at the end of the sleeve allow for optional coverage of your hands.
- Even on hot days, this unique fabric is cooler to wear than a T-shirt thanks to its embedded xylitol, which can decrease the fabric’s temperature by up to 5°F.
And no, you don’t have to zip it up all the way to cover your face (unless you want to).