Natural Or Chemical Mosquito Repellents. Which Is Best For Travellers?

Editor’s Note: This is general travel health advice and is not intended to replace individual advice from your GP, specialist nurse or another qualified travel health professional, that has been tailored to your past medical history, medication or travel plans. This article was reviewed and updated on November 2026. It is routinely reviewed every 3 years unless new clinical evidence emerges.

Choosing a mosquito repellent for your gap year should be straightforward. You want something that stops you being eaten alive while you enjoy your trip, preferably without smelling like an industrial spill in a chemical factory. Instead, you’re faced with shelves of products promising everything from maximum-strength protection to an all-natural force field, alongside alarming claims that DEET is practically paint stripper. So which should you choose: natural or chemical?

Having worked in emergency nursing and travel and tropical medicine, as well as spent more than 25 years backpacking around the world, I understand why travellers want something that works without worrying about what they are putting on their skin. The good news is that effective options exist in both camps. DEET is an excellent choice, but there are reliable alternatives, including a plant-derived repellent.

The trick is knowing what you are buying. A properly formulated natural repellent with an effective active ingredient is very different from a homemade lemon-water concoction, however lovely it smells. Once you understand that distinction, choosing reliable protection becomes a lot easier — and you can get back to planning the enjoyable bits of your trip.

Natural Or Chemical Mosquito Repellents: The Quick Answer

For most travellers, a repellent containing 50% DEET is the first choice, particularly when visiting places where mosquitoes can spread diseases such as malaria or dengue. It is effective, extensively studied and has a strong safety record when used correctly.

If you prefer an alternative, 20% icaridin, also called picaridin, is a good option. Repellents containing PMD — a plant-derived ingredient that can also be manufactured synthetically — or IR3535 are effective alternatives too, although they generally need more frequent application than DEET.

So yes, a natural mosquito repellent can provide reliable protection, provided you choose a properly formulated product containing an effective active ingredient. That does not extend to every bottle labelled ‘natural’, essential oil blend or homemade concoction.

The useful question is whether the product contains an ingredient proven to repel mosquitoes, at an appropriate concentration, and whether you will use it properly. A pleasant smell and a picture of a leaf on the bottle won’t tell you that.

What Does ‘Natural’ Actually Mean?

Pick up a bottle of ‘natural’ mosquito repellent and you could be buying a useful travel health product or something that leaves you smelling lovely while the mosquitoes help themselves. The word alone has been so misused by less than scrupulous marketing departments and snake oil floggers that it is honestly meaningless.

Plant-derived repellents work because of particular chemicals found within those plants. One useful example is PMD, associated with the lemon eucalyptus plant. It is used in formulated repellents that provide effective protection against mosquito bites, and it can also be produced synthetically. On ingredient labels, you may see ‘Eucalyptus citriodora oil, hydrated, cyclized’.

This is different from simply putting lemon eucalyptus essential oil on your skin. A formulated repellent contains a controlled concentration of its active ingredient and has instructions for its use. An essential oil or homemade mixture cannot be assumed to provide the same protection just because it comes from the same plant or smells a little bit like lemon.

Unfortunately, ‘natural’ is also used to sell a great deal of wishful thinking. Homemade lemon water, herbal sprays and assorted essential oil concoctions are often promoted as alternatives to established repellents without reliable evidence that they will protect you adequately. Some plant oils do have repellent properties, but their effects can be too short-lived or inconsistent to make them a sensible choice, particularly where mosquitoes can transmit disease.

Homeopathic remedies have no reliable evidence supporting their use as mosquito repellents either. Calling something natural does not turn scented water into effective protection, however convincing the packaging or enthusiastic the recommendation.

There is nothing wrong with preferring a plant-derived product. Just choose a properly formulated repellent with a recommended active ingredient, rather than assuming everything on the ‘natural’ shelf does the same job.

Which Mosquito Repellents Actually Work?

There are four established active ingredients to look for when choosing a mosquito repellent: DEET, icaridin, PMD-based ingredients and IR3535. These offer effective protection when used correctly, but their concentrations, formulations and duration of protection differ.

Check the active ingredient on the bottle rather than choosing by brand name or the words ‘natural’ and ‘maximum strength’. Different products within the same range can contain different ingredients.

DEET

DEET is one of the best-established mosquito repellents and the first choice recommended in UK malaria-prevention guidance. If you want a straightforward starting point when shopping for your trip, look for a skin repellent containing 50% DEET. It has a strong evidence base and decades of widespread use behind it.

Despite that, some travellers feel uneasy about applying it regularly. Its chemical name can sound intimidating, and hearing that it can damage plastic understandably raises questions about putting it on your skin.

It is true that DEET can potentially damage some plastics and synthetic materials. This is a chemical reaction to specific types of plastic, not your skin. Keep it away from items such as plastic watch straps, phone cases or jewellery, and check before applying it to clothing. Apply it carefully to exposed skin, avoiding eyes, mouth and damaged skin.

DEET has a very different effect on your skin though. Many years worth of studies support a low risk of adverse effects when DEET is used correctly, and UK guidance supports its use during pregnancy and breastfeeding and for children from two months of age. Appropriate application remains important, particularly around children.

You do not need to buy the strongest bottle available. 50% DEET used correctly is highly effective at preventing mosquito bites for roughly 7 to 10 hours. UK guidance recommends 50% because increasing the concentration beyond that does not extend the duration of protection. Lower concentrations may need more frequent reapplication, while a 100% product does not offer the extra protection its larger number might suggest.

Of course like anything applied to your skin it can get wiped off through sweating or swimming which means it may not last the full 7 to 10 hours, but reapplying it sensibly still leaves you with the gold standard of mosquito bite prevention.

Icaridin Or Picaridin

Icaridin, also called picaridin, is a clinically tested mosquito repellent recognised in UK travel health guidance as an effective alternative to DEET. It is generally well tolerated, has little odour and does not damage plastics in the way DEET can, making it a practical choice when handling cameras, sunglasses and other equipment.

Choose a product containing 20% icaridin, the concentration recommended by UK guidance for reliable, lasting protection. Lower concentrations generally provide a shorter period of protection, so check the percentage rather than simply looking for icaridin somewhere in the ingredients.

Be aware that there are some combination products like sunscreen that list Icaridin as an ingredient. Regardless of what strength it says it is, combined products can dilute the effectiveness, so always buy repellent and sunscreen separately.

A 20% preparation provides several hours of protection; some products specify around six hours, while others advertise longer protection according to their formulation. Use the duration stated on your bottle as a guide, and, as with DEET, reapply after swimming, washing or heavy sweating in accordance with the instructions. Reapply if mosquitoes begin landing on treated skin, keeping within the product’s application limits.

PMD And Oil Of Lemon Eucalyptus

If you prefer a plant-derived mosquito repellent, PMD is an effective option supported by UK travel health guidance. It provides several hours of protection, although it generally needs more frequent reapplication than DEET.

PMD stands for p-menthane-3,8-diol. It is the chemical compound that actively repels mosquitos and occurs naturally in Oil of Lemon Eucalyptus, or can be synthesised artificially. Either way it is a plant based extract that is effective.

Oil of Lemon Eucalyptus is a refined plant extract taken from the lemon eucalyptus tree that is an effective repellent because it naturally contains high levels of PMD.

You may see the repellent ingredient listed as ‘Eucalyptus citriodora oil, hydrated, cyclized’, or encounter formulated products described as containing oil of lemon eucalyptus. These are processed repellent ingredients containing PMD, rather than simply eucalyptus oil added for its scent.

This is where you have to be careful because the similar sounding names cause a lot of confusion and the homeopathy market relies on this. A tested oil-of-lemon-eucalyptus repellent is not interchangeable with lemon eucalyptus essential oil or any other homemade mixture or product that merely smells of lemon. Those names can sound reassuringly similar while describing very different products. Look for the recognised active ingredient of PMD, its concentration and clear mosquito-repellent instructions.

A product containing 30% oil of lemon eucalyptus does not necessarily contain 30% PMD. The amount of PMD depends on the ingredient’s composition, so compare the declared active ingredients and the product’s tested protection time rather than treating the two figures as equivalent.

PMD gives travellers a genuine plant-derived alternative, so no matter whether you get the pure PMD or an Oil of Lemon Eucalyptus, look for 30% OLE or 30% PMD. that should give you around 6 to 8 hours protection, but should be reapplied regularly. Follow its application instructions and renew protection after swimming, washing or heavy sweating, keeping within the stated limits. Avoid contact with the eyes, because these products can cause eye injury.

IR3535

IR3535 is another clinically tested alternative to DEET recognised in UK travel health guidance. Its ingredient name may appear as ‘ethyl butylacetylaminopropionate’ or ‘3-ethlyaminopropionate’, so recognising the shorter name can make labels easier to navigate.

It is an established, effective repellent, but protection against malaria-transmitting mosquitoes can last less time than with DEET. Typically around 4 to 8 hours at its highest concentration. That makes it particularly important to keep the product accessible and reapply when needed, rather than assume one application will last throughout a long day outdoors.

Choose the highest-strength preparation available, as recommended by UK guidance, and check the protection time and application limits on the bottle. Swimming, washing and heavy sweating can shorten protection. Apply carefully around the face, keeping it away from the eyes.

IR3535 is a reasonable option if you prefer it to DEET or icaridin. The practical question is whether its application schedule fits your trip and whether you will comfortably maintain that protection.

What About Citronella, Essential Oils And Homemade Repellents?

There is no shortage of advice promising that you can keep mosquitoes away with citronella, a few drops of essential oil or something knocked together in a hostel kitchen. These suggestions often mix a little scientific truth with a considerable leap of faith.

Some plant oils do have mosquito-repelling properties. Citronella, for example, can repel mosquitoes, but its protection is short-lived. That is a very different proposition from providing reliable protection throughout an evening outdoors, particularly somewhere mosquitoes can transmit disease.

The same problem applies to many essential oil blends. An ingredient showing some repellent activity does not establish that a homemade mixture contains enough of it, distributes it evenly across your skin or protects you for a useful length of time. Adding more oil is no guarantee of better protection either, and may increase the risk of irritation.

Lemon water takes the wishful thinking a step further. A lemon scent does not give a spray the properties of a formulated PMD-based repellent. Lemon eucalyptus, lemon juice and whatever citrus-scented concoction someone recommends online are not interchangeable.

Homeopathic remedies have no reliable evidence supporting their use as mosquito repellents. There is no reason to rely on them to prevent bites, however enthusiastically someone insists they worked on their last trip.

Personal recommendations can be particularly misleading here. Someone might use a homemade spray and escape without a bite, but that does not establish why. Mosquito numbers, accommodation, clothing and how much time they spent exposed all affect their experience. ‘It worked for me’ cannot tell you how well a product will protect you.

If you prefer a plant-derived repellent, you already have an effective option in properly formulated PMD-based products. There is no need to gamble your protection on a recipe that mainly promises to make you smell nice.

Are Natural Mosquito Repellents Safer?

One of the biggest selling points of natural mosquito repellents is the suggestion that they are gentler, healthier or safer than DEET. It is an appealing message, particularly when you are choosing something to put on your skin every day. But there is no good reason to assume that a repellent is safer simply because its ingredients came from a plant, and there is even less reason to assume that non natural repellents are unsafe, because they aren’t.

DEET has decades of widespread use and extensive safety research behind it. Studies show a low risk of adverse effects when it is applied correctly, which is why it remains the first-choice repellent for travellers. That does not mean it is impossible for some individuals to react to it, some people are allergic to plasters, or deodorant, but the idea that using DEET normally means exposing yourself to dangerous levels of a toxic chemical is not true.

Properly formulated plant-derived repellents containing PMD, like Oil of Lemon Eucalyptus, also have a good safety profile when used as directed. They offer a legitimate choice for travellers who prefer them, but being plant-derived does not make them harmless. But if used incorrectly, like DEET repellents, PMD-based products can cause harm, and plant-derived products can cause allergic skin reactions too.

The truth is both chemical and plant based, or natural products are absolutely and provably safe. Both can cause harm if used incorrectly and there is always a chance, no matter how small any given individual may be allergic or react to it. If a repellent causes irritation or a rash, wash it off and stop using it. There are effective alternatives available; you do not need to put up with a reaction to protect yourself from bites.

The same reassurance cannot be extended to the products people generally associate with being ‘natural’ because they don’t contain ‘chemicals’. So called repellents that are homeopathic, homemade mixtures or cheap bottles of essential oil have as much chance of causing harm if used incorrectly, and have just as much chance of causing a reaction. Sure, most of the time half of it is nothing more than lemon scented water, which is unlikely to be effective, but just as unlikely to do much to your skin. The key thing is that you just don’t know. Ordinary lemon eucalyptus essential oil, for example, has not undergone the same validated testing for safety and effectiveness as established repellent products. Coming from the same plant does not make it an equivalent substitute.

So if anything, I’d go with the products that have the established effectiveness and proven safety record. Not the plethora of untested ‘natural’ products out there.

For your trip, the sensible choice is a repellent with evidence behind both its safety and its effectiveness. A properly formulated PMD-based product can meet that requirement, as can DEET and the other established alternatives. Choosing something less effective because the label sounds reassuring can leave you with less protection, particularly where mosquitoes carry disease.

Which Mosquito Repellent Should You Choose For Your Trip?

For most travellers, a repellent containing 50% DEET is a sensible first choice. It offers reliable protection, has an extensive safety record and is particularly useful when travelling somewhere mosquitoes can transmit malaria, dengue or other diseases. There is no reason to avoid it simply because it is a chemical repellent.

If you dislike DEET or cannot tolerate a particular product, 20% icaridin is a good alternative. Properly formulated PMD-based repellents and IR3535 are effective options too, although they generally require more frequent application. If choosing a plant-derived product matters to you, look for an established PMD-based repellent rather than relying on the word ‘natural’ across the bottle.

Whichever you choose, buy enough for your trip and use it consistently. Apply it evenly to exposed skin, follow the application instructions and remember that swimming, sweating and rubbing it off can shorten its protection. Advertised protection times are not a guarantee that one application will survive a sweaty afternoon exploring temples.

Repellent also works best alongside other precautions, including covering exposed skin and using screened accommodation or an appropriate mosquito net where needed. It does not replace antimalarial medication when that is recommended for your destination.

You have good options in both the natural and chemical camps. Choose one with an established active ingredient, a strong safety record and instructions you can realistically follow. Then get on with enjoying your trip, knowing you have taken a straightforward, worthwhile precaution.