Sunscreen Or Mosquito Repellent: Which Goes On First?

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.

You’ve just started your gap year, and after a day or two acclimatizing you’ve landed on your first tropical island. The place is paradise, filled with white sand, a few beach huts on one end of the beach and a beach bar and restaurant down the other. It’s perfect. Except for one problem. The sun is blazing and the mosquitoes are already taking an unwelcome interest in your ankles. You need sunscreen and mosquito repellent, but standing there with a bottle in each hand raises a surprisingly common question. Which goes on first?

The simple answer is sunscreen first, followed by your mosquito repellent after it has dried. That’s the basic clinical guidance and the end of a very short article.

Fortunately, protecting yourself from sunburn and mosquito bites does not need to become a complicated skincare ritual. Getting the order right and knowing when to reapply will help you keep both working while you get on with enjoying your trip.

There are a few practical details worth knowing, though, especially if you are using DEET or spending the day swimming, sweating and topping up your sunscreen.

Which Goes On First: Sunscreen Or Mosquito Repellent?

Apply your sunscreen first, allow it to dry, then apply your mosquito repellent to exposed skin. That is the recommended order when using DEET alongside sunscreen. I’ve used DEET because that is the most common repellent, but it is the same advice for Icaridin or PMD based repellents.

Give each product its own application rather than mixing them together in your hands. That just creates a gooey mess and reduces the effectiveness of the DEET and the sunscreen. Apply sunscreen generously, following the instructions on the bottle, then apply enough repellent to evenly cover the skin that needs protection. Avoid your eyes and mouth, and do not apply repellent to cuts or irritated skin.

There is no need to set a stopwatch between the two unless your product instructions specify a waiting time. Letting the sunscreen dry before applying repellent is a straightforward routine to follow before heading out.

Does DEET Affect Your Sunscreen?

DEET can reduce the protection your sunscreen provides. That does not mean you have to choose between avoiding sunburn and avoiding mosquito bites: you can use both, with a little care.

Choose a sunscreen with SPF 30 to 50 and good UVA protection. That is the clinical guidance, although personally I never go below factor 50. Apply it generously before your DEET repellent, and keep up with reapplication throughout the day. Using a higher SPF does not mean you can apply less or leave it on longer.

You may see claims that DEET reduces sunscreen protection by a precise percentage, but the effect depends on the products and how they are used. It is more useful to concentrate on applying both properly than trying to calculate what SPF you have left.

Clothing and shade help too. A loose, long-sleeved shirt can spare you some sun exposure while also covering skin mosquitoes might otherwise bite. Sunscreen remains one part of sun protection, rather than permission to spend the whole afternoon baking.

What Happens When You Need To Reapply?

Sunscreen and mosquito repellent do not necessarily need topping up at the same time. Sunscreen should be reapplied at least every two hours while you are out in the sun, and after swimming, sweating or towel drying. Repellent needs reapplying according to its own instructions and the conditions you are using it in.

When you top up your sunscreen over DEET, you may disturb the repellent layer and shorten its protection. You can reapply repellent afterwards when needed, but stay within the product’s instructions, including any limit on the number of applications per day. Do not assume every sunscreen top-up requires another full application of repellent.

You do not need to scrub everything off and start again each time. Keep your sunscreen topped up, check whether your repellent needs refreshing and remember that the protection time advertised on the bottle may be shorter in hot, sweaty conditions.

If mosquitoes start landing on treated skin, take that as a prompt to check your protection. If you have reached your repellent’s application limit, use clothing, screens or a mosquito net as appropriate rather than repeatedly adding more.

What About Swimming And Sweating?

A swim, a sweaty walk or a good rub down with a towel can remove sunscreen and mosquito repellent. Neither should be assumed to last for its advertised protection time regardless of what you have been doing.

After swimming, dry your skin and reapply sunscreen, even if it is labelled water-resistant. Water-resistant does not mean waterproof, and towel drying can remove it too. Once the sunscreen has dried, reapply repellent if needed, following its instructions and application limits.

Heavy sweating can also shorten the protection of both products. If you have spent the morning hiking in tropical heat, check what needs topping up rather than assuming your first application will see you through until lunch.

Keep both somewhere accessible in your day bag. They are much easier to use when they are beside your water bottle than buried beneath three days of laundry back at the hostel.

Should You Buy Combined Sunscreen And Repellent?

Generally, no. A bottle offering both sun protection and mosquito protection sounds convenient, but separate products are the recommended choice.

Combined products can use ingredients such as icaridin or PMD rather than DEET, quite often in smaller quantities than is recommended, and combined products may be generally less effective overall.

The practical problem is that you cannot control the two applications separately. Sunscreen needs to be applied generously and topped up frequently, while the repellent has its own instructions, protection time and application limits. Applying a combined product sparingly to avoid overusing the repellent can leave you inadequately protected from the sun. Reapplying it every time you need more sunscreen may mean applying repellent more often than recommended.

Using separate products lets you maintain both forms of protection properly. Choose an appropriate sunscreen and an effective repellent, apply sunscreen first and follow each product’s instructions. Saving a little space in your wash bag is not worth making that routine harder.

A Simple Routine, Then Back To Your Trip

Using sunscreen and mosquito repellent together does not need to become a chore. Keep them in your day bag, apply sunscreen first and repellent afterwards, and top each up according to its instructions and what you have been doing.

You do not need to spend every waking moment worrying about bites or sunburn. A few sensible habits, alongside shade and suitable clothing, will give you worthwhile protection while leaving you free to enjoy the reason you packed those bottles in the first place: getting out there and exploring.