In this article:
Why sunscreen is so important
When to apply sunscreen in your skin care routine
Which goes first: sunscreen or moisturiser?
When to apply sunscreen
How much sunscreen to apply
How much sunscreen to use on face?
When to reapply sunscreen
How to reapply sunscreen over makeup
Do I need to wear sunscreen indoors?
It seems simple, right? Apply sunscreen to exposed skin before you go outside, and you’re done. But it isn’t that simple: The when, where, and how you apply sunscreen is important, but often confusing.
We’ve examined all the latest research and have definitive answers to your most burning sunscreen questions. Get ready to keep your skin protected and looking younger, longer!
Why sunscreen is so important
Nothing is as critical for keeping skin younger-looking, protected and resilient as daily use of a broad-spectrum sunscreen. This is something Paula’s Choice Skincare has embraced with every sunscreen we've created.
If your skin is exposed to daylight, even indirectly (in the shade of a tree or when you’re in your car), it needs sunscreen. This means that yes, you should wear sunscreen every day, even when you’re indoors, as UV light can penetrate windows!
When used as directed with other sun protection measures, sunscreen decreases the risk of UV-caused skin issues and early skin ageing caused by the sun (1,2).
When to apply sunscreen in your skin care routine
Most medical experts, regulatory boards, and scientists agree: Sunscreen is always the final step in your daytime skin care routine. This is exactly how sunscreens are tested to earn their SPF rating. Any skin care product you apply over sunscreen dilutes and reduces its effectiveness.
What about the products you apply before your sunscreen? Just follow your normal skin care routine (cleanser, toner, exfoliant, etc.) and consider adding an antioxidant serum. Research has shown that antioxidants help further shield skin from daily environmental stressors that slowly chip away at its youthful appearance.
Which goes first: sunscreen or moisturiser?
If you’re using a sunscreen and a separate moisturiser, apply the moisturiser first, followed by the sunscreen as your final skin care step. But do you really need a moisturiser under your sunscreen? Probably not. Today’s best daytime moisturisers with SPF combine hydration and beneficial skin care ingredients, in addition to broad-spectrum sun protection. You shouldn’t need two products if the formula you’ve chosen is suitable for your skin type and skin concerns.
When to apply sunscreen
Apply sunscreen 15 to 30 minutes before you go outside and be sure you let it absorb before you get dressed. If you get dressed immediately after applying sunscreen, it can rub off on your clothing where it won’t be of much help to your skin.
We repeat: You must apply sunscreen before you go outside. Waiting until you’re outdoors exposes your skin to an incredible amount of damage. Research has shown that sun damage begins the first minute your unprotected skin sees daylight—not sunlight, but daylight – and continues for hours after you’ve gotten out of the sun, making it critical to avoid it altogether (3).
One last note on when to apply: We’re often asked if applying foundation that doesn’t contain SPF over the sunscreen you’ve just applied will diminish the sunscreen’s ability to protect skin. It won’t if you follow these guidelines:
- Wait 3–5 minutes for the sunscreen to set before applying foundation.
- Apply the foundation in smooth, downward swiping motions. Rubbing back and forth can cause pilling and upset the SPF underneath.
- Do not use excess pressure or over-blend.
- It's even better when your foundation, BB cream or tinted moisturiser contains sunscreen too— we love to layer sunscreen! It's best to match mineral SPF makeup with mineral sunscreens and synthetic SPF makeup with synthetic sunscreens.
How much sunscreen to apply
The common direction is to apply sunscreen “liberally,” but what does “liberal application” really mean? You’ll find measurement recommendations (one to two teaspoons for your face, a shot glass full for your body), but they don’t really make sense. Why? Because not everyone has the same size body or face and not everyone has the same amount of skin exposed to daylight. Compliance is also an issue—studies have shown that people tend to underapply sunscreen by 20-50% of the recommended value (4) .
How much sunscreen to use on face?
To be sure you’re applying enough sunscreen on your face:
- Spread a visible layer over the areas of your skin that will be exposed to daylight, including the ears, neck, etc (5).
- Massage this layer into the skin.
- If you’re planning a long day outside, apply another slightly thinner layer (6).
The same advice applies to the body.
When to reapply sunscreen
One of the more confusing issues about sunscreen use is seeing label instructions to reapply every two hours. To make it more perplexing, this is about regular face or body sunscreens—not water-resistant sunscreens, which have their own timeline for reapplication. With water-resistant sunscreens, you must follow the specific reapplication instructions for adequate protection after getting wet or perspiring.
For daily use of regular facial moisturisers with sunscreen, the question is how can you reapply every two hours if you’re wearing makeup? Are you supposed to wash your face, reapply sunscreen, and then reapply your makeup only to do it all again in another two hours?
The two-hour recommendation came about because the research made it clear most people were not applying sunscreen liberally. Therefore, regulators followed the logic that if a person applies sunscreen again two hours later, they’d be ensuring more adequate protection. BUT if you apply it liberally in the beginning, reapplication isn’t critical.
Plus, the issue of reapplication is about being outside in direct light without seeking shade. If you apply sunscreen in the morning and spend most of your day inside (without your skin getting wet or perspiring heavily) and if when outside, you’re seeking shade, wearing sunglasses and hats with brims, your sunscreen should still be effective by the end of the day. This is because sunscreen actives break down in response to direct exposure to daylight, not just from the passage of time.
We know, it’s complicated. As wonderful as the sun feels and despite the good moods it inspires, we can’t change the fact that it's harmful to skin and causes premature and progressive ageing (7). Figuring all this out isn’t easy, but for the sake of your skin, at the very least:
- Apply sunscreen liberally to all exposed skin 365 days a year.
- On long days outside wear higher SPF-rated products.
- You can also layer sunscreen products, especially for the face, by wearing a moisturiser with SPF + a foundation with SPF and touch up with an SPF-rated powder.
- You must wear water-resistant sunscreens when swimming or perspiring and follow the reapplication directions exactly.
- Reapply sunscreen to your hands after washing (keeps them looking young too).
- Seek shade, wear UV-rated sunglasses and wide-brimmed hats.
- Wear sun-protective clothing whenever possible (it’s less expensive than applying sunscreen liberally all over an entire body in the long run).
How to reapply makeup over sunscreen
That leads us to the next question many people have for us - is there a way to reapply or refresh your SPF after you've applied makeup?
In this case, setting or blotting powders with SPF can be a quick and easy way to add sun protection throughout the day. But we have to point out that you shouldn’t rely on pressed or loose powders with sunscreen as your only sun protection, because the amount required for this application generally ends up looking cakey or chalky.
If you use a liquid or cream foundation with SPF, you can do a spot reapplication using a sponge. Take care just to dab the foundation where you need extra sun protection; don’t rub or blend excessively, as that will disrupt the makeup you’ve already applied.
If you don’t like the idea of applying more foundation, try reapplying your sunscreen the same way—dabbed on carefully, with a sponge—essentially pressing it in to skin instead of rubbing. Of course, not all sunscreen formulas will lend themselves to this type of application, so experiment to see if this might be an option for you.
Do I need to wear sunscreen indoors?
Yes, you should wear sunscreen indoors. The UVA rays of daylight that are present year-round come through windows. If you think that just walking to your car and then into a store or office won’t damage your skin, think again; those few minutes of UV light exposure add up over the years, causing your skin to age faster than you want.
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References for this information:
- Cosmetics, July 2019, pages 1-13
- Annals of Internal Medicine, June 2013, pages 781-790
- Science, February 2015, pages 842-847
- American Academy of Dermatology, Website, Accessed January 2025
- Photodermatology, Photoimmunology, and Photomedicine, April-June 2014, pages 96-101
- Clinical Experimental Dermatology, December 2012, pages 904-908
- Life, April 2021, pages 1-14
