How to Apply Sunscreen
When to Apply Sunscreen
The vast majority of medical experts and scientists agree: Sunscreen is always, always, the final step in your daytime skincare routine. Any skincare product applied over a sunscreen dilutes the sunscreen's effectiveness to some degree. It’s that simple. This is the way sunscreens are tested to obtain their SPF number, so you must follow suit to get the needed protection rather than compromise your skin.
Do you also need a moisturizer to wear under your sunscreen? The answer is probably not. Many facial sunscreens have sophisticated anti-aging, hydrating formulas along with the sunscreen, so you shouldn’t need a second product as long as it’s rated SPF 30.
For an extra skin-rejuvenating boost, you can always apply an antioxidant-rich serum before your sunscreen. Antioxidants help to shield skin from environmental assault that slowly chips away at its youthful appearance, and they work brilliantly with (or in) sunscreens.
How Much Sunscreen to Apply
The common direction is to apply sunscreen "liberally," but what does "liberal application" really mean? For an average-size person, a liberal application of SPF might look like ½ teaspoon (about a nickel-sized portion) for the face, plus one ounce (a standard-sized shot glass full) for the rest of the body.
With that said, it’s very important to keep in mind that because some individuals have a larger face or a bigger frame, you’ll need to take your size plus the actual amount of exposed skin into consideration. There are all kinds of mathematical formulas for this, but generally we’d just say "put a lot on." Apply a layer you can see, and then massage it into the skin and wait until what you can still feel on the skin absorbs. How much sunscreen to apply depends on how much skin you need to protect.
To further illustrate this application issue, if you’re wearing a bikini and you have a bigger frame, one ounce is not going to be enough. If you’re wearing sun protective clothing and only have limited parts of your body exposed to the sun, you will need less than an ounce. However, don't count on your thin, summery street clothes to protect you during long days outside. Look to special sunscreen clothing companies such as the Sun Precautions and Coolibar brands. Both companies sell clothing specially tested and rated to provide protection from daylight, even after the garment is laundered dozens of times.
When Can You Go Outside After Applying Sunscreen?
Without a shred of doubt, you must apply sunscreen before you leave the house. Waiting until you get to where you’re going exposes your skin to an incredible amount of damage well before you arrive. What might be really shocking to you (it was to us) is that research shows sun damage begins the first minute your unprotected skin sees daylight!
As a general rule, it’s best to apply sunscreen between 15 and 30 minutes before you go outside. However, equally important is to let it absorb in before you get dressed. Research has shown that if you get dressed immediately after applying sunscreen, a lot comes off on your clothing. That’s not good because for sunscreen to do its job, it needs to be on your skin, not on your clothes.
We know this one is difficult to follow because time is of the essence when you’re trying to get out of the house, but do the best you can. If you can wait at least 15 minutes before you get dressed that would be best. Or apply sunscreen over the exposed areas of skin after you get dressed and then wait 15 to 30 minutes before going outside.
Do You Need to Reapply Sunscreen Every Two Hours?
This is a complicated topic. We wish it wasn’t, and it certainly wasn’t our doing, but hang in there and we will try to explain what you need to know about this absolutely essential skincare step.
The recommendation by most medical experts and regulatory boards you’ve probably heard or read is to reapply sunscreen every two hours. This is a separate recommendation from the need to reapply water-resistant sunscreens after swimming or sweating, which we’ll explain in a moment. For now, we’re just talking about using regular sunscreens and moisturizers with SPF not designed to be used when swimming or sweating.
The SPF rating still tells you how long you can be in the sun without having your skin turn pink, an obvious sign of damage. But the issue of reapplication is about being outside in direct sunlight. If you apply sunscreen in the morning and spend most of your day inside, 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. So, on an average day, your morning application of sunscreen is still going to provide some sun protection on your way home.
But, and this is a big but, this assumes you’ve applied a liberal application in the morning! The "reapply every two hours" recommendation is based primarily on the fact that most people don’t apply sunscreen liberally. By reapplying sunscreen every two hours, you will get liberal application resulting in better and longer sun protection. But if you’re good about a liberal application from the start, this recommendation might not pertain to you.
Water-resistant sunscreens (not waterproof as there’s no such thing as a waterproof sunscreen, all of them come off in a relatively short time in water or from sweating) have an entirely different set of rules when it comes to reapplication. These rules for reapplication are non-negotiable; the protection will be gone if you’re not diligent and methodical about reapplying water-resistant sunscreen accordingly.
Water-resistant sunscreens have two different time limits for reapplication that should be stated clearly on the label (if it isn’t, don’t use it for swimming or if you will be excessively perspiring). Some water-resistant sunscreens will be labeled as being effective for 40 minutes, while others will be labeled as being water-resistant for 80 minutes. It is imperative you know how much time you have before you need to reapply a water-resistant sunscreen when you’re swimming or sweating profusely.
One additional sun protection tip: To prevent signs of aging on your hands, you must reapply sunscreen after washing your hands as soap and water will significantly remove even a liberal application or water-resistant sunscreen. It’s a good idea to keep a small container of sunscreen with you at all times.
Do I need Sunscreen if I’m Inside All Day?
Most likely yes, because the UVA rays of daylight present year-round come through windows. This is an incredibly important fact for you to know. Even if you’re inside your home or office or driving in your car, you will not be protected from this type of UV light if you’re not wearing sunscreen.
If your car, home, or office have windows with UV filters then that’s great, but that won’t protect you during your walk to the car or bus and your walk to the office or that quick lunch break. Remember, sun damage begins within the first minute unprotected skin sees daylight.
Applying Makeup Over Sunscreen
What about applying foundation (one that doesn't contain sunscreen) over the sunscreen you've just applied? Will this dilute the sunscreen you’ve just applied? If you follow these guidelines your face will remain well protected.
- Wait 3–5 minutes for the sunscreen to set before applying foundation.
- Make sure you apply foundation in smooth, downward motions.
- Do not use a rubbing or back-and-forth motion.
- Do not use excess pressure and do not over-blend.
If you are not the sort to wait, opt for a foundation/tinted moisturizer with SPF 30 or greater and then you can apply it liberally too and get an even a better layer of protection.
If your foundation or tinted moisturizer has sunscreen, that’s a fine way to get protection for your face but you must wear it liberally. If you’re not someone who likes that much coverage from their foundation or a heavy application of a tinted moisturizer, then don’t rely on these product as your only source of facial sun protection.
For the same reason, do not rely on pressed or loose powders that contain sunscreen for your sole SPF protection, as most people do not apply powders liberally enough to get the amount of protection stated on the label (and with good reason, as doing so requires a lot of powder)!
Although powders are an iffy way to get sun protection for the face, they are a great way to touch up your makeup during the day and reapply more sunscreen at the same time. If you prefer loose powders, look for those that come with a built-in brush, as these are less messy and easy to use while on the go—but ultimately a pressed powder is most convenient and tidy.
The Best Skin of Your Life Starts Here: The same type of in-depth scientific research used to create this article is also used to formulate Paula’s Choice Skincare products. You’ll find products for all skin types and a range of concerns, from acne and sensitive skin to wrinkles, pores, and sun damage. With Paula’s Choice Skincare, you can get (and keep) the best skin of your life! See Paula's Choice Sun Protection Products.
References for this information:
Science, February 2015, issue 6224, pages 842-847
Photodermatology, Photoimmunology, and Photomedicine, April-June 2014, issue 2-3, pages 96-101
Annals of Internal Medicine, June 2013, issue 11, pages 781-790
Cutis, December 2012, issue 6, pages 321-326.
Clinical Experimental Dermatology, December 2012, issue 3, pages 904-908
Journal of the American Academy of Dermatology, February 2010, issue 2, pages 218-222
British Journal of Dermatology, February 2010, issue 2, pages 415-419
Photochemistry and Photobiology, April 2003, issue 4, pages 453-457