What is SPF?

Sun damage isn't only about burning. UV exposure is the largest external contributor to premature skin aging, and it's the reason dark marks deepen and keep returning after you think you've treated them.

Most of that exposure is incidental. Walking to your car. Sitting by a window. Ten minutes outside at lunch. It accumulates quietly across years, which is exactly why daily use beats occasional heavy use.

SPF also protects the work the rest of your routine is doing. If you're using Vitamin C to brighten, or actively treating pigmentation, skipping sunscreen undoes that progress faster than the actives can build it. It's the difference between treating your skin and treating your skin while continuing to damage it.

SPF stands for Sun Protection Factor. It measures how well a sunscreen protects against UVB rays, the ones responsible for burning.

The number describes filtration, not time. SPF 30 filters roughly 97% of UVB. SPF 50 filters around 98%. The gap between them is far smaller than the numbers suggest, which is why how much you apply and how often you reapply matters more than reaching for a higher factor.

The most common misreading of the label is that SPF 30 lets you stay out thirty times longer. It doesn't. Those lab-tested numbers assume an application thickness almost nobody achieves in real life, so the protection you actually get from SPF 50 applied thinly can be lower than SPF 30 applied properly.

The American Academy of Dermatology recommends a minimum of SPF 30, broad spectrum, applied daily. Higher is fine. Lower isn't really worth the bottle.

Not sure which factor you need? Read SPF 30 vs SPF 50: Which Should You Actually Use?

SPF only tells you about UVB. UVA rays don't usually burn, but they penetrate deeper into the skin and are the ones most associated with premature aging and pigmentation. They also pass straight through cloud cover and window glass, which is why grey days and desk jobs still count.

In the US, sunscreen is regulated by the FDA as an over-the-counter drug, not a cosmetic. That's why labels look the way they do, with a Drug Facts panel on the back listing active ingredients and their percentages.

The phrase you're looking for is broad spectrum. It's an FDA-regulated term, and a product can only use it if it passes a specific test proving meaningful UVA protection alongside its SPF rating. If a bottle gives you a number but doesn't say broad spectrum anywhere, you're only getting half the picture.

Two other things worth knowing about US labels:

Water resistance is stated in minutes. You'll see either 40 minutes or 80 minutes. No sunscreen sold in the US can legally be called waterproof or sweatproof, because none of them are. Those two numbers tell you how long the stated SPF holds up while swimming or sweating, after which you reapply.

Percentages are listed for every active. If you want to know exactly how much zinc oxide you're getting, it's on the back, which is genuinely useful for comparing products.

Mineral filters, zinc oxide and titanium dioxide, sit on the surface of the skin and reflect and scatter UV. They tend to suit reactive or sensitive skin, and they're effective from the moment they're applied. The tradeoff is texture. Mineral formulas can feel heavier and are more likely to leave a white cast, particularly on deeper skin tones, though modern formulations have improved considerably.

Chemical filters absorb into the uppermost layer of skin, convert UV into heat, and release it. They're usually lighter, sit better under makeup, and rarely leave a cast. The tradeoff is that they can sting sensitive eyes and some people find they don't suit reactive skin.

One thing worth flagging for US shoppers specifically: the FDA approves a narrower list of filters than Europe, Japan or Korea do. If you've read about newer filters like Tinosorb or Uvinul and can't find them here, that's why. The filters available in the US are effective, but the menu is shorter, which is part of why texture complaints are more common in the US market.

Neither type is better. It comes down to what your skin tolerates and what you'll genuinely wear every day, because the best sunscreen is the one you don't skip.

Want the full breakdown? Read Mineral vs Chemical Sunscreen

Dry skin does better with a formula that has hydration built in, so it doesn't cling to flaky patches or emphasize texture. Applying over a well-hydrated base helps more than the sunscreen itself. More in Sunscreen for Dry Skin

Oily or blemish-prone skin suits lightweight, non-greasy textures that won't add shine through the day. Look for fluid or gel formats rather than rich creams. More in Sunscreen for Oily, Blemish-Prone Skin

Sensitive skin often prefers mineral filters and shorter ingredient lists, and tends to react less to fragrance-free options. More in Sunscreen for Sensitive Skin

Pigmentation-prone skin needs daily SPF without exception. UV is the primary driver that makes dark marks deepen and return, so sunscreen isn't a supporting step here, it's the main treatment. More in SPF for Hyperpigmentation

Deeper skin tones burn less easily but are far from exempt. Pigmentation and uneven tone are the more common concerns, and both are driven by UV. If white cast has put you off in the past, chemical or hybrid formulas are usually the better route.

Not sure of your type? Take a look at What's Your Skin Type?

Sunscreen isn't a replacement for a serum or a moisturizer. It goes on top of both.

A serum treats a specific concern. A moisturizer holds hydration in place. SPF protects everything you've just applied.

The order that works: cleanse, serum, moisturizer, SPF. Serum first because it's the lightest texture and needs direct contact with skin. Moisturizer next to seal that hydration in. SPF last, because filters are formulated to sit on or near the surface, and burying them under a heavy cream compromises how well they perform.

If your skin runs oily or you're layering under makeup, Omega Water Cream at $15 is oil-free and sits cleanly under sunscreen. If you're drier, Bio-Active Ceramide Moisturizer at $22 gives you more cushion and helps sunscreen spread evenly rather than dragging.

For an extra layer of hydration underneath, Hyaluronic Acid Serum at $13 applied to slightly damp skin gives sunscreen a smoother base to sit on. This matters more than people expect. Most complaints about how sunscreen feels are really complaints about what's underneath it.

Most people apply somewhere between a quarter and half of the amount sunscreens are tested with, which means the real-world protection is meaningfully lower than the number on the bottle.

For your face and neck, roughly two fingers' length, squeezed along your index and middle fingers. Alternatively, about a quarter-sized amount.

For your body, about one ounce, which is roughly a shot glass, to cover exposed skin.

The spots people consistently miss: ears, hairline and part line, the sides and back of the neck, the backs of the hands, and eyelids. These are the areas that show sun exposure earliest, and they're the ones that get skipped most.

If applying that much feels like too much at once, apply in two thinner passes a minute or so apart. You'll get closer to the right amount without the heaviness.

Every two hours when you're outdoors, and immediately after swimming, sweating heavily, or towel drying, regardless of the water resistance number on the bottle.

If you're indoors and away from windows for most of the day, your morning application will generally hold. You don't need to reapply at your desk simply because two hours have passed.

Reapplying over makeup is the part everyone finds difficult. Powder and mist SPF formats exist for exactly this reason, and while they're harder to apply at the correct thickness, using something is meaningfully better than using nothing.

For the practical detail, read How to Reapply Sunscreen

Pilling is when sunscreen rolls into small balls instead of absorbing. It's almost always a layering issue rather than a bad product.

The three usual causes are applying onto skin that's still wet with serum, using too much product in a single pass, or rubbing it in rather than pressing.

What helps:

• Give each layer around thirty seconds to settle before the next one
• Press SPF in with your fingertips rather than rubbing it around
• Use less per pass and go over your face twice
• Watch for interactions between silicone-heavy and water-based products, which is a common culprit

If a particular combination pills every single time, it's the combination, not your technique. Swap one of the two products rather than fighting it.

SPF goes on after skincare and before primer or base. Give it two or three minutes to settle before anything goes on top, which is the single biggest fix for makeup that won't sit properly.

Don't try to get your SPF from foundation alone. Most makeup with SPF in it is applied far too thinly to deliver the protection stated on the packaging, so treat it as a bonus rather than your actual sunscreen.

If your base clings to dry patches through the day, HydroSurge Dewy Face Mist at $14 helps without disturbing the SPF underneath.

Yes, and this is one of the most common reasons people are getting less protection than they think.

The FDA requires sunscreens to maintain their stated strength for three years, so if there's no expiration date printed on the bottle, three years from purchase is your marker. Many products do print a date, and some include an open jar symbol indicating how many months it lasts once opened, usually twelve.

UV filters degrade over time. An old bottle simply won't protect the way a fresh one does, even if it looks fine. If the texture has separated, the color has changed, or it smells different from when you bought it, replace it.

Heat accelerates all of this. A bottle that's spent a summer in a car or on a sunny windowsill has aged faster than the date suggests. Store sunscreen somewhere cool and out of direct light, and if you're at the beach, keep it in the shade or a bag rather than out on the sand.

One useful rule: if you're using the right amount, a bottle shouldn't last you three years anyway. An expired sunscreen is usually a sign of under-application.

Tinted sunscreens contain pigments, typically iron oxides, which add light coverage and provide some protection against visible light. That last part matters. Visible light, including from screens and indoor lighting, can worsen melasma and certain forms of pigmentation, and standard UV filters don't block it. Iron oxides do.

If you're actively treating melasma or persistent pigmentation, a tinted formula is worth considering for that reason alone rather than for the coverage.

Untinted suits anyone who wants sunscreen to disappear under makeup, doesn't want to match a shade, or is sharing a bottle across different skin tones.

We don't sell sunscreen in the US, tinted or otherwise, so there's nothing for us to steer you toward here. Whichever you choose, apply the same amount. Tinted formulas can look like they're doing more because you can see them, which sometimes leads people to use less.

For pigmentation specifically, SPF for Hyperpigmentation and our Hyperpigmentation guide go deeper.

UV exposure in the US varies enormously depending on where you live, which makes blanket seasonal advice close to useless.

Southern states like Florida, Texas, Arizona and Southern California see high UV essentially year-round. There's no off-season.

Northern states see a genuine winter dip in UVB, but UVA stays present all year, and it's UVA that drives aging and pigmentation.

Altitude changes the math. UV intensity rises roughly 10% for every 1,000 meters of elevation, so a winter day in Denver or a ski trip can deliver more UV than a summer day at sea level.

Snow and water reflect. Fresh snow bounces back up to 80% of UV, which is why skiers burn under their chin. Water and sand reflect too, meaning shade under an umbrella is not full protection.

The practical version: wear it daily regardless of season or forecast. If you want a rule, check the UV index in your weather app and treat 3 or above as non-negotiable. In much of the US, that's most of the year.

Full detail in Do I Need to Wear SPF All Year Round?

Faces get all the attention, but hands, chest, neck and ears often show sun exposure earlier, and they're harder to treat after the fact.

The same rules apply. Be generous, reapply every two hours outdoors, and don't skip cloudy days. Pay particular attention to the back of the neck, the tops of the feet, and the part in your hair.

If you're exfoliating your body, SPF matters more, not less. Freshly exfoliated skin is more sun sensitive, so daily protection on those areas isn't optional.

Sunscreen is formulated to stay put. That's the entire point, and it's also why a splash of water and your regular cleanser won't fully remove it. Left on overnight, it can sit in pores and contribute to congestion, which is where the idea that sunscreen causes breakouts largely comes from.

Start with an oil-based first cleanse to break the filters down, then follow with your usual cleanser. With Oat Cleansing Balm at $17, your makeup and SPF don't stand a chance.

This step matters more the more sunscreen you're using correctly. If you've increased your application amount after reading this guide, upgrade your evening cleanse at the same time.

More in How to Remove Sunscreen Properly and The Complete Guide to Double Cleansing

Vitamin C and SPF belong together in the morning. Antioxidants help defend against free radical damage that sunscreen alone doesn't address, while SPF protects the brightening work your Vitamin C is doing. Neither replaces the other. Read Vitamin C and SPF: Why You Always Need Both

Retinol works the other way. It's a nighttime active, and it increases sun sensitivity, which makes daily SPF non-negotiable while you're using it. Using retinol without sunscreen can leave your skin worse than when you started.

Exfoliating acids follow the same principle. AHAs in particular increase photosensitivity, so if you're exfoliating regularly, sunscreen is part of the treatment, not an optional extra.

Niacinamide pairs well with everything, including SPF, and is a useful addition if you're targeting tone and texture alongside sun protection.

More in our Vitamin C, Retinol and Niacinamide guides.

If you've had more sun than you intended, the priority is cooling and hydrating, not treating.

Keep skin cool, drink water, and skip anything active. Retinol, acids and strong vitamin C should all wait until skin has fully settled, usually several days.

Ectoin Hydro-Barrier Serum at $17 supports the skin barrier when skin feels stressed and compromised. HydroSurge Dewy Face Mist at $14 is useful for cooling, and keeping it in the refrigerator makes it more soothing.

If skin is blistering, or you have a fever, chills or nausea after sun exposure, that's a medical issue rather than a skincare one. See a doctor.

• Do I Need to Wear SPF All Year Round?
• SPF 30 vs SPF 50: Which Should You Actually Use?
• Mineral vs Chemical Sunscreen
• How to Reapply Sunscreen
• How to Remove Sunscreen Properly
• Sunscreen for Sensitive Skin
• Sunscreen for Oily, Blemish-Prone Skin
• Sunscreen for Dry Skin
• SPF for Hyperpigmentation
• Vitamin C and SPF: Why You Always Need Both

Explore More Guides

• Vitamin C 
• Retinol 
• Hyperpigmentation 
• Niacinamide 
• What's Your Skin Type? 
• The Complete Guide to Double Cleansing 
• Skincare Routine Guide