Sunscreen Formats Compared: Stick, Gel, Cushion or Lotion?

The format does not change the SPF number printed next to it, because that number is measured at a fixed dose: 2 mg of product per square centimetre of skin, the same amount for a stick, a lotion or a spray. What the format changes is how close you get to that dose. In the only study we located that measured all three formats in the same group of people, 52 participants applied lotion at a geometric mean of 1.1 mg/cm², spray at 1.6 mg/cm², and stick at 0.35 mg/cm² (Novick et al., Photodermatology, Photoimmunology & Photomedicine, 2015). That is the whole shopping decision: buy the format you will actually apply enough of, and read SPF and PA as dose-dependent test results rather than as promises about your day.

Korea's Ministry of Food and Drug Safety states the test dose plainly in its consumer guidance: apply "2 mg per 1 cm² of skin," evenly, 15 minutes before going out (MFDS, via the Korean government policy briefing, 5 June 2026). Almost nobody does. A literature review of sunscreen use found that "sunscreen under natural conditions is applied insufficiently with amounts about 0.39 to 1.0 mg/cm²," and concluded that "current sunscreen labelling overrates the protective effect of a given sunscreen when the reality of sunscreen use is taken into account" (Petersen & Wulf, Photodermatology, Photoimmunology & Photomedicine, 2014).

This is a category guide, not a product test. Glow Seoul Skin has performed no wear trials, no clinical evaluation and no hands-on comparison of any product or format described below. Every factual claim is attributed to a regulator, a standards body, a medical association or peer-reviewed literature. Nothing is asserted on our own authority.

The label number is a dose measurement, not a format rating

An SPF value is the output of a controlled human test. The international reference method is ISO 24444, Cosmetics — Sun protection test methods — In vivo determination of the sun protection factor (SPF) (ISO). It is tightly specified: JCIA's notification on the 2019 revision records that "sample application procedures have been described in greater detail by the product type," and that the beam uniformity of the solar simulator must be greater than or equal to 90% (JCIA). The standard, in other words, already knows that formats apply differently, and it removes that variable before it measures anything. Korea treats sunscreen as a functional cosmetic and requires the effect to be recognised by MFDS before the claim can appear, which is why MFDS tells shoppers to check for the 기능성화장품 mark on the package (MFDS).

Two consequences follow, and they are the reason format matters more than most front panels admit.

First, the number is anchored to a dose you are unlikely to reach. When application amount was varied in vivo, the relationship between amount applied and SPF delivered followed exponential growth (r² = 0.903): at 1 mg/cm² the SPF fell as the square root of the labelled value, at 0.5 mg/cm² as the fourth root, and at 4 mg/cm² it approached the square (Faurschou & Wulf, British Journal of Dermatology, 2007). That study used a single SPF 4 product on 20 volunteers, so treat the exponents as the shape of the relationship rather than a conversion table for an SPF 50 label. Even as a shape, it is decisive: under-application does not cost you a proportional slice of protection, it costs you a root.

Second, the test says nothing about the delivery mechanism. A stick, a cushion and a lotion carrying identical filter systems can all read SPF 50+ PA++++ while behaving completely differently in a bathroom at 7 a.m. The test controls the variable that your habits actually decide.

How to read SPF: what the number does and does not promise

SPF is an index of protection against the ultraviolet B that reddens skin. It is not a clock and not a percentage of your day. The American Academy of Dermatology puts the ceiling of usefulness bluntly: a sunscreen with SPF 30 "blocks 97% of the sun's UVB rays," higher SPFs offer minimal additional protection, and "high-number SPFs last the same amount of time as low-number SPFs" (AAD).

Two labelling conventions are worth knowing before you compare two Korean tubes.

The 50+ ceiling is a labelling rule, not a formulation limit. MFDS explains that above SPF 50 the real difference in protection is not large, while a bigger number invites shoppers to assume complete protection, so products are labelled "SPF 50+," which "means it provides sun protection of SPF 50 or higher" (MFDS). The Japan Cosmetic Industry Association writes the same rule as a statistical threshold: an SPF of 50 or above "shall be expressed as SPF 50+ if the lower limit of the 95% confidence interval is 51.0 or above, and as SPF 50 if the lower limit is less than 51.0" (JCIA Standards for SPF, PA and Water Resistance). Two products both reading 50+ are not thereby equal, and neither is bounded above by 50.

A high SPF does not buy time. In the United States, the drug labelling regulation for sunscreens requires the directions to say "Apply liberally and evenly 15 minutes before sun exposure," to reapply "at least every 2 hours," to reapply after the tested 40 or 80 minutes of swimming or sweating, and to reapply "immediately after towel drying." It also prohibits the words "waterproof," "sweatproof" and "sunblock" as unsupported claims (21 CFR 201.327). MFDS gives the same two-hour instruction for prolonged exposure and says it applies even to products carrying the stronger Korean water-resistance claim (MFDS).

How to read PA: the UVA scale used in Korea and Japan

SPF covers UVB. The plus signs cover UVA, and they are a separate measurement on a separate scale. The system originated with the Japan Cosmetic Industry Association, whose voluntary standards are, in JCIA's own words, "acknowledged as de facto standards by regulatory authority in Japan." Korea uses the same four-grade PA scale, which MFDS describes as running PA+, PA++, PA+++ and PA++++ (MFDS).

The grades are cut points on a measured UVA protection factor, determined in vivo by ISO 24442. JCIA's table is exact:

Source: JCIA Measurement Standards for UVA Protection Efficacy (2012 revised edition).

Three practical readings come out of that table.

PA++++ is an open-ended top grade. It means the measured UVA protection factor was 16 or above. It does not mean 16, and two PA++++ products can sit far apart inside the same grade. The same is true in reverse at the bottom: PA+ spans a measured factor of 2 up to just under 4, a doubling inside one plus sign.

The grades are coarse by design. Each step is a doubling of the underlying factor. Moving from PA++ to PA+++ is a bigger jump than the visual difference between two and three plus signs suggests.

The reading is a pigment-darkening endpoint, not a sunburn endpoint. The older Japanese index, PFA, was read as skin darkening occurring 2 to 4 hours after UVA exposure; under the ISO agreement, UVAPF "indicates skin darkening occurring 2 to 24 hours after UVA exposure" (JCIA). That is why UVA protection is discussed in terms of pigmentation and photoageing rather than sunburn, and why a shopper worried about pigment should read the plus signs first and the SPF second.

One more label rule is useful when you are comparing an unfamiliar product: PA cannot legally stand alone. Because no sunscreen protects against UVA only, JCIA requires that "when indicating the above UVA protection efficacy on a product it shall be necessary also to indicate the SPF value" (JCIA). A product showing plus signs with no SPF beside them is not following the convention the plus signs came from.

Formats ranked by how much product actually reaches skin

Only three formats have a published, directly comparable application-rate measurement that we could locate. Those three are ranked first, on data. The rest are ranked below them on what their construction and published usage instructions imply, and that distinction is stated openly for each one, because a guide that ranks six formats on three formats' worth of evidence is not a guide.

1. Lotion and cream, the reference format

Lotion is the format the whole SPF apparatus was built around, and it is the one you can see. In the Novick study, lotion landed at a geometric mean of 1.1 mg/cm², roughly half the tested dose but the most predictable of the three measured (Novick et al., 2015). It is also the format with a published, checkable quantity target: AAD says most adults need about 1 ounce, "roughly the amount to fill a shot glass," to cover skin not covered by clothing, and for the face "at least 1 teaspoon (about the amount needed to cover the length of your index and middle fingers)" (AAD).

Being able to measure the dose is the advantage. AAD notes creams are best for dry skin and for applying on the face (AAD). The disadvantages are the ones you already know: two hands, a wait, and a finish you may not want at lunchtime.

2. Spray, high measured volume, unverified evenness

The counterintuitive result in the Novick data is that spray produced the highest geometric mean of the three, 1.6 mg/cm² (Novick et al., 2015). Read that carefully: the study measured how much product was applied, not how evenly it was distributed. A format can deliver volume and still leave gaps.

The published usage instructions exist precisely because of that gap risk. AAD directs users to hold the nozzle close to the skin and "spray generously" until the skin glistens, then "rub it in thoroughly," to avoid spray sunscreen on windy days, and never to spray around or near the face or mouth. Spray onto the hands first, then apply to the face. It also warns against inhaling spray sunscreen and against using it near heat or open flame (AAD). A spray used as a quick pass without rubbing in is not the product that was tested.

3. Stick, the largest measured gap

Stick came in at a geometric mean of 0.35 mg/cm², roughly a sixth of the tested dose and about a third of what the same people managed with lotion (Novick et al., 2015). No other format difference in this guide is that large or that well measured.

That does not make sticks useless; it makes them a format with an application technique that has to be followed. AAD's instruction is specific: "For each area of skin you're protecting, apply four passes back and forth," then "rub it in afterwards for an even layer of coverage." AAD also identifies sticks as good to use around the eyes (AAD), which is a real advantage: a controlled solid is easier to place on an eyelid margin than a runny lotion. Buy a stick for precision and for carrying, not for covering a face fast.

4. Gel, a texture answer to a specific complaint

Gel is where the evidence thins out. AAD's format guidance is a suitability statement, not a dose statement: gels "are good for oily complexions and hairy areas, such as the scalp or male chest" (AAD). That is a genuine and often decisive reason to choose one: a lotion that will not spread through hair is a lotion that will not protect a scalp.

What does not appear to exist in the published literature, at least as far as this guide could source it, is any measurement of how much gel sunscreen people actually apply, so gel cannot be placed on the same scale as the three formats above. Treat gel as a format that removes a barrier to using enough product, and use the visible-quantity discipline from the lotion section to check that you did.

5. Cushion and compact, portability with no published dose data

A cushion is a delivery mechanism: a saturated sponge in a compact, dabbed on with an applicator. It has an obvious practical appeal for reapplication, and it is a genuine part of the Korean sunscreen shelf.

It is also the format with the least verifiable information behind it. No standards body treats "cushion" as a defined product form; Korea's cosmetics enforcement rule classifies basic skincare products by names like 로션, 크림, 에센스, 오일, 팩 and 마스크, and format words like "cushion" are trade descriptions sitting on top of that classification (Korean cosmetics law, 화장품의 개념 및 유형). We located no published study measuring how much sunscreen a cushion applicator deposits per press, and no test method for what a cushion delivers on top of existing makeup. If a cushion's SPF 50+ PA++++ is the same tested claim as any other product's, it was earned the same way: at 2 mg/cm², on clean skin, in a laboratory.

What you can check for yourself is the ingredient list, which Korean law requires on the package for every ingredient used (화장품법 제10조), and whether the product carries the MFDS 기능성화장품 mark (MFDS).

6. Essence-type and serum-type, a texture claim, not a category

"Essence sunscreen," "serum sunscreen" and "watery sunscreen" describe how a product feels. 에센스 is a named product type in Korea's cosmetics classification, but the classification assigns product types, not textures or protection mechanisms (Korean cosmetics law), and nothing in the SPF or PA test method changes because a formula is thin.

A thin, fast-absorbing sunscreen can be the right buy for exactly one reason, and it is a good one: if a heavy texture is why you skip sunscreen on weekdays, the texture is the problem worth solving. Just carry the lotion discipline over with it. A thin product spreads further per pump, which makes it easier to spread a visually satisfying layer that is well under 2 mg/cm². No published application-rate data for essence-type sunscreens could be sourced for this guide.

The comparison table a shopper can act on

Reapplication over makeup: the honest answer

Every SPF and PA number on every product in this guide was measured on bare skin, at a controlled dose, spread by a standardised technique (ISO 24444; JCIA). We located no standard test method, from ISO, JCIA, MFDS or FDA, that measures what any format delivers when applied on top of foundation, powder or a layer of sunscreen already worn for four hours. The label number does not describe that situation, in any format.

What the sources do support is narrower and still useful:

• The reapplication instruction is unconditional. Reapply at least every two hours outdoors, and immediately after towel drying (21 CFR 201.327). MFDS gives the same two-hour instruction for extended water activity even for products carrying the stronger Korean water-resistance claim (MFDS).
• A format that is easy to reach for is worth something on its own, because the reapplication that happens beats the one that does not. That is a behavioural argument for sticks, cushions and compacts, not a protection claim about them.
• Formats with published technique instructions (four passes and rubbing in for sticks, generous spraying and rubbing in for sprays) (AAD), cannot be shortcut over makeup without giving up the technique the guidance depends on.
• If the choice is between a rushed reapplication and none, the sources do not tell you the rushed one reaches the labelled SPF. They tell you protection scales steeply with dose (Faurschou & Wulf, 2007). Shade, a brim and sleeves are not consolation prizes here; they are the part of the plan that does not depend on your application technique.

Water resistance is a third claim, separate from SPF and PA

Water resistance is tested and labelled separately, and the two systems a Korean shopper is likely to meet do not use the same words.

In the United States, the label must state the tested interval: "Water Resistant (40 minutes)" or "Water Resistant (80 minutes)," with matching reapplication directions, and "waterproof" and "sweatproof" are prohibited (21 CFR 201.327).

Korea uses two claim tiers rather than a stated minute count. MFDS advises that for beach and pool use, where water and sweat remove sunscreen easily, you should choose a 내수성 (water-resistant) or 지속내수성 (very water-resistant) product, and that even a 지속내수성 product must be reapplied every two hours during long water activity (MFDS). JCIA maintains a separate standard for measurement of water resistance for UV protection, distinct from its SPF and PA standards (JCIA).

Formats do not inherit water resistance from their texture. A gel is not water-resistant because it feels light, and a stick is not water-resistant because it feels waxy. If the claim is not printed, it was not substantiated.

The four-line pre-purchase check

1. Read the plus signs, then the SPF. If pigmentation and photoageing are your reason for buying, PA is the UVA measurement and the grades double at each step (JCIA). PA with no SPF beside it is a label not following its own convention.
2. Ask what dose this format will let you apply. Choose the one you will use enough of. The measured spread between formats is real and large (Novick et al., 2015).
3. Check for the water-resistance claim in words, not vibes. A stated interval or a stated Korean tier, or neither (21 CFR 201.327; MFDS).
4. Confirm the functional-cosmetic recognition and read the ingredient list. MFDS recognition is what stands behind the UV claim, and Korean law requires every ingredient used to be listed on the package (MFDS; 화장품법 제10조).

FAQ

Is a sunscreen stick as good as a lotion?

For covering a face or body quickly, the measured evidence says no. In a 52-participant study, stick sunscreen was applied at a geometric mean of 0.35 mg/cm² against 1.1 mg/cm² for lotion, with the tested dose behind every SPF label being 2 mg/cm² (Novick et al., 2015). A stick is a good buy for targeted areas: AAD identifies sticks as useful around the eyes, and it needs its own technique: four back-and-forth passes per area, then rub in (AAD).

What does PA++++ actually mean?

It means the product's measured UVA protection factor was 16 or higher when tested by the in vivo method in ISO 24442. The full scale is UVAPF 2 to under 4 for PA+, 4 to under 8 for PA++, 8 to under 16 for PA+++, and 16 or more for PA++++ (JCIA). Because the top grade is open-ended, two PA++++ products are not necessarily equivalent.

Why do Korean sunscreens all say SPF 50+ instead of a higher number?

Because the label is capped. MFDS explains that differences above SPF 50 are not large in practice while a bigger number encourages shoppers to assume total protection, so anything at or above that level is written "SPF 50+," meaning SPF 50 or higher (MFDS). JCIA states the same rule as a statistical test on the 95% confidence interval (JCIA).

Does a spray sunscreen count as a real application?

It can, if used the way the guidance describes. Spray produced the highest measured application amount of the three formats studied, 1.6 mg/cm² (Novick et al., 2015), but that study measured quantity, not evenness. AAD directs users to spray generously until the skin glistens and then rub in thoroughly, to avoid windy days, and never to spray near the face; spray onto the hands and apply to the face instead (AAD).

Can I reapply sunscreen over makeup and keep the SPF on the label?

The label number cannot answer that. SPF and PA are measured on bare skin at 2 mg/cm² under standardised methods (ISO 24444; JCIA), and we located no standard test that measures delivery over makeup for any format. The reapplication instruction itself is unconditional, at least every two hours outdoors, and immediately after towel drying (21 CFR 201.327), so the practical move is to choose a format you will actually reach for and to lean on shade and clothing for the part your technique cannot guarantee.

Which sunscreen format is best for oily skin or a scalp?

AAD's format guidance points to gel: gels are "good for oily complexions and hairy areas, such as the scalp or male chest," while creams are best for dry skin and for the face (AAD). No published measurement of how much gel sunscreen people apply in practice could be sourced, so treat gel as the format that removes an obstacle to using enough, then check the amount by eye against the teaspoon-for-the-face benchmark rather than trusting the texture.