What can you compare?

FeatureSKIN1004 Sun SerumBeauty of Joseon Relief Sun
ProtectionChemical sunscreen labelled SPF50+ PA++++, with UVA and UVB protectionExact protection rating needs confirmation
Texture and finishLight, quickly absorbed cream with a serum texture and dewy finishTexture and finish need confirmation
FormulaIncludes niacinamide, centella extract and several forms of hyaluronic acidFull ingredient list needed for a formula comparison
DirectionsApply evenly to exposed areas as the last skincare stepExact application directions need confirmation
Price positionNo matched size and currency comparison establishedNo matched size and currency comparison established
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SKIN1004 describes a nonsticky, nongreasy finish with no white cast, but the intended finish is glowy rather than matte. The word serum describes the sunscreen's texture, not another compulsory department in your skincare routine.1

Which should you choose?

Choose SKIN1004 if its light, moisturizing texture and dewy finish match what you want. The brand lists normal, dry, combination and sensitive skin among its intended users. That sensitive skin positioning is not a reason to ignore a previous reaction to an ingredient.1

For sensitive skin, general dermatology guidance favors mineral sunscreens containing zinc oxide or titanium dioxide. If sensitivity drives your decision, include that option rather than treating these two names as the entire shortlist.2

The best sunscreen is one you will use repeatedly, with UVA and UVB protection, SPF30 or higher, and water resistance. Choose by those features and a finish you will wear, rather than which name has assembled the larger skincare vocabulary.2

Is Water Fit suitable for swimming?

Do not treat Water Fit in the product name as a water resistance rating. For swimming or sweaty exercise, choose a sunscreen explicitly labelled water resistant and follow its reapplication directions. Under US labelling rules, water resistant sunscreens specify 40 or 80 minutes of protection during swimming or sweating. No sunscreen is waterproof, and all eventually wash off.23

How should you apply sunscreen?

  1. 1Finish your basic skincare first. SKIN1004 directs you to apply its sunscreen last, evenly over areas exposed to UV rays.
  2. 2Apply sunscreen to dry skin 15 minutes before going outdoors. This timing is general sunscreen guidance.
  3. 3Use enough for full coverage. General guidance specifies at least 1 teaspoon for the face and about 1 ounce for an adult's exposed skin, with more needed depending on body size.
  4. 4Cover commonly missed areas, including your ears, neck, hairline, hands and tops of your feet. Avoid getting sunscreen in your eyes or mouth.
  5. 5Reapply approximately every two hours outdoors, and after swimming or sweating, following the bottle's directions.
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What does the protection rating tell you?

SPF primarily describes protection against UVB, the rays responsible for sunburn. UVA also contributes to skin aging and skin cancer, so check for protection against both. Neither a high SPF nor moisturizing ingredients replace sufficient application and reapplication.4

Use sunscreen on exposed skin when going outside, including in winter and cloudy weather. Add shade and clothing that covers exposed areas, because sunscreen alone does not block all ultraviolet radiation.256

Check the expiry date and keep your sunscreen away from extreme heat or cold. While outside, store the tube in shade rather than direct sun. If buying a version sold outside the US, read that product's label for differences in directions and labelling.35

Where this answer comes from

  1. 1Hyalu-Cica Water-Fit Sun Serumskin1004.com
  2. 2Sunscreen FAQsaad.org
  3. 3Sunscreen: How to Help Protect Your Skin from the Sunfda.gov
  4. 4Sunscreens: A Complete Overviewdermnetnz.org
  5. 5American Academy of Dermatology survey shows sun protection lacking in winteraad.org
  6. 6Sun Protectiondermnetnz.org