What changes immediately, and what takes longer?

WhenWhat to expect
After applicationSunscreen forms a protective layer. Some formulas leave visible white residue.
During sun exposureCorrectly applied sunscreen reduces exposure to UV radiation and helps prevent sunburn.
With continued useSun protection helps prevent premature wrinkles and age spots caused by repeated UV exposure.
If skin already has sun damageProtection remains worthwhile because it reduces further damage and the risk of sun induced skin cancer.
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Tinted sunscreen containing iron oxide also helps protect against visible light, which can worsen dark spots, particularly in darker skin tones.1

What are the benefits of sunscreen?

Sunscreen protects against ultraviolet radiation, or UV: sunlight that contributes to skin aging and skin cancer. UVA reaches deeper into skin and contributes to tanning, uneven pigmentation and premature aging. UVB is the main cause of sunburn. Broad spectrum protection covers both types, while SPF mainly describes protection against UVB.2

SPF 30 provides about 97% protection against UVB, compared with about 98% for SPF 50 or higher, when applied at the amount used in testing. Applying too little reduces the protection you receive. No sunscreen blocks all UV radiation, so use clothing and shade alongside sunscreen rather than relying on the bottle alone.14

How to apply sunscreen

  1. 1Choose a broad spectrum, water resistant sunscreen with SPF 30 or higher.
  2. 2Apply sunscreen to dry skin 15 minutes before going outdoors, every day you will be outside.
  3. 3Use at least 1 teaspoon for your face. Most adults need about 1 ounce to cover all exposed skin, with more needed depending on body size.
  4. 4Cover your ears, neck, tops of your feet and exposed scalp as well.
  5. 5Reapply approximately every two hours outdoors, and after swimming or sweating, following the bottle's directions.
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Does lotion go before or after sunscreen?

Moisturizing lotion goes before sunscreen in your morning skincare routine. Finish skincare with sunscreen rather than adding moisturizer over it. For sensitive skin, mineral sunscreens containing zinc oxide or titanium dioxide are a recommended option.15

What if you already have sun damage?

Years of sun exposure can leave more wrinkles, uneven darker and lighter patches, and rough areas, especially on the face, neck, forearms and hands. Starting sun protection still reduces the risk of new lumps and bumps and sun induced skin cancer. Examine sun damaged skin every few months. See a doctor for a spot that grows and does not heal, or a lump that becomes painful, bleeds, develops an open sore or thickens.3

After acne scar treatment, sunlight can darken treated skin. Apply sunscreen daily to that area and follow your dermatologist's specific aftercare instructions. Skin generally needs protection from prolonged daytime sun exposure for 6 to 8 weeks after treatment. Improvements in depressed scars come from treatment and the time needed to make collagen and elastin, not simply from applying sunscreen.6

What does skin look like before and after a Korean skincare routine?

A Korean skincare routine emphasizes hydration, gentle care and a more even skin tone, with sunscreen as the final morning step. Ten steps are not required for a Korean skincare routine, even if the numbered version is excellent at giving every bottle a job. Introduce products slowly so you can identify what helps and what causes a reaction. If you have sensitive skin, test new products on your inner arm before using them on your face. Treat the routine as a way to care for skin, not a fixed before and after result.5

Where this answer comes from

  1. 1Sunscreen FAQsaad.org
  2. 2Sunscreens: A Complete Overviewdermnetnz.org
  3. 3Care for skin with sun damage and after treatment for a skin cancer or pre-cancercuh.nhs.uk
  4. 4Sunscreens: A Complete Overviewdermnetnz.org
  5. 5Steps to a Korean Skin Care Routinehealth.clevelandclinic.org
  6. 6Acne scars: How to care for your skin after treatmentaad.org