Korean Sunscreen 101: Chemical vs Physical SPF, and What to Buy

Reading SPF and PA ratings on Korean sunscreens

Korean sunscreens use both an SPF rating (protection against UVB, the rays primarily responsible for burning) and a separate PA rating with up to four plus signs (PA++++ being the highest), which measures UVA protection specifically -- UVA rays are more associated with long-term skin aging and pigmentation than sunburn. Looking for both a high SPF and PA++++ gives more complete protection than focusing on SPF number alone, which is a common gap in sunscreen shopping.

Chemical vs physical formulas

Chemical sunscreens absorb UV rays and convert them to heat, typically feeling lighter and more cosmetically elegant under makeup, while physical (mineral) sunscreens, built around zinc oxide or titanium dioxide, sit on top of the skin and physically deflect UV rays, generally considered gentler for sensitive or compromised skin. Korean chemical sunscreen formulas are often praised specifically for feeling lighter than Western equivalents, though physical formulas remain the more cautious choice for sensitive or recently treated skin.

Considerations after any skin treatment

• Freshly treated skin (post-laser, post-peel, post-needling) is generally more sun-sensitive and more prone to pigmentation issues if unprotected.
• A fragrance-free, physical sunscreen is the more conservative choice while skin is actively healing.
• Reapply more frequently than the bottle suggests if you're outdoors sightseeing for extended periods, regardless of formula type.
• Ask your provider directly if a specific brand or type is recommended following your particular treatment.

Application amount matters just as much as formula type -- most people apply meaningfully less sunscreen than the tested amount used to determine a product's rated SPF, so reapplying more generously and more often than feels intuitive is a simple way to get closer to a sunscreen's actual labeled protection.