Does Korean Sunscreen Work Better?

The chart below compares the two products from each K-beauty brand—a U.S formula and a Korean formula. The Korean products provided significantly better protection than the U.S. formulas.

We also put the sunscreens through the same sensory evaluation that we use for all the sunscreens we test. Whether a particular sunscreen smells good or feels pleasant is somewhat subjective, but our panelists are trained to assess the products and describe them objectively. (The tests are blind, so our panelists’ conclusions are not influenced by any expectations based on labeling or brands.)  

We were surprised by the results of our sensory tests on these Korean sunscreens. “You often hear that Korean sunscreens are so lightweight and absorb so quickly that it’s like wearing nothing at all,” says Mely Llamas, who oversaw CR’s sunscreen sensory tests. “But that wasn’t our panel’s experience. Their feel and look on the skin were on a par with many of the other more cosmetically elegant facial sunscreens in our tests, but none stood out as being super lightweight or having a barely-there feel.”

We saw little difference between the brand pairings, and all six sunscreens performed similarly. They required a fair amount of effort to rub in and initially felt greasy and left a white cast. After 10 minutes, the sunscreens absorbed fairly well, but a slight greasy feeling remained. On the positive side, the panelists found all the products left skin feeling moisturized and gave it a dewy look.  

The main difference between Korean and U.S. sunscreen formulas lies in the ultraviolet (UV) filters that are used in the products. Sunscreens are designed to protect against two types of UV light. The sun protection factor (SPF) indicates how well a sunscreen protects the skin from UVB rays, which cause sunburn. A broad-spectrum sunscreen protects against both UVB and UVA rays, which are primarily responsible for premature skin aging. (Both contribute to skin cancer.) In CR’s tests, we measure both UVA and UVB performance. We also look at how closely the SPF listed on the product’s label matches a sunscreen’s average-tested SPF.

Sunscreen manufacturers in the U.S. have fewer UV filters to work with than companies in other countries. Until recently, the FDA had approved just 17 filters, and only a handful of them, such as avobenzone, homosalate, octisalate, octocrylene, zinc oxide, and titanium dioxide, are typically used. In June, the FDA approved the first new filter in more than 25 years, bemotrizinol. (This ingredient is one of several filters used in Innisfree’s Korean formula.)

The FDA regulates sunscreen as a drug, so getting FDA approval for new UV filters is a long and expensive process. In Korea and myriad other countries, sunscreens are regulated as cosmetics, and the approval process is more streamlined. The upshot is that overseas manufacturers can use a broader range of UV filters when formulating their products.

Korean sunscreens that contain filters that have not been approved by the FDA can’t be legally sold here. (That’s one reason the brands we tested developed different products for the U.S. market.) While individuals can purchase them from overseas websites—which is how we bought the Korean formulas for our testing—it comes with a risk: If your package is flagged at the border, it may be confiscated. According to the FDA’s Regulatory Procedures Manual, FDA personnel will decide on a case-by-case basis whether to allow or prohibit entry of personal shipments of drugs that “appear violative.”

CR uses a testing protocol that’s modeled on the one the FDA requires sunscreen manufacturers to use. But as is the case with other products we test that have government or industry standards, we use those standards as benchmarks and have developed our own methodology to identify differences in performance and give consumers a comparative evaluation.

For SPF, we test the sunscreens on three people, which is fewer than the FDA’s protocol calls for, but we use a statistical analysis to verify our results.

To check SPF in water-resistant sunscreens, a technician applies a standard amount of each sunscreen to a 2x3-inch rectangle on each panelist’s back. Then the panelists soak in a tub of water for 40 or 80 minutes, depending on the product’s water-resistance claim. (We perform the test after water immersion only for water-resistant sunscreens, because if a sunscreen holds up on wet skin, it should hold up on dry skin.) Afterward, smaller sections of the rectangle are exposed to five or six intensities of UV light from a sun simulator for a set time based on how quickly the panelist’s skin burns without protection. (We also use a reference sunscreen with known performance to ensure the accuracy of the testing.) About a day later, a trained technician examines the areas for redness and determines the SPF.

The testing for non-water-resistant sunscreens involves the same steps—applying the sunscreen, exposing the skin to UV light, and examining the skin the next day—except for water immersion.

For a sunscreen to be labeled broad-spectrum, the FDA requires that it protect against UVA and UVB rays. To test for UVA protection, we smear sunscreen onto plastic plates, pass UV light through them, and measure the amount of UVA and UVB radiation absorbed. That information is used to calculate our UVA score.

This process is similar to the critical-wavelength test that the FDA requires sunscreen manufacturers to perform to label their products as broad-spectrum. But we apply the results differently. The critical wavelength test is a pass/fail test, and just as you can pass a test with either an A or a D grade, some sunscreens do a much better job of defending against UVA than others. That’s why we use a method similar to that used in other countries, which allows us to measure the critical wavelength and the level of UVA protection a sunscreen provides.