On the back of the box, the very pricey ($40 for a 3.3 ounce bottle) Shiseido WetForce Ultimate Sun Protection Lotion SPF50+ makes the following promise: “Providing powerful protection for your skin, this innovative protective veil actually becomes even more effective when it comes into contact with water.” The claim on Shiseido’s website goes further, saying that soaking in water for 30 minutes enhances the product’s ultraviolet (UV) protection by 20 percent.
If you're going to be swimming or sweating, you want a good-performing water-resistant sunscreen, so we decided to investigate this claim by testing WetForce’s SPF (sun protection factor) in a laboratory. SPF is a measure of how well a sunscreen protects against UVB rays—the type that cause sunburn. First, our experts applied the sunscreen to dry skin on one area of our test subjects’ backs, let it dry, and then exposed that section to laboratory UVB light. Then we applied the sunscreen to a different area, let it dry, and had the subjects sit in a tub of water for 30 minutes. When they got out, we put that second area under the same UVB light. The next day, our experts examined both areas for sunburn.
We also subjected WetForce to the standard testing we perform on all sunscreens—measuring its UVB protection after the amount of time the product claims to be water resistant (in this case it was 80 minutes) and testing for protection against UVA rays, the type that cause wrinkles and skin cancer. (See our video on how we test sunscreens.)
What we found: The average SPF of Shiseido WetForce Ultimate Sun Protection Lotion SPF50+ was the same whether the testers’ skin was dry or exposed to water for 30 minutes. There was no increase in UVB protection.
In our standard sunscreen testing, WetForce did earn an Excellent rating for UVB (meaning it protects very well against sunburn), but just a Fair rating for its UVA protection. Combining the scores from our UVA and UVB testing with other performance factors, Shiseido WetForce Ultimate Sun Protection Lotion SPF50+ received a score of 40, which earned it a Fair rating for overall performance. (Our top rating is Excellent, followed by Very Good, Good, Fair, and Poor.)
We sent Shiseido a copy of our test results and methodology and asked the company for a response. Shiseido said in an e-mail: “It is our policy not to comment on testing done outside of the auspices of our company.” They also said that our findings may vary from theirs because of differences in test protocols.
Our bottom line: Given that our tests showed no improvement in UVB protection, Shiseido’s better-when-wet claim is misleading—and even potentially harmful if consumers interpret the claim to mean they don’t need to reapply the sunscreen when they get out of the water. At $40 for a 3.3 ounce bottle, Shiseido WetForce Ultimate Sun Protection Lotion SPF50+ is one of the most expensive sunscreens we’ve tested. We think that’s a high price to pay for a sunscreen that earned only a Fair rating overall in our tests, especially since we found several products that cost far less and performed better. For example, Coppertone Water Babies SPF 50 costs $10.50 for an 8-ounce bottle and received an Excellent rating for UVA and UVB protection. But whatever sunscreen you choose, be sure to reapply as soon as you get out of the water—or every two hours you’re out in the sun.
Consumer Reports has no relationship with any advertisers on this website. Copyright © 2006-2015 Consumers Union of U.S.