Many of us (myself included) slather on sunscreen daily, despite the season and/or the weather. And, if you don't, you definitely should . But, according to a new study, all that skin-care due diligence might not be as effective as we had hoped. Sigh.Over the past year, Consumer Reports researchers diligently tested out over 60 lotions, sprays, and sticks with claimed ratings of SPF 30 or higher. The findings uncovered that 28 (that's 43%) of the products tested allegedly had less SPF protection than their labels promised — and some even came in at an SPF rating of less than 15. Yes, we know, such great news to hear a month before summer.These findings are in addition to the sunscreen testing Consumer Reports has been doing over the past four years, which didn't fare much better. The worst offenders of the bunch were products claiming to be water-resistant (CR says they weren't), as well as mineral or "natural" sunscreens that contained chemical blocks as active ingredients. As the study points out, companies are required to test their products, but the catch is they're not required to submit those results unless the FDA requests them.CR is calling for stricter guidelines from the FDA, and cosmetic chemist Ni'Kita Wilson agrees that the testing methods should absolutely be more standardized. But, she also points out that there's more to these findings than meets the eye. Mainly, sunscreen companies don't all test their products in the exact same manner, which could have led to these shocking results."What [CR] fails to understand is that [these companies] may not have been testing the products under the same conditions," Wilson says. "In order to test for the SPF, the product is applied on the back, then slowly hit with UV light until the skin shows signs of redness. [Simply put], the longer it takes to turn red, the higher the SPF." She goes on to explain that if a brand were to irradiate the skin with very low energy, then it will obviously take longer to redden than if the testers used a higher energy. "Therein lies the problem: The FDA doesn't specify a specific energy level, so it can vary from testing lab to testing lab based on their standard practices," says Wilson.