Style Skincare Suncare 10 Sunscreen Mistakes Even Smart People Make Sunscreen can only do its job if you do yours. By Genevieve Monsma Genevieve Monsma Genevieve Monsma is a lifestyle writer and editor with over two decades of experience in print and digital publishing. Highlights: * Began her career as an associate beauty editor at Redbook * Two years as beauty director at CosmoGirl * Five years as deputy beauty editor at Marie Claire * One year as beauty director at Shape * Seven years as beauty director at MORE * Founder of beauty blog, MediumBlonde * Her work has appeared in Real Simple, InStyle, Shape, and ELLE, among other publications. Real Simple's Editorial Guidelines Updated on December 11, 2022 Fact checked by Emily Peterson Fact checked by Emily Peterson Emily Peterson is an experienced fact-checker and editor with Bachelor's degrees in English Literature and French. Our Fact-Checking Process Share Tweet Pin Email Considering the fact that 1 in 5 Americans will develop skin cancer in their lifetime, it's always a good time for a (proverbial) skin check. Although SPF seems like a relatively straightforward process, applying it incorrectly can leave you more exposed than you realize. Here, dermatologists sound off on the most common sunscreen missteps. Getty Images 01 of 10 You don't put on enough You've heard that one shot glass of sunscreen is enough to cover your body. Problem is, knowing and doing are two different things, says Marcy Street, MD, a board-certified dermatologist in Okemos, Mich. Studies show that most people apply just a quarter of the amount needed to reach the SPF on the bottle. "Under-applying an SPF 15 means that you're really getting an SPF 8," says Dr. Street. To ensure the right amount, measure a generous handful for your body and a nickel-size blob to protect your face. 02 of 10 You don't reapply frequently enough Every sunscreen must be reapplied. Period. No matter what the SPF—15 or 50—all formulas (water-resistant ones, too) degrade significantly after two hours in the sun, and sooner than that if you've been in water or sweated heavily. But reapplication isn't important only when you're lounging at the beach. "If you spend your day next to a window or driving around in a car, you are getting UV (ultraviolet) exposure through the glass," says Jeanine Downie, MD, a board-certified dermatologist in Montclair, N.J. She recommends using stick or powder sunscreens, such as Colorscience Sunforgettable Brush On Sunscreen SPF 50 ($69; dermstore.com), for everyday reapplication because they're easy to swipe over exposed areas and won't muss your makeup. Another good one: Neutrogena Ultra Sheer Face + Body Stick Sunscreen Broad Spectrum SPF 70 ($13; target.com). 03 of 10 You look only at SPF Don't see the words "broad spectrum" on your bottle? You're probably not getting protection from both UVB rays (which burn and cause cancer) and UVA rays (which penetrate more deeply, cause cancer, and accelerate skin aging). "Most sunscreens today are broad spectrum," says Dr. Downie. "But that's not always true with moisturizers or makeup with SPF, which often do not provide UVA protection. Think of these as extra credit, and wear a broad-spectrum sunscreen every day, year-round, as well." 04 of 10 You think all formulas are created equal The shot-glass analogy refers only to lotion. Sunscreen sticks, sprays, and wipes may make it more convenient to apply protection on the go, but they also increase your risk of under-application, because they go on so thinly. "Your goal is to have an obvious sheen everywhere you've put on sunscreen," says Andrew Alexis, the chairman of the department of dermatology at Mount Sinai St. Luke's and Mount Sinai West, in New York City. That means two—yes, two—generous coats of spray, neck to toe, in a shielded area. With wipes, apply two of them, rubbing the first over the body head to toe, then the second toe to head. Swipe sticks over areas three times. 05 of 10 You slather on too late Most chemical sunscreens "must be applied about 30 minutes before you go in the sun," says Steven Rotter, MD, a board-certified dermatologist in Vienna, Va., and a spokesperson for the Skin Cancer Foundation. "It takes that long for the ingredients to activate and start absorbing UV rays." In contrast, physical sunscreens, with ingredients such as titanium oxide and zinc oxide, work straight from the bottle, because they literally block UV rays like a stone wall, rather than absorbing them, so there is a minimal activation period. 06 of 10 You think having darker skin makes you immune "Someone with very dark skin may have a natural SPF of between 5 and 8," says Dr. Downie. However, while having that extra melanin can minimize a person's risk of burning, it does not protect her from UVA rays or the skin cancer they can cause, she warns. Additionally, because the skin is darker, "we don't have the obvious marker of a burn to tell us when we've sustained serious sun damage," says Alexis. "And later on it's not as easy to see skin cancer developing on dark skin because, while something like basal-cell carcinoma appears pearly pink on a Caucasian, on a deep skin tone, it's often a more subtle brown spot that tends to scab more easily." Finally, because skin cancer is harder to detect on dark skin, when it is diagnosed, the prognosis is often dire: Late-stage melanoma diagnoses are twice as high for Black and Native American patients than White patients. Bottom line: "All skin colors must wear sun protection daily, because everyone can get skin cancer from UV exposure," says Alexis. 07 of 10 You skip spots "Most of us are pretty diligent about applying sunscreen to the face, but then we forget the ears or the lips or the back of the neck," says Dr. Downie. So it's no coincidence that these three often-neglected spots are among the most frequent sites for basal-cell and squamous-cell carcinomas, the two most common non-melanoma skin cancers. Melanoma, meanwhile, crops up most frequently on the backs of women's legs, another area that is hard to see and reach. The moral: Coat all exposed areas with sunscreen and reapply regularly. 08 of 10 You don't take the risk seriously "We often hear patients say, 'It's "just" skin cancer,' when they get a diagnosis. They figure they'll get it removed and be done with it," says Shelby Moneer, the director of education for the Melanoma Research Foundation. "But it's important to know that melanoma can spread to distant organs, and that's how it takes people's lives. And it often spreads quickly." The latest statistics show that in the United States one person dies of melanoma every hour. But basal-cell and squamous-cell carcinomas can both metastasize as well. More than 5 million Americans are expected to be diagnosed with some form of skin cancer this year. That's why dermatologists stress the importance of annual skin checks and keeping tabs on your own skin. Don't wait until your checkup if you notice a new or suspicious spot; call your doctor. "We say, 'If you see something, say something,' " says Moneer. 09 of 10 You rely solely on sunscreen "Sunscreen is an important element of sun protection, but it shouldn't be the only one," says Alexis, who says that we must also avoid prolonged and intense sun exposure (like tanning) whenever possible and wear clothing and accessories to help block the sun. Darker-colored fabrics with a tight weave and fit offer the most UV protection. Certain clothes also provide an ultraviolet protection factor (or UPF), with most boasting a UPF of 50+, which means only 2 percent of the sun's rays can penetrate. Stylish sun-protection companies include Parasol, Cover, and Nike. 10 of 10 You hold on to a sunblock for too long The U.S. Food and Drug Administration mandates that sunscreens either retain their full strength for three years or include an expiration date. Check the bottle. If yours doesn't have one, write the purchase date on the tube. If you can't find a date and can't remember when you bought the product, toss it or call the manufacturer's customer-service number for more information. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit Sources Real Simple is committed to using high-quality, reputable sources, including peer-reviewed studies, to support the facts in our articles. Read our editorial guidelines to learn more about how we fact check our content for accuracy. American Academy of Dermatology, Skin cancer. Petersen B, Wulf HC. Application of sunscreen--theory and reality. Photodermatol Photoimmunol Photomed. 2014;30(2-3):96-101. doi:10.1111/phpp.12099 Dawes SM, Tsai S, Gittleman H, et al. Racial disparities in melanoma survival. J Am Acad Dermatol. 2016;75(5):983-991. doi:10.1016/j.jaad.2016.06.006 National Council on Skin Cancer Prevention. Skin Cancer Facts & Statistics. American Cancer Society. Basal & squamous cell skin cancers.