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We all know how important it is to slather on sunscreen before heading outdoors, but did you know that it's equally—if not more—crucial to apply SPF even when you're indoors? Or that you really should be reapplying about every two hours?
Because the hard and fast rules of UV protection are often blurred, we've reached out to dermatologists to find the truth behind sunscreen: when to wear it, how much to apply, and for how long.
- Ava Shamban, MD, is a board-certified dermatologist in Los Angeles.
- Elizabeth Tanzi, MD, is a board-certified dermatologist and associate clinical professor at George Washington University Medical Center in Washington DC.
- Debra Jaliman, MD, is a board-certified dermatologist in New York City.
- Carmen Castilla, MD, is a board-certified dermatologist in New York City.
- Amanda Lam is a cosmetic chemist.
- Heidi B. Prather, MD, is a board-certified dermatologist in Austin,Texas
- David Colbert, MD, is a board-certified dermatologist in New York City.
- Joshua Zeichner, MD, is a board-certified dermatologist and director of cosmetic and clinical research at Mount Sinai Hospital in New York City.
- Amy B. Wechsler, MD, is a board-certified dermatologist in New York City.
- Mona Gohara, MD, is a board-certified dermatologist in Hamden, Connecticut.
Myth: You don’t have to wear sunscreen indoors. While this seems to make sense, experts say you should still wear sunscreen inside. Even when you spend most of your day indoors, "UV exposure can occur from ultraviolet that penetrates through glass, which is UVA,” says Ava Shamban, a board-certified dermatologist in Los Angeles. “UVA is emitted at the same level all day long whereas UVB, which is blocked by glass, peaks midday."
No amount of time spent outdoors is too small to consider wearing SPF either. "Many of us discount the sun that we get on a daily basis from just running errands and all the incidental sun damage adds up," explains Elizabeth Tanzi, MD, a board-certified dermatologist and associate clinical professor at George Washington University Medical Center in Washington, DC. "That's why we recommend daily sunscreen application, so you are always protected and don't have to think about it."
Sunscreen should be worn all over the face, ears included, recommends New York City-based, board-certified dermatologist Debra Jaliman, MD. "Cover your entire face with sunscreen as well as your neck and hands," she says. "You can apply it first thing in the morning."
If you don’t have much hair, the FDA recommends applying sunscreen to your head as well. And when wearing hairstyles that expose the scalp, like box braids or a sleek bun with a part, opt for a hair mist, oil, or powder with SPF like the Coola Scalp and Hair Sunscreen with SPF 30, which has a spray nozzle for easy application before styling.
Carmen Castilla, MD, a board-certified dermatologist in New York City, suggests following the "two-finger" rule for your face and neck: Dispense sunscreen along the length of your pointer and middle fingers. This amount will ensure that your face and neck are protected. "There really is no harm in applying extra sunscreen, so if you are unsure you are adequately protected, just apply some more," says Dr. Castilla. If you’re worried about looking greasy, try the Supergoop! Mineral MatteScreen SPF 40. The oil-free formula and matte finish make it especially great for oily skin.
Unfortunately, the two-finger rule doesn't apply to foundations or skin tints formulated with SPF. "If the makeup claims a SPF value (and has a drug fact label) then it is a sunscreen, it has gone through the testing and regulatory guidelines to categorize it as such," says cosmetic chemist Amanda Lam.
Complexion products are "often applied too thin," so they "only provide a fraction of the labeled SPF," says Heidi B. Prather, a board-certified dermatologist in Austin, Texas. In other words, in pursuit of a more seamless finish, you might be buffing away the protection.
Dr. Gohara echoes this, saying, "You need to wear an extra layer of sunscreen when wearing makeup with SPF, even if they have UV filters."
"The American Academy of Dermatology always recommends an SPF of 30 because it is clinically proven to be a sufficient amount of protection to reduce or minimize the adverse effects of sunlight," says David Colbert, MD, a New York City-based, board-certified dermatologist.
Joshua Zeichner, MD, the director of cosmetic and clinical research in dermatology at Mount Sinai Hospital in New York City, adds that when used properly there's little difference between a sunscreen with SPF 30 and something with higher protection.
"However, in the real world we do not apply as much sunscreen as we should and we do not reapply," Dr. Zeichner says. “This ultimately means that the SPF value is diluted out. Starting with a higher SPF serves as a safety net to ensure the highest quality of protection for the longest period of time.”
Spending the day poolside? Dr. Castilla says that the recommended amount of sunscreen for someone in a swimsuit is one ounce, which is about one shot glass full.
"Ideally, sunscreen should be reapplied every two hours or more frequently if you are swimming or sweating heavily," says Dr. Zeichner. "The best time to apply sunscreen is before you go outside because there are [fewer] distractions and you can make sure that you have adequately covered all exposed areas."
Blame it on the controversial ingredient list of chemical sunscreens (and how they could be harming the world's coral reefs), but dermatologists all seem to agree that mineral sunscreen is your best bet for protection.
"I really like mineral sunscreen formulas with zinc and titanium because they're natural ingredients," says Dr. Tanzi. "These physical sunscreens sit on the surface of the skin to deflect the rays." And mineral formulas are better suited for sensitive types as they don't irritate the skin. We love the 2019 Allure Best of Beauty Award winner, The Unsun Mineral Tinted Sunscreen SPF 30 because it doesn't leave a white cast, making it a winner for all skin tones. La Roche-Posay Anthelios 50 Tinted Mineral Ultra-Light Fluid Sunscreen, a 2023 Allure Best of Beauty winner, is also a great pick as it blends mineral blockers and tinted spheres into one tone-perfecting, skin-softening fluid.
Sun protection doesn't just involve applying sunscreen. "Be sure to wear sun-protective clothing, a hat, and sunglasses," says New York City board-certified dermatologist Amy B. Wechsler, MD. "I know I sound like a maniac, but UV exposure is the number one cause of premature aging [and] skin cancer."
"People forget to protect their lips and skin cancer in this area can be particularly dangerous," says Dr. Tanzi. "Everyone needs lip balm with SPF." Our pick? The Supergoop Play Lip Balm SPF 30 with Acai, is packed with moisturizing shea butter and nourishing vitamin E. Dermatologist-loved brand Aquaphor recently launched its lip balm with SPF 30. The small packaging makes it convenient to bring everywhere.
Though you probably never considered it, your eyelids need protection too. “The skin [around the eyes] is more fragile and thinner, making it more susceptible to fine lines and photoaging, so sunscreen is essential,” says Dr. Gohara. You don’t need a special sunscreen for this area. You just need to remember to give it a more targeted SPF. Dr. Gohara recommends using a sunscreen stick. We love the EltaMD UV Stick Sunscreen because the fragrance-free stick is infused with zinc oxide to provide broad-spectrum SPF protection and is compact enough for on-the-go, mess-free application.
All products featured on Allure are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.
More on sun protection:
- 11 Sun Protection Tips From the Country's Best Dermatologists
- Everything You Wanted to Know About Skin Checks (But Were Afraid to Ask the Internet)
- SPF You Can Eat
Now, follow these tips for safe tanning:
