We all know how important it is foam suncream before you step outside, but did you know it’s the same – if not more — important to apply SPF even when you are indoors? Or that you really should reapply every two hours or so?
Because the strict and fast rules of UV protection are often blurred, we turned to dermatologists to find out the truth behind sunscreen: when to wear it, how much to apply, and for how long.
Meet the experts:
- Elizabeth Tanzi, MD, is a board-certified dermatologist and associate clinical professor at George Washington University Hospital in Washington DC.
- Ava Shamban, MD, is a board-certified dermatologist based in Los Angeles.
- Debra Jaliman, MD, is a board-certified dermatologist based in New York City.
- David Colbert, MD, is a board-certified dermatologist based 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 based in New York City.
- Carmen Castilla, MD, is a board-certified dermatologist based in New York City.
1. Sunscreen should be worn daily, no matter where you are – indoors and outside.
“Fully indoor activities don’t require sun protection, but many of us reckon the sun we get daily just from running errands, and all of the ‘accidental’ sun damage adds up,” explains Elizabeth Tanzi, MD, a board-certified dermatologist and associate clinical Professor at George Washington University Medical Center. “That’s why we recommend daily sunscreen application so that you are always protected and don’t have to think about it.”
That means even if you spend most of your day indoors, says Ava Shamban, a board-certified dermatologist in Los Angeles, “UV exposure can come from ultraviolet penetrating glass, which is UVA. UVA is emitted at the same level all day long, while UVB, which is blocked by glass, peaks at midday.
2. For daily wear, sunscreen should be applied to the face and other problem areas.
Sunscreen should be worn all over the face, including the ears, recommends New York City-based board-certified dermatologist Debra Jaliman, MD. “Cover your entire face in sunscreen, as well as your neck and hands,” she says. “You can put it on first thing in the morning.”
3. Follow the “two fingers” rule for the face and neck.
Board-certified dermatologist Carmen Castilla, MD, suggests following the “two-finger” rule for your face and neck. Spread sunscreen along your index and middle finger. This amount ensures that your face and neck are protected. “It really doesn’t hurt to put on extra sunscreen. So if you’re not sure you’re getting enough protection, just put on a little more,” she says.
4. The magic SPF number is 30.
“The American Academy of Dermatology always recommends an SPF of 30 because it has been clinically proven to be adequate protection to reduce or minimize the adverse effects of sunlight,” says David Colbert, MD, a researcher at The New Yorker Board Certified Dermatologist.