Confused by Sunscreen Labels? Learn what’s In a Name?

Before you head out into the sun this summer, take a few minutes to learn how to protect your skin.

Protecting your skin daily with sunscreen may sound simple enough, but when it comes to deciphering labels and choosing the most effective products available, you may start wishing you’d paid more attention in chemistry class. As you scan the tiny print of long, alien words, which ones do you want to find in the sunscreen you’re using, and what do the various ratings mean? Debra Wattenberg, MD, a New York City dermatologist whose specialties include prevention and early detection of skin cancer, explains what sun protection factor (SPF) numbers mean for consumers.

“There are three types of ultraviolet rays: UVA, UVB, and UVC. The SPF rating measures the protection a sunscreen offers against UVB rays, the ultraviolet radiation that causes sunburn,” Dr. Wattenberg says. The number—be it 15, 30, or 70—is a comparison of how long it takes unprotected skin to become red versus skin that is protected.

The Skin Cancer Foundation ( puts it this way: “If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer—about five hours.” Practically speaking, to achieve the maximum benefit, sunscreen needs to be reapplied every two hours, and no sunscreen will block all UV rays. Also, judging your sun-safety by whether or not you turn red is not an accurate measurement, as the red hue of your skin is a reaction to only UVB rays and does not reflect the damage of UVA rays.

Given this background, what guidelines should we follow? Dr. Wattenberg says that while an SPF of 15 or higher is considered acceptable UVB protection, she recommends using a higher number, as most people do not apply enough sunscreen (or as much as testers in large-scale studies have applied). Currently, she says, there is no approved UVA measurement.

She also reminds us of the importance of using sun protection on a daily basis: “Sunscreens should be used by everyone, every day. They should be applied at least 30 minutes prior to going outside, and they should be reapplied after swimming or heavy sweating.”

It goes without saying that the best defense is, of course, to stay out of the sun if possible. “Sun protection shouldn’t stop with sunscreen,” Dr. Wattenberg says. It is important to physically block the sun from your skin.” Suiting up in long pants, long-sleeved shirts (ideally with collars that can be turned up to protect your neck), and accessories like wide-brimmed hats and UV-protective sunglasses will limit direct sun exposure while you enjoy your time outdoors.

Choose sunscreens that contain the following ingredients:

  • UVA blockers
  • UVB blockers
  • A combination UVA and UVB sunscreens
  • Mexoryl® (ecamsule)
  • Avobenzene
  • Oxybenzone
  • Octocylene
  • Physical blockers such as zinc oxide and titanium oxide