Health Library

Sunscreen basics

Protect your skin from damage: Know which sunscreen to choose and how to use it.

Using sunscreen is one of the easiest things you can do to protect your appearance and your health.

The right sunscreen used properly can help protect your appearance by reducing your risk of sunburns, age spots and wrinkles. It can also protect your health by reducing your risk for skin cancer.

How sunscreen works

Sunscreen offers protection from ultraviolet (UV) rays in two main ways, according to the American Academy of Dermatology (AAD):

  • Reflecting UV rays with ingredients such as zinc oxide and titanium dioxide. Products with those ingredients are physical sunscreens.
  • Absorbing UV rays with substances such as oxybenzone and avobenzone. Products with those ingredients are chemical sunscreens.

Different types

Oils, creams, lotions, pastes, ointments, sticks and sprays—those are just a few of the sunscreen formulations you can choose from.

Zinc oxide and titanium dioxide formulations may work better for children and those with sensitive skin. Creams are a good choice for the face, notes the AAD, while stick sunscreen works well around the eyes, and gels are great for hairy areas like the scalp and men's chests.

Ultimately, sunscreen will do no good if you don't use it. So choose a formulation that you know you will pick up and apply again and again.

Check the label

Whatever type of sunscreen you pick, make sure to check the label for a few key indicators:

Broad spectrum. These words on the label mean the sunscreen protects from both UVA and UVB rays.

Sun protection factor (SPF) of at least 30. No sunscreen blocks 100% of the sun's rays, but a higher SPF means better protection.

Water-resistant for up to 40 or 80 minutes. This means your sunscreen will hang in there through heavy sweating and swimming—at least for a while. Follow the directions and reapply as recommended.

Apply every day

Sunscreen only does the trick if you use it properly. So the next time you slather on the sunscreen (something experts recommend you do every day), check the directions. In general, you'll need to:

  • Use around an ounce of sunscreen to cover exposed areas. That's about the amount that would fill a shot glass.
  • Apply sunscreen about 15 minutes before heading outdoors. That gives it time to take effect.
  • Reapply about every two hours.
  • Pay attention to coverage on those out-of-the-way areas: ears, backs of knees, tops of feet and the top of your head if your scalp shows.

While the sun may be elusive during the winter months, UV rays are always present. Keep using sunscreen even on days that are overcast or cool. Sun can reflect off snow quite intensely. And even on cloudy days, up to 80% of UV rays can still penetrate skin, according to the AAD.

Reviewed 11/7/2023

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