Of all the beauty commandments, there is one in particular that stands above the rest: wear sunscreen every day. Why? Sunscreen is for more than just looking your best—it's also a matter of health and safety. But, how does sunscreen work and which one should you choose?

There are a lot of misconceptions about sun protection out there. To debunk those myths and lay out the real truth about sunscreen, we break down why you should be using it, what different kinds are out there in the market, and best application practices so that you can easily incorporate it into your daily routine. You can thank us later.

Your Best Bet Against Skin Cancer

Before getting down to the details on how sunscreen works, it's important to talk about why you should be wearing it every day. Sunscreen is proven to reduce your risk of melanoma, the most dangerous form of skin cancer, by 50 percent. It is also proven to lower your risk of squamous cell carcinoma, which is the second most common form of skin cancer, by approximately 40 percent.

Other known benefits of wearing sunscreen every day include reducing premature signs of aging, such as wrinkles and dark spots. Sunscreen is also known to help make hyperpigmentation and acne scars less visible. The benefits are far too great to ignore, so don't skimp out.

Chemical vs. Mineral Sunscreens

Sunscreen works to give your skin a protective layer against the sun's harmful ultraviolet (UV) rays. There are two types of sunscreen out in the market—chemical and mineral—and they each contain ingredients that handle UV radiation differently.

Chemical sunscreens, which contain ingredients like Avobenzone and Octisalate, soak into the skin and absorb UV rays, dissipating them as harmless heat before they can damage your skin.

Mineral sunscreens, which contain ingredients like Zinc Oxide and Titanium Dioxide, sit on your skin and form a barrier, actually reflecting and scattering UV rays before they penetrate your skin. Some find that mineral formulas are gentler on sensitive skin, and others prefer them for their non-oily feel.

You may hear that chemical sunscreens contain harmful ingredients (oxybenzone, for example, is sometimes cited as a hormone disruptor), but doctors have found no conclusive evidence for these claims. Both chemical and mineral sunscreens are completely safe for the skin and are equally effective when used properly.

Reading Your Labels

The SPF, or sun protection factor, of a sunscreen is a measure of how long the product delays the sun's UVB rays from reddening your skin. A sunscreen with an SPF of 30, for example, will keep you from burning for 30 times longer than if you had used no sunscreen on the same day.

Additionally, not that SPF 15 blocks about 94 percent of rays while SPF 30 blocks about 97 percent, with additional protection decreasing as you go up to SPF 40 and 50. Most Dermatologists recommend you opt for SPF 30 at a minimum. If you find yourself outdoors and under the sun or in the water a lot, look for formulas that are water-resistant. Always remember to reapply every two hours or immediately after you swim or sweat excessively; sunscreen loses its potency when wet and can be washed off easily.

One final thing you should be on the lookout for in a sunscreen is broad-spectrum protection. This simply means the product protects against both UVA rays, which are responsible for tanning, wrinkles, and dark spots, as well as UVB rays, which are responsible for causing sunburn. You'll want to make sure your sunscreen protects you from both, so something like EltaMD UV Daily Broad-Spectrum SPF 40 is great to incorporate into your everyday routine.

Follow the 5 Ws (and 1 H)

In terms of application practices, the Skin Cancer Foundation suggests you follow the 5 Ws, which we've expanded on below.

Who: Sunscreen is for everyone. This means that regardless of age, gender, or skin color, you should be using sunscreen.

What: A broad-spectrum product with an SPF of 15 at the bare minimum. SPF 30 is highly recommended for its added protection and staying power.

When: Every day, rain or shine, summer or winter. If the sun is up, you should have sunscreen on your skin.

Where: Everywhere and anywhere your skin is exposed to the sun, even if you don't plan on being outside.

How: Apply to any exposed skin. For a full-body application, like you'd need for a beach day, use about one ounce of product (two tablespoons) each time.

Why: To prevent painful burns and reduce the chance of skin cancer and lasting skin damage.

There you have it: the complete breakdown of how sunscreen works and how to select one. Beyond these tips, it's all about personal preference. Test different sunscreens to see which ones work best with your skin and fits most seamlessly into your routine. And remember, if you have any questions, a Dermatologist would be happy to see you and help build a regimen to keep you safe and glowing for years to come.


  • Audrey Noble

    Audrey Noble is a New York City-based reporter specializing in features, celebrity profiles, and beauty topics. Her work has appeared in Vogue, Harper's BAZAAR, Allure, Vanity Fair, Refinery29, and more. She is a University of Southern California alumna with bachelor's degrees in print journalism and creative writing.

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