Decoding the label

Sunscreen options may seem endless, with many different brands, formulas and ingredients to sift through. However, that means everyone can find a sunscreen that works for their skin, budget and lifestyle. Deciphering a sunscreen’s label is the first step to finding your perfect match.

The first thing to consider is SPF (sun protection factor). The SPF number tells you how long the sun’s UVB radiation would take to redden your skin when using the product as directed versus the amount of time without any sunscreen. Ideally, if you apply an SPF 15 sunscreen it would take your skin 15 times longer to burn than if you weren’t wearing sunscreen.

A sunscreen with a minimum of SPF 15 is fine for days when you’re mostly indoors. For days spent outside, choose a water-resistant formula with an SPF of at least 30. For people who have a history or high risk of skin cancer, genetic diseases such as albinism or xeroderma pigmentosum or certain immune disorders, an even higher SPF may be appropriate.

The second thing to check for on a label is the term “broad spectrum,” which means the product protects against both UVA and UVB radiation. Both types of UV rays penetrate the skin and cause skin damage that can lead to skin cancer.

Once you’ve decided on your SPF and checked that a product is labeled broad-spectrum, you can decide on other qualities based on personal preference and lifestyle. For example, look for a mineral-based product containing zinc oxide and/or titanium dioxide if you have sensitive skin—they’re less likely to cause skin reactions than some other active ingredients. However, some people prefer the so-called chemical sunscreens which utilize ingredients like avobenzone and octisalate and can be easier to apply than mineral formulas. Many sunscreens combine both types of active ingredients.

Sunscreens also come in lotion, powder, spray and stick form.

How much, how often?

Sunscreen won’t protect your skin if you don’t use it properly, so understanding application is vital.

Use one ounce of sunscreen, which is about the amount that would fit into a shot glass, to cover the entire body. For the face, a nickel-sized dollop works.

Slathering on sunscreen in the morning isn’t enough to protect you all day. The Skin Cancer Foundation recommends applying sunscreen 30 minutes before going outside, then reapplying every two hours and immediately after swimming or sweating. No sunscreen is waterproof, only water-resistant, so be aware of how long the product claims to protect against moisture.

Studies that examine the effect of sunscreen use on skin cancer risk have consistently delivered encouraging results. One example is a rigorous study spanning the course of a decade that showed daily use of an SPF 15 or higher sunscreen reduces the risk of developing melanoma by 50 percent. However, no single method of sun protection can protect you completely. It’s recommended to also seek shade and cover up with clothing, wide-brimmed hats and UV-blocking sunglasses in addition to daily sunscreen use.