What Does SPF Mean & Do You Need It?

Ingredients, Skin Care

Now that the days are getting longer, you’re more likely to experience greater levels of sun exposure. While this means more fun outside activities, it also means you are at a greater risk for sun damage.

Sunscreen is the most essential skincare step. Protecting your skin from the sun is crucial to healthy, youthful, glowing skin. ”

  • Shani

Most of us know sunscreen can help prevent you from getting burned, but how does it work? And what does SPF even mean? I am here to answer those questions and help you determine the best sunscreen for you.

How Does Sunscreen Work?

Basically, sunscreen protects your skin from harmful UV radiation that can cause sun damage. However, there are two main types of sun protection, and each works differently.

Physical Sunscreen

Physical sunscreen, also known as mineral sunscreen, involves physically blocking UV rays from reaching your skin. Because this type of sunscreen blocks UV light, it is also sometimes called sunblock.

Physical sunscreens have active ingredients such as zinc oxide and titanium dioxide. These minerals sit on top of your skin and create a barrier, which is their primary sun protection mechanism. Because they don’t need time to absorb, physical sunscreens typically start working as soon as they’re applied to your skin.

Because physical sunscreen sits on top of your skin, it isn’t designed to absorb into your skin – which means that you can sometimes end up with a whitish cast. The good news is that as technology has evolved, most mineral formulas have managed to remove this cast.

Chemical Sunscreen

Chemical sunscreen works by absorbing UV radiation, converting it into heat, and then releasing that heat back into the atmosphere. Basically, it neutralizes harmful UV rays.

Common active ingredients in chemical sunscreens are oxybenzone, avobenzone, and octinoxate. These ingredients must be absorbed into your skin before they can start screening against sun rays, so we recommend applying chemical sunscreens at least fifteen minutes before stepping out into the sun.

Chemical sunscreens often have lighter formulas and are available in many different forms. You can find chemical sunscreens in both lotion and aerosol forms at most supermarkets.

What Is SPF?

Every sunscreen advertises its SPF, but what do the SPF numbers mean?

SPF stands for sun protection factor, and it describes how effective the sunscreen is at protecting against UV rays. Just like sunscreen comes in all shapes and sizes, you have many different options when it comes to SPF. Typically, SPF can range from eight to a hundred.

To get specific, SPF is a ratio of how long it takes you to get burned wearing the sun protection versus not wearing sun protection in lab conditions. For instance, wearing sunscreen with a sun protection factor of 30 means if you were in a controlled environment, it would take 30 times longer to burn than if you weren’t wearing sunscreen.

So, can you wear higher SPF values for longer? Not exactly.

Even though higher SPF sunscreen theoretically protects you from the sun for longer, many factors are at play. Nature doesn’t behave like a laboratory setting. The sun’s solar energy waxes and wanes throughout the day, so your sunscreen’s protective abilities will also change throughout the day. Because of this, it’s much easier to think of SPF as a percentage of ultraviolet protection.

An SPF rating of 30 is designed to protect against 97% of UV radiation. As you increase in SPF, this percentage changes only marginally. For instance, an SPF of 50 protects against 98% of UV radiation. The overall level of protection doesn’t change much.

Additionally, you will only receive the full amount of SPF protection if you follow the directions on the bottle. For most sunscreens, this means applying one ounce of sunscreen every two hours and immediately after swimming or sweating.

Do You Need Sunscreen?

You don’t get sunburned every time you go outside, so you might think you don’t need to apply sunscreen every day. However, real sun damage happens almost invisibly over time. Here’s why you should always apply sunscreen before leaving the house.

Prevent Visible Signs of Aging

UVA radiation contributes to visible signs of aging, such as fine lines and wrinkles, and it’s also responsible for tanning and freckles. Many people enjoy the look of a natural tan, but the tan often comes at a cost. While you may not see the damage now, it can show up as premature fine lines and wrinkles.

Even SPF 100 can’t protect against 100% of sun rays, but sunscreen can protect against most of them. By wearing sunscreen every time you’re exposed to the sun, you’re helping your skin to look younger, for longer.

Protecting every part of your body that’s exposed to the sun is essential. That’s why I recommend Supergoop! Shine On Lip Screen SPF 40. This handy lip gloss turns any lip color into SPF 40 so that even your lips can stay protected from the sun. 

Protect Against Long-Term Damage

UVA rays don’t just lead to premature aging – they can also lead to serious long-term damage. Several serious skin conditions have been traced back to UVA ray exposure, and it can even affect your general health.

Both UVA and UVB rays can cause free radical damage, also known as oxidative stress. This type of damage occurs when more free radicals attack your body than there are antioxidants in your body’s natural supply. 

Wearing sunscreen can help protect your skin from the harmful effects of the sun rays. Combining your daily SPF with a topical antioxidant like vitamin C can help improve the appearance of your complexion.

Year-Round Protection

Most of us associate sunscreen with summertime days spent by the water. However, harmful UV rays can cause damage year-round.

Reflective surfaces such as snow can amplify the effects of UV rays. When you’re spending a day out in the snow, it’s important to apply sunscreen.

I even recommend wearing sunscreen when it’s cloudy out, or when you’re spending the day inside. Even though you can’t see the sun, you can still be exposed to up to 80% of its harmful rays. Additionally, UV rays can pass through windows, so even when you’re inside all day, you are still being exposed. 

How To Choose the Right Sunscreen

Since SPF can get a little complicated, how do you know which sunscreen will best protect your skin? Here are a few of the top things to consider when purchasing sunscreen.

Your Skin Type

Like all other skincare products, one of the most important things to consider in sunscreen is whether or not it’s tailored to your skincare needs. Since this is a product you’ll put on your face every day, it’s important to ensure it fits your skin type.

If you have oily skin, I recommend a non-comedogenic sunscreen like Control Corrective Oil-Free Sunscreen SPF 30. This lightweight formula is oil-free, so it won’t clog your pores or trigger a breakout. It also contains built-in antioxidants to help improve the appearance of your skin.

On the other hand, if you have normal or dry skin, you may want to consider a heavier formula like Supergoop! Play Everyday Lotion SPF 50. This water-resistant sunscreen doubles as a moisturizer so that your skin is protected and hydrated.

If you have sensitive skin that reacts to skincare products easily, we recommend using mineral sunscreen. Because these sunscreens are made with fewer chemicals, they’re less likely to irritate sensitive skin.

Broad-Spectrum Protection

The FDA only requires sunscreen to protect against UVB rays, which are responsible for sunburn. Although UVB protection helps fight skin damage, you still need UVA protection to fight off premature skin aging.

Sunscreens that protect against both types of UV rays are labeled as “broad-spectrum.” The FDA requires rigorous testing before a sunscreen can call itself broad-spectrum, so anything with a broad-spectrum label is guaranteed to provide UVA and UVB protection.

When purchasing a new sunscreen, I recommend always checking the label to confirm that it offers broad-spectrum protection.

SPF Value

The right SPF value is not one-size-fits-all – instead, it’s based on your skin and the amount of time you spend in the sun. 

If your skin is fair or more prone to sunburn, I recommend a broad-spectrum sunscreen with higher SPF than normal. It’s not an exact science, so it’s always best to err on the side of caution.

Typically, dermatologists recommend SPF 15 if you plan on staying indoors. However, this number increases with more time spent outdoors. 

For instance, if you have a fun day planned out on the town, I recommend at least an SPF 30. However, if you plan on a day outside or on the beach, I recommend at least SPF 50.

When in doubt, I always recommend going for a higher SPF. And since most people go outside at least a little every day, I recommend using a minimum of SPF 30.

Sum it All Up

For both chemical and physical sunscreens, SPF refers to how protected you are against sunburn. Unfortunately, SPF does not indicate how protected you are against premature signs of skin aging. 

To best protect yourself against both types of sun damage, I recommend wearing a broad-spectrum sunscreen of at least 30 that is tailored to your skin type.


What Does the SPF Rating Really Mean? | Australian Academy of Science

Sunscreen | The Skin Cancer Foundation

Questions and Answers: FDA Announces New Requirements For Over-the-Counter (OTC) Sunscreen Products Marketed in the US | Food and Drug Administration