Sunscreen vs sunblock: What’s actually the difference?

Which one is better, sunscreen vs sunblock? And what exactly is the difference? 

They sound like the same thing, and we'll be honest, we used to think they were until we found out that they're really not. One of them absorbs into the skin, while the other sits on top of the skin, meaning they protect you in different ways. 

The truth is, they both have their strengths and weaknesses. For you, the best sunscreen for face coverage will depend on your personal preferences about your skincare routine. We have our personal favourite, which is the Kiehl's Ultra Light Daily UV Defense Aqua Gel SPF50 and you'll probably have yours too. The best way to make an informed decision is to find out exactly what’s in both and what makes them so different.

To help you out, we got some experts to break it down so we can finally all be on the same page. Here's what you need to know about sunscreen vs sunblock... 

Sunscreen vs sunblock:  one absorbs, one blocks

Sunscreen and sunblock are different because of what they’re made of and the way those ingredients interact with the skin.

When people say sunscreen, they are usually referring to “chemical” sunscreen—a light-weight formula that spreads fairly easily and is made of one or more of the following: oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate, according to the American Academy of Dermatology Association.

On the other hand, “physical” sunscreen is usually known as sunblock. It’s usually thicker, heavier, and is composed of minerals like titanium dioxide or zinc oxide.

But how do these different compositions impact sunscreen vs sunblock?

“Sunscreen works by being absorbed into the skin, aiming to prevent the sun’s UV rays from damaging the skin’s dermal layers,” explains Sanem Ahearn, the head of marketing at Colorescience. “On the other hand, sunblock sits on top of the skin to act as a barrier between UV rays and your skin.”

Essentially, chemical sunscreen filters UV light and releases it from your skin. Physical sunscreen, or sunblock, acts as a barrier that deflects UV rays away from your skin. However, neither of them are any use at all if they're out of date, so make sure you always check your sunscreen expiration. And just for the record, if you often ask yourself  'does sunscreen prevent tanning?' then rest assured, the answer is no. 

Pros and cons of sunscreen

Sunscreen and sunblock alike are effective at protecting skin from harmful UV rays, so we’ll consider that a pro for both of them. They both help to prevent sunburn and subsequent skin cancer.

A pro for sunscreen is how easily it absorbs into the skin, making it invisible, whereas sunblock sits on top of the skin and can leave behind obvious white streaks.

The con of sunscreen is significant, however. “It is considered to be potentially harmful,” explains Dr. Robert Goldman, a cosmetic surgeon. “Some chemicals involved in the making are observed to have adverse effects on one’s skin.”

Oxybenzone is the most concerning chemical in sunscreen, according to the American Cancer Society. It can cause allergic reactions in some users, and there is evidence suggesting it might even have an impact on levels of free radicals. Sunscreen can also have a negative effect on the environment, specifically coral reefs.

Pros and cons of sunblock

If you find yourself having allergic reactions to most sunscreens, it’s possible that sunblock is the better option for you.

“Sunblock is mainly more effective for people with sensitive skin and children,” says Dr. Goldman. It’s mineral-based, which means it’s less harsh on the skin and can cause fewer issues for those who are sensitive or have allergies.

However, “Sunblocks lie on the skin and are often opaque or visible,” adds Dr. Goldman. Using sunblock at the beach or pool might not be much of an issue. But visible white stripes don’t make the best companion to that cute new outfit when you’re heading for a day out. 

It can also feel a little heavy you moisturize too, which raises yet another question: Should you use suncreen or moisturizer first? That's a topic for a whole different day. 

Ultimately, both sunscreen and sunblock are important...

So whichever you choose, use!

When it comes down to it, sunscreen and sunblock are both great options. They both protect your skin from UV rays—whether by absorbing and releasing them or by blocking them entirely. Your choice will depend on your skincare preferences.

Experts can agree on one thing, though—whichever option you choose, use it regularly.

“Sunscreen or sunblock should absolutely be part of your skincare routine if you spend a lot of time outside,” advises Keith Eneix, president of TautUSA. “Even if not directly in the sun, your skin can still be affected by the sun’s damaging rays, so it’s always better to be cautious.”

So before you head out for the day, don’t forget to put on the most important makeup you have—your sunblock or sunscreen.