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Chemical vs. Mineral Sunscreen: How They Work to Protect Your Skin

Jun 01, 2023

Chemical vs. Mineral Sunscreen: How They Work to Protect Your Skin - Stripes Beauty

After months of powering through the winter cold, spring rain, and those April days where the weather’s beautiful at 1pm but totally freezing by dinnertime, summer has finally arrived. But before you grab your beach umbrella and plant yourself by the water ‘til Labor Day, you might want to reconsider your sunscreen routine — especially if you haven’t changed it since your 20s. 

“As we get older, our skin naturally gets drier,” says dermatologist Dr. Sarvenaz Zand. “So, youll  definitely want your sunscreen to be more hydrating.”  

Sun damage also becomes apparent more quickly as we age — so while going out in the sun without adequate protection in your younger days might have led to a tan or rosy glow, going out in midlife sans sunscreen can lead to freckles and sun spots that can appear almost instantly.  

“The effects of the sun are much more accelerated [now], because our skin repair mechanisms slow down as we're older,” says Zand. “And so, you'll see the evidence of it faster.” 

This doesn’t mean you have to spend all summer hiding indoors — it just means it’s time to update your sunscreen game.  

Mineral vs. chemical sunscreen 

You’ve probably heard a lot about mineral sunscreen (a.k.a. physical sunscreen) in recent years, especially after some concerning recent studies suggest that ingredients in chemical sunscreen may have potentially harmful side effects, and can be easily absorbed into the bloodstream through the skin. 

Mineral sunscreens contain titanium dioxide and/or zinc oxide and literally sit on top of the skin, blocking and reflecting the sun’s UV rays by creating a physical barrier between sun and skin. This functions differently than chemical sunscreen, which absorbs into the skin; its ingredients then prevent sun damage by absorbing UV rays before the body can.  

However, because it provides a physical barrier, if you choose to use mineral sunscreen, it must be applied densely, over any exposed body part — far more densely than those of us who usually use chemical sunscreen are used to applying.

How much should you use? “When it comes to mineral sunscreen you're supposed to be using an ounce, or a shot glass’s worth, to cover your whole body,” says Zand. Chemical sunscreen, because it operates by a different mechanism, doesn’t require quite so heavy of an application to work.

Zand also notes that the face is only about 2% of the whole-body surface area — “as dermatologists, we think about the risk to us of exposure to chemicals in relation to what percent of our body surface is exposed.” So, for some, the right choice might be using a chemical sunscreen when only the face is exposed, but a mineral sunscreen on beach or hiking days, when much of the body will be exposed to the sun. 

If you opt for mineral sunscreen this summer, make sure that you’re applying it thoroughly and using enough of it. Though mineral sunscreen is often known for leaving a “white cast” on the skin of users, many brands offer a cast-free or tinted versions, which are far less noticeable and can even be used like a foundation or primer in your makeup routine. 

Spray-on vs. lotion sunscreen 

Spray-on sunscreen has been a gamechanger for many of us in recent years — especially if you have children who act like standing still long enough to be covered in lotion sunscreen is a punishment on par with a tax audit. But are spray-ons as effective as the old-fashioned kind of sunscreen? 

The short answer is: yes…but only if applied properly.  

“If [spray-on sunscreen application is] done right, definitely, it's just as good [as lotion sunscreen] and so convenient,” says Zand. But it’s easy to get it wrong; many people miss spots while spraying.  If you're spraying it on outside and you're facing the wrong way on a windy day, the mist may miss your skin completely. 

Make sure to follow the exact directions on the bottle, and double check to make sure that it’s actually applied all over. “If it says spray from 6 or 12 inches away, do that,” says Zand. “Make sure you get an even coat. In fact, rub it in, and then you don't have to worry. If all of your skin has a nice, soaked coat after you spray it on, you're good.” 


Protect your chest and body when you reapply sunscreen  

Though many of us stay on top of sunscreen re-application for our kids, we’re not always as good at remembering to do it for ourselves. But “reapplication of sunscreen is probably one of the most important factors for actually preventing sun damage” in midlife, Zand notes.  

When you’re out in the midday sun, it’s key to reapply sunscreen every two hours — so if you’re having a beach day, you’ll want to apply at 10am, 12pm, 2pm and 4pm. A 4pm application, says Zand, should keep you in good shape until 8pm. 

But even if we’re good a protecting our faces from the sun, we may neglect our other parts. Remember to re-apply all over the body, especially any exposed chest skin.  
“When we hit our 30s and 40s, our chests are a magnet for sun damage,” says Zand. “And once that pinkness starts, for a lot of women, it actually doesn't ever resolve. The chest stays pink year-round.”  
If at all possible, Zand recommends covering the chest area with not just sunscreen but clothing, too, like a higher-necked t-shirt or a cover-up. 

How much SPF is enough? 

So do you need a bottle of SPF 100 to truly combat potential sun damage? It turns out that higher is not necessarily better when it comes to SPF. “I think an SPF in the 40 to 50 range is ideal, and all of us just need to be reapplying. I don't think we need a higher sunscreen number,” says Zand. “In fact, the higher the sunscreen number, typically the more irritating or potentially allergenic the product becomes,” due to the higher concentration of ingredients in it. 

Pick something around SPF 50, and make sure that it's one you’ll actually use. Rather than shopping for specific ingredients or brands that promise hydration, “I would make sure it says broad spectrum, SPF 40 or 50, and then shop for feel,” says Zand.  

Making sure the sunscreen has qualities that you’re looking for — that it looks good on your skin, that it doesn’t feel drying once you apply it, that it doesn’t feel irritating or too greasy — is essential in making sure that you actually use it, which is the most important part. “I think when it comes to sunscreen,” says Zand, “convenience almost trumps everything, because it's like a ‘use it or lose it’ situation — use it or you don't get the benefits of it.” 

By Gabrielle Moss 

Gabrielle Moss is the editor at Stripes. She's the author of Paperback Crush: The Totally Radical History of '80s and '90s Teen Fiction. Her work has appeared in the New Yorker, Slate, GQ, Buzzfeed, Marie Claire and elsewhere.


Photo by Mikhail Nilov