Your Guide to Finding the Best Sunscreen, According to a Dermatologist

What is the difference between mineral and chemical sunscreen?

Let's cut right to the chase, there are two types of sunscreens: Mineral and chemical. And each filters UV Rays and protects from skin damage differently.  

"Mineral sunscreens work by using metals—usually zinc, titanium or iron—to physically block and reflect UV rays," Dr. Wang explained. "Chemical sunscreens absorb UV rays and change their structure to prevent those rays from passing through to the lower layers of the skin."

While the Los Angeles-based dermatologist said that mineral sunscreens are preferred by most people, that doesn't mean you should rule out chemical sunscreens, noting that they "are still quite effective and beat exposing your skin to the sun without any protection."

He also mentioned that chemical sunscreens tend to absorb into the skin more, so they typically don't leave behind a white cast or as much residue. However, advances in formulations have gotten better, as he added, "There are now sheer mineral sunscreens that do not leave a sheen behind."

How can you find the right formula for you?

In short, said Dr. Wang, "The best sunscreen is the one you will use."

But if you want more insight, he said you can never go wrong with a fragrance-free sunscreen. It's an especially great option for sensitive and acne-prone skin types, as the doctor noted "heavy creams and highly fragranced lotions can cause skin irritation."

Moreover, a sheer formula not only feels nice but it's more user-friendly and works well for all skin tones since it doesn't leave behind the dreaded white cast. And as tempting as spray sunscreens can feel, Dr. Wang explained that they require painstaking thoroughness. 

"Spray sunscreens can be as effective as sunscreen lotion, but it requires the user to rub the sunscreen evenly into the skin after it's sprayed on," the doctor explained. "It's often easier to miss a spot with spray sunscreens since they go on clear."

What is the recommended SPF number?

When it comes to daily use and for people who will be indoors most of the day, Dr. Wang suggests a minimum of SPF 42. "If someone is planning to be outside for extended periods of time," he continued, "SPF 55+ is recommended."

His product pick? Shiseido's Urban Environment Vita-Clear SPF 42. He said it gives the skin "powerful protection" and also brightens it since it's infused with vitamin C.

"It blocks UVA, UVB rays and pollution, while visibly boosting brightness and smoothness," he shared. "The weightless, skincare-like texture also has an invisible finish that goes on clear."

How often do you need to re-apply sunscreen?

If you'll be soaking up some sun, then Dr. Wang said it's best to re-apply every two to three hours. However, "if there is intense sweating or water activity," he added, "reapplication every 60 to 90 minutes will give the most effect." However, for those days when you're mostly indoors, you don't need to re-apply SPF as often. Four to six hours will do the trick.

How much sunscreen do you need to apply?

It turns out, it's not as complicated as you thought. "Sunscreen should be applied as a thin layer that takes about 10 seconds to rub in," Dr. Wang pointed out. "If it takes less time than that, it may be too thin of a layer to offer the stated SPF."

At what point in your makeup routine should you apply sunscreen?

Here's the tea: Regardless if your makeup has SPF in it, you still need to wear sunscreen.

"Makeup with built-in SPF is not reliable and does not provide the same level of protection," Dr. Wang explained. "Apply [the sunscreen] as the last step of your skincare routine and before applying makeup. It is highly recommended to apply sunscreen at least 30 minutes before beginning outdoor activities to maximize benefits."

According to Dr. Wang, a lightweight formula like the COSRX Vitamin E Vitalizing Sunscreen SPF 50+ blends seamlessly with other products.