Physical vs Chemical Sunscreen: What Derms Recommend

By now, it is well known that sunscreen is a necessary part of any skin care routine. Using sunscreen on a daily basis can help protect your skin from skin cancer and photoaging. But how do you know which type of sunscreen you should be using? Below, we discuss what board-certified dermatologists Dr. Sheila Krishna and Dr. Lana Kashlan say about physical vs chemical sunscreen and why physical sunscreen is the way to go.

Why Do We Need Sunscreen?

We’ve all grown up knowing that we have to use sunscreen at the beach but, for some, it takes a bit more getting used to as daily skincare practice. Sunscreen, however, is one of the most important steps that we can take to protect our skin because of its ability to prevent skin cancer. Sunscreen blocks ultraviolet radiation, and can reduce the incidence of both melanoma and non-melanoma types of skin cancer. This makes it one of our most powerful tools in protecting ourselves from harmful rays.

In addition to skin cancer prevention, sunscreen plays an important role in preventing photoaging. Over time, exposure to the sun can cause fine lines, wrinkles, hyperpigmentation, and rough or uneven skin textures. Sunscreen helps to protect your skin from overexposure and premature aging, giving you that coveted dewy skin glow.

Physical vs Chemical Sunscreen

There are two general categories of sunscreen–physical sunscreen and chemical sunscreen–and it can be challenging to understand which one is the best choice for you. While you could try googling ‘physical vs chemical sunscreen reddit,’ we’d recommend taking a dermatologist’s advice over random people on the internet.

Physical sunscreen, also known as mineral sunscreen, is typically associated with the thick, white creams that we used as kids. Consequently, chemical sunscreens have gained popularity in recent years because they tend to have thinner formulas that absorb into your skin and provide a lighter base for other products.

The consistency, however, isn’t the only difference between physical and chemical sunscreen. The key distinction between the two types is actually in the way that they work. Physical sunscreen sits on top of your skin, acting as a shield against the harmful UV rays. The minerals reflect and scatter the sun’s rays away from your skin, preventing sun damage. 

This physical barrier is incredibly effective at protecting the skin, which is why mineral sunscreens are still preferred by most dermatologists. While people have long associated physical sunscreens with an ashy residue, they have come a long way since our youth and there are now plenty that go on clear. 

Chemical sunscreen, on the other hand, absorbs the UV rays and prevents damage to the skin through a chemical reaction that turns the rays into heat that is then released through the skin. As mentioned above, chemical sunscreens are lighter than their mineral counterparts, largely because they are intended to be absorbed into the skin instead of sitting on top as a barrier. 

There are some issues with chemical sunscreens, however. Primarily, they can cause irritation for some people. Additionally, there are concerns about how environmentally friendly many chemical sunscreens are. Studies have shown that chemical sunscreens can remain in water sources, even after it is filtered, and there is concern that they can cause damage to coral reefs. Now, is chemical sunscreen bad? Not necessarily, it’s just not what many dermatologists recommend. 

What to Look for When Choosing a Sunscreen

There are a number of things that you want to look for when choosing a sunscreen. The most important place to start is making sure that you’re buying a sunscreen that is full spectrum or  broad spectrum. This just means that the sunscreen will protect you from both UVA and UVB rays. Some sunscreens can only guarantee protection from one type of ultraviolet rays, which means you won’t be getting the full bang for your buck! This is why a broad spectrum sunscreen is a must have. 

Secondly, you want to make sure that you’re getting sunscreen that is at least 30 SPF or higher. An SPF of 30 will block 97% of the sun’s harmful rays so as long as you’re in that range, you should be good. This is especially important if you’re going to be outside for extended periods of time. 

There are also a few key physical sunscreen ingredients to look for. According to Dr. Sheila Krishna, for “mineral sunscreen, [ingredients] such as zinc, titanium or ferric oxides” are ideal. Even better, “[t]hese are (mainly) reef and body safe.”

In addition to zinc oxide, or other minerals that block UV rays, physical sunscreens generally have very few other ingredients. Often there will be a base of jojoba or coconut oil to allow for easy application and moisturizing. 

Chemical sunscreens usually have much longer ingredient lists, which is one of the reasons that they tend to be more irritating. Some of the ingredients you may see in chemical sunscreens include: oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate. Some of these ingredients have been banned in certain parts of the world because of the environmental damage they may cause. So what’s the best chemical sunscreen? Well, it’s the one that you’ll wear and doesn’t irritate your skin, but this might take some trial and error. 

Finally, it is typically a good idea to look for water resistant sunscreens, especially if you’re going to be swimming. Water resistance helps the sunscreen last longer before reapplication is needed. Physical sunscreen in particular is more prone to getting rubbed or washed off, so water resistance is key.

Why Sunscreen is Important When Using Retinoids

Retinoids are another great tool for preventing or reducing the effects of photoaging such as fine lines, dark spots, and uneven skin texture. But they can also make you more sensitive to the sun, since they work by removing oils and dry skin cells from the surface of your skin. This is why applying sunscreen daily is extra important when you’re using a retinoid cream. 

Physical sunscreens that contain zinc or titanium oxide will also be the better choice if you are using retinoids. Because they sit on top of the skin and act as a protective barrier, they are less likely to cause any irritation because they don’t get absorbed into the skin.

How to Use Sunscreen With Retinoids

Whenever you are using retinoids, you’ll want to apply a small, pea sized portion on clean, dry skin at night before bed. If you are new to using retinoids, it’s best to start by applying the cream only a few times a week and work up to daily application. 

15-20 minutes after applying the retinoid cream, you should apply a moisturizer. This helps to immediately replenish cells and rebuild moisture as you sleep. 

Dermatologists also recommend applying a sunscreen of SPF 30 or higher daily when using retinoids. As discussed above, this is generally a good practice, whether or not you’re using retinoids, but it is especially important if you are using them. Because retinoids may temporarily strip down some of the skin’s natural barriers, applying a layer of sunscreen every 1-2 hours is key to ensuring that you’re not overexposing your skin to harmful UV rays and putting yourself at risk for more photoaging effects!

How to Properly Use Sunscreen

One of the number one reasons that people report low satisfaction with sunscreen, is improper application. While you don’t need to go crazy in applying it, you probably do need to use a bit more sunscreen than you think to ensure that you’re really covering any skin that might be exposed to the sun. 

While the frequency of application will depend on what you’re doing, if you’re going to be out in the sun the entire day, you should plan to reapply every 1-2 hours. If you’re swimming or engaging in physical activity where you’re sweating a lot, you may need to reapply more frequently. 

Because physical sunscreen rests on top of the skin instead of being absorbed into it, it is also best to give it about 20-30 minutes to dry before leaving the house in the morning or engaging in any activities that could cause it to rub off. 

You can also use chemical and physical sunscreen together if you so choose. Some people prefer this method for extra protection because physical sunscreen does tend to come off more easily than chemical sunscreen since it isn’t being absorbed into the skin. However, this isn’t really necessary if you’re getting a good physical sunscreen and remember to reapply a few times throughout the day. 

So what’s the verdict? When considering mineral vs chemical sunscreen, dermatologists tend to go for mineral sunscreen. “I prefer physical sunscreens,” says Dr. Lana Kashlan, “they’re the best at blocking UVA and UVB completely, zinc oxide is gold standard.”

It’s hard to argue with that endorsement. Dear Brightly’s new derm-tested, SPF 30 mineral sunscreen, NeverSkip, has everything you need. Try it today, we promise you won’t be disappointed.

References:

Sander M, Sander M, Burbidge T, Beecker J. The efficacy and safety of sunscreen use for the prevention of skin cancer. CMAJ. 2020;192(50):E1802-E1808. doi:10.1503/cmaj.201085

Shanbhag S, Nayak A, Narayan R, Nayak UY. Anti-aging and Sunscreens: Paradigm Shift in Cosmetics. Adv Pharm Bull. 2019;9(3):348-359. doi:10.15171/apb.2019.042