Chemical Vs. Physical Sunscreens: Pros And Cons

-
physical sunscreens

You know how important it is to wear sun protection daily, but between physical sunscreen and chemical sunscreen, how do you know which one is the best kind to use? Which sunscreen is least likely to cause breakouts or irritate sensitive skin? Which one will give your skin the most protection? There’s a big debate as to which type of sunscreen is the best, so this post will explain the main differences and help you make an informed decision in the physical vs chemical sunscreen battle.

Physical sunscreen

Unlike chemical sunscreen, physical sunscreen contains active mineral ingredients, such as titanium dioxide or zinc oxide. Physical sunscreens work by sitting on top of the skin to deflect and scatter damaging UV rays away from the skin. This is why they are often referred to as  physical blockers, because they sit on top of your skin like a shield.

Physical sunscreen pros:

  • Offers protection against both UVA and UVB rays and is naturally broad spectrum
  • Protects from the sun as soon as it’s applied, no wait needed
  • Lasts longer than chemical sunscreen when exposed to direct UV light (but NOT when doing physical activities that cause the skin to get wet or sweat)
  • Less likely to cause a stinging or irritation on the skin, making it better for sensitive skin
  • Better for those with heat-activated skin (like those prone to rosacea and redness) since it deflects the heat given off by the sun along with UV rays
  • Less likely to be pore-clogging, making it ideal for blemish-prone skin types
  • Has a longer shelf life than chemical sunscreen

Physical sunscreen cons:

  • Can rub off, sweat off and rinse off easily, meaning more frequent reapplication is needed when outdoors
  • May leave a white-ish cast on the skin, making some formulas incompatible with deeper skin tones
  • May be too chalky and opaque for daily use under makeup
  • May create an occlusive film, which results in increased perspiration during physical activities and, therefore, causes the sunscreen to wear off more quickly
  • Tends to be thicker, which will require more effort to rub in
  • Can cause white drips to show on the skin when sweating
  • Won’t offer full protection unless applied generously and accurately, because UV light can get through gaps in the sunscreen molecules and penetrate the skin (FYI, here’s how much sunscreen you should be applying to your face and neck)

Chemical sunscreen

Chemical sunscreen contains organic (carbon-based) compounds, such as oxybenzone, octinoxate, octisalate and avobenzone, which create a chemical reaction. Chemical sunscreen works by changing UV rays into heat, then releasing that heat from the skin. As a result, UV rays are not absorbed by the skin. Because of this, they are often referred to as chemical or organic absorbers.

Chemical sunscreen pros:

  • Tends to be thinner and, therefore, spreads more easily on the skin, making it more wearable for daily use (especially under makeup)
  • Less is needed to protect the skin, because there is no risk of there being gaps between the sunscreen molecules after application
  • The formula is easier to add additional treatment ingredients to, such as peptides and enzymes, which offer other skin-protecting benefits

Chemical sunscreen cons:

  • Can possibly cause an increase in existing brown spots and discoloration due to the chemical reaction that increases internal skin temperature (Yes, heat can make brown spots worse.)
  • Requires 10 minutes after application to become effective and create a protective film over the skin
  • Increased chance of irritation and stinging (especially for those who have dry skin with a damaged moisture barrier) due to the multiple ingredients combined in order to achieve broad-spectrum UVA and UVB protection
  • The higher the SPF (such as formulas of SPF 50 or greater), the higher the risk of irritation for sensitive skin types
  • The protection it offers gets used up more quickly when in direct UV light, so reapplication must be more frequent
  • Increased chance of redness for rosacea-prone skin types because it changes UV rays into heat, which can exacerbate flushing
  • The chemical ingredients oxybenzone and octinoxate have been banned in Hawaii for posing a risk to coral reefs when worn while swimming in the ocean. This applies to water-resistant beach sunscreens only and not daily use sunscreens or makeup with sunscreen. (Pro tip: When at the beach, this surprising thing should be your first defense against damaging sun exposure)
  • Depending on the formula, could be pore-clogging
  • Can cause stinging if it drips into the eyes from sweating

Lightweight sunscreen that won't clog pores

So which is better, chemical or physical sunscreen?

The simple answer is… the one that feels the most comfortable on your skin. If you’re an oilier skin type like #1, #2, #3 or #4, you’ll enjoy wearing one that is lightweight and not greasy. If you consider yourself sensitive and your skin gets red easily, you’ll want to find one that doesn’t sting the skin or make it feel irritated. If you have clogged pores and bumps, you’ll obviously want one that doesn’t cause that. If your skin color is deeper in tone, you’ll want a sunscreen that doesn’t look chalky on the skin. Both chemical and physical sunscreens do a great job at protecting your skin from the sun, just find one that feels good enough on the skin that you’ll want to wear it every day.

You’ll want to check for compatibility by doing a patch test before using any new sunscreen all over your face.

Which type of sunscreen offers the best UVA and UVB protection?

This is a huge debate among scientists. Currently, the FDA is taking steps to establish new standards of measuring the effectiveness of sunscreens more accurately in an effort to educate consumers on how best to prevent the detrimental effects of exposure to UV radiation. For now, however, both physical and chemical sunscreens will do a great job of protecting your skin, as long as you are applying them generously every morning and reapplying throughout the day. Mineral powders infused with sunscreen like titanium dioxide are really easy to dust on for reapplication over makeup.

Which SPF number is the best to use?

Higher numbers on labels are more about marketing. In fact, the FDA is proposing to ban sunscreens that are labeled with an SPF number higher than 50, since there is no scientific evidence showing that they offer any more protection than lower numbers. I recommend a minimum SPF of 30 and a maximum of 50.

My personal sunscreen recommendations

For daily use under makeup

Weightless Protection SPF 30. This uses both physical and chemical sunscreen filters. The zinc oxide (physical sunscreen) creates a lightweight finish with natural antimicrobial agents for my clogged pore-prone skin.

The octinoxate and octisalate (chemical filters) makes it spreadable and easy to apply, so it is ideal for daily use under makeup. Because Weightless Protection SPF 30 is not a purely physical sunscreen, celebrities like Sofia Vergara and Demi Lovato, who both have medium skin tones, find that it doesn’t leave a white-ish cast on their skin. They both use it faithfully in their skincare routines every day.

“Sun protection is so important. I love Weightless Protection SPF 30. —Sofia Vergara.

To enhance the effects of chemical or physical sunscreen, I faithfully wear Vitamin C&E Treatment underneath my SPF. Not only does it protect my skin from damaging free radicals, but it helps make the sunscreen even more effective. Duke University Medical Center researchers determined that using a lotion or serum with both vitamins C and E under sunscreen actually provides four times the protection of sunscreen alone. Look at what happened when I applied this vitamin C and E serum to an apple!

For easy reapplication throughout the day

I dust on an SPF-infused mineral powder every few hours throughout the day. ColoreScience and Jane Iredale make ones that I like, but you can also use any pressed or loose powder makeup that contains titanium dioxide (titanium dioxide is a physical blocker).

For outdoor use when I’m sweating or swimming

La Roche-Posay Anthelios SPF 50 Mineral Ultra Light Sunscreen Fluid. Since Weightless Protection SPF 30 is meant for daily use and is not water-resistant, I’ll switch to something that will hold up better. This sunscreen uses zinc oxide exclusively, so it is a purely physical sunscreen. It rubs in fairly well but can leave a little white-ish cast on my face. They do make it in a tinted version, so sometimes I’ll mix in a bit of that if the zinc oxide is showing up too much.

Antioxidant Serum

I hope this gives you some helpful insight into understanding the differences between physical and chemical sunscreens. Every skin type is different, so you just have to experiment with various formulas. There is one out there that is perfect for you. Ultimately, the best sun protection for preventing premature wrinkles and the risk of skin cancer comes from finding a sunscreen you enjoy wearing.

Read my sweat-proof sunscreen tricks that WON’T clog your pores

Renée Rouleau

Celebrity Esthetician & Skincare Expert
As an esthetician trained in cosmetic chemistry, Renée Rouleau has spent 30 years researching skin, educating her audience, and building an award-winning line of products. Trusted by celebrities, editors, bloggers, and skincare obsessives around the globe, her vast real-world knowledge and constant research are why Marie Claire calls her “the most passionate skin practitioner we know.”