Chemical vs Physical Sunscreen

For most of us, our sunscreen routine is pretty straightforward. Some of us will apply it every day of the year — rain, hail or shine. Others will (hopefully) chuck some on as they head out into the scorching summer heat. Enter the ‘chemical versus physical sunscreen’ debate, which has been circulating lately and things get a little more confusing. Which one is more protective? And should you be making the switch?

Physical sunscreens

Physical sunscreens contain active mineral ingredients, such as titanium dioxide or zinc oxide, which work by sitting on top of the skin to deflect and scatter damaging UV rays away from the skin. They are often referred to as physical blockers.

Pros of physical sunscreens:

  • 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 when in direct UV light (but NOT when doing physical activities that cause the skin to get wet or sweat)
  • Less likely to cause a stinging irritation on the skin, making it better for sensitive skin
  • Better for those with heat-activated skin (like those with rosacea and redness) since it deflects the heat and energy given off by the sun away from the skin
  • Less likely to be pore-clogging, making it ideal for blemish-prone skin types

Cons of physical sunscreens:

  • Can rub off, sweat off and rinse off easily, meaning more frequent reapplication when outdoors is needed
  • May leave a white-ish cast on the skin, making some formulas incompatible for medium to dark skin tones
  • May be too chalky and opaque for daily use under makeup
  • Can create an occlusive film, which results in increased perspiration during physical activities and, therefore, causes it to wear off more quickly
  • Can be thicker, which will require more effort to rub in
  • Can be less protective if not applied generously and accurately since UV light can get between the sunscreen molecules and get into the skin
Chemical sunscreen

Chemical sunscreens contain organic (carbon-based) compounds, such as oxybenzone, octinoxate, octisalate and avobenzone, which create a chemical reaction and work by changing UV rays into heat, then releasing that heat from the skin. They are often referred to as chemical or organic absorbers.

Pros of chemical sunscreens:

  • Tends to be thinner and, therefore, spreads more easily on the skin, making it more wearable for daily use
  • Less is needed to protect the skin because there is no risk of no spaces between the sunscreen molecules after application
  • Formula is easier to add additional treatment ingredients, such as peptides and enzymes, which offer other skin benefits

Cons of chemical sunscreens:

  • Can possibly cause an increase in existing brown spots and discoloration due to a higher internal skin temperature (Yes, over-heated skin can make brown spots worse.)
  • Requires about 20 minutes after application before it begins to work
  • 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
  • May clog the pores for oily skin types

When it comes to sunscreen, it’s hard to say which one is truly the best for your skin since all formulas are not created equal. The best advice is to check for compatibility by doing a patch test before using it all over your face. You simply can’t always judge a product by its ingredient label.