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What is the difference between physical and chemical sunscreens? Which one is better? What is the best sunscreen for your skin type? You already know you should be protecting your skin from UV rays daily, but here are some key points you may not know.
As someone with oily, acne-prone, and sensitive skin, I've been paying a lot more attention to what ingredients I put on my face because when my skin doesn't like a product, it shows. We're talking redness, tingly sensations, breakouts, the works. Learning about the science behind skincare is a huge interest of mine. I want to share the knowledge I've learned with you all to ensure you make a more informed decision next time you use sunscreen.
Physical versus Chemical Sunscreen
The easiest way to distinguish between physical and chemical sunscreens is by looking at the active ingredients. Physical sunscreens contain mineral inorganic compounds, like zinc oxide or titanium dioxide. Chemical sunscreens are made up of organic compounds, like octylcrylen, avobenzone, oxybenzone, octisalate, and octinoxate.
When I say organic, I mean it scientifically, not in the marketing sense. Been a while since your last chemistry class? Same. Let's refresh.
- Organic compounds: any chemical compounds that contain carbon
- Inorganic compounds: any compound that is not organic
For the sake of simplicity, I will be referring to them as physical and chemical throughout the rest of this post.
Physical sunscreens reflect UV rays whereas chemical sunscreens absorb UV rays. What does this mean? Basically, the former is less likely to irritate your skin since it scatters sun-rays whereas the latter can increase irritation because it changes UV rays into heat on the skin's surface, then releases heat from the skin. While both types protect your skin from sun exposure, there are definitely pros and cons for each formula.
- Absorb quickly into skin
- Thinner consistency
- Spread easily on skin
- Need less product to cover face
- Less likely to leave a white cast
- Absorb UV rays
- Trap heat onto skin
- Can increase discoloration and brown spots from over-heating skin
- Need about 20 minutes before working
- Higher risk of skin irritation with use of SPF 50+
- More likely to irritate dry, acne-prone, rosacea-prone, and sensitive skin
- May clog pores for oily skin
- Can sting if drips into eyes
- Can increase redness
- Shorter shelf life
- Reflect UV rays
- Works immediately
- Last longer in direct UV light as long as skin isn't wet or sweaty
- Less likely to clog pores
- Less likely to irritate skin
- Longer shelf life
- Ideal for acne-prone, heat-activated (redness and rosacea), and sensitive skin
- Thicker consistency
- May leave a white cast
- May not be compatible with medium and dark skin tones
- Can rub off easily from sweat and cause white drip marks
- Need more frequent reapplication
Does higher SPF mean the sunscreen protects my skin more?
Quite the contrary. Surprisingly, an SPF between 30 and 50 is all you need to protect your skin. Any number higher than that is marketing geniuses at work trying to convince you that more is better, whereas higher SPF's actually increase your chances of skin irritation, particularly if you have sensitive skin. There is no scientific evidence that an SPF higher than 50 protects your skin more. Keep that in mind next time you browse for sunscreen.
Does layering a physical sunscreen on top of a chemical sunscreen protect skin more?
There isn't much research about layering sunscreens, so that's up to you to form your own opinion. One layer of sunscreen is enough to protect your skin from the sun.
How much sunscreen do I need to apply to my face and body?
Two tablespoons is the magic number for your face and body. For your face, a nickel sized amount is ideal. Remember to reapply every two hours, or more frequently if you're sweating it off, for maximum effectiveness.
What are the best sunscreens?
It honestly comes down to trial and error because everyone's skin is different, so experiment until you find the best one that works for you. Watch my YouTube video to learn more about my top three essential sunscreens which work well under makeup and do not irritate my skin. Below are my favorite sunscreens (denoted by *), as well as top rated ones based on customer reviews from Sephora and Target.