The difference between sunscreens and antioxidants

Published on:  August 20, 2020
Last updated on: June 27, 2021

What's the difference between sunscreens and antioxidants?

You've likely heard that antioxidants are photoprotective, so why aren't they classified as sunscreens?  We're diving into that topic in today's episode, but first, let’s talk about sunscreens. 

What are they?  There are two types of sunscreens: physical and chemical.  And, there’s a difference in how they work to protect skin from UV rays. 

How Physical Sunscreens Work

Physical sunscreens work by sitting on top of your skin and reflecting UV rays off your skin, which keeps those super energetic rays from penetrating through your outer dead skin layers into the living layer of the epidermis and even deeper into the dermis where they can cause damage.

Remember Chief Brody in Jaws?  Do you remember his white nose?  Yep, that’s a physical sunscreen. 

Zinc oxide and titanium dioxide are both physical sunscreens and they're also both minerals, which is why they're sometimes referred to as mineral sunscreens.  Again, these ingredients are intended to sit on top of your skin to physically block UV rays basically by acting as a mirror for the rays to bounce off of. 

The problem with these physical sunscreens is that they leave you with a white cast.  For that reason, micronization, which means grinding up the zinc oxide and titanium dioxide until its a very, very fine powder to prevent creating a visible film layer, was introduced. 

You might have seen a few claims on mineral sunscreens saying non-nano or non-micronized.  The concern with these micronized particles is that they may be able to penetrate the outer layers of skin.  If you remember from episode 1, we talked about the layers of the epidermis and how only the bottom layer of the epidermis, the stratum basale layer, is a living, viable cell layer within the epidermis. 

We also talked about how the outermost layer of the epidermis, the stratum corneum is in fact made of many layers of corneocytes and the number of layers varies by the different parts of your body.  Skin on the inside of your wrist has fewer stratum corneum layers than the skin on your forearm.  Similarly, the skin underneath your eyes has fewer stratum corneum layers than the skin on other parts of your face.

In general, most of your face has fewer layers of the stratum corneum than most other parts of your body.

In these thin skin areas, concerns are even greater about the zinc oxide and titanium dioxide penetrating the outer layers of the skin because they're able to reach living layers more quickly.  Plus, the whole point of a physical sunscreen is to sit on top of your skin and reflect UV rays back into the environment.

For that reason, even though the non-micronized or non-nano physical sunscreens might leave you looking like a ghost, at least they're doing their job.

Before we move on to chemical sunscreens, let’s take a step back for a second and look at how UV rays can damage skin.

How UV Rays Can Damage Skin

UV rays can damage skin in one of two ways:

  • The highly energetic ray can hit DNA causing damage directly to the DNA strand. Simply enough, this is referred to as direct UV damage.
  • The UV ray can also generate free radicals within skin cells, and these free radicals can cause DNA damage. This is known as indirect UV damage because the UV ray itself doesn’t cause the damage, but rather, it generates a free radical that causes the damage.

how UV rays cause skin damage

How Chemical Sunscreens Work

Chemical sunscreens react with UV rays to form free radicals and heat.  Now, that sounds really bad (your cells may not be getting direct DNA damage from UV, but free radicals can cause indirect DNA damage), however, the idea is that chemical sunscreens (like physical sunscreens) also sit on the surface of your skin, so those free radicals would not reach your living cells as long as that sunscreen isn’t absorbed.

how sunscreens protect skin from UV rays

A few common chemical sunscreens are:  oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate. 

How Are Antioxidants Different Than Sunscreens?

Rather than react with the UV rays, antioxidants destroy free radicals, or rather, they absorb free radicals offering protection from indirect DNA damage by soaking up free radicals.

While physical and chemical sunscreens are most effective sitting on the surface of your skin and work by blocking UV rays (physical sunscreens) or reacting with UV rays to form something else (chemical sunscreens), antioxidants protect your body from the effects of UV rays, specifically free radicals. 

I mentioned earlier, but it’s worth mentioning again:  chemical and physical sunscreens are designed to sit on the surface of your skin.  That’s where they’re most protective for your skin.  However, chemical sunscreens are often absorbed into the skin and nano-particle physical sunscreens have also been shown to absorb into the skin, and that’s a problem.


While it's one thing for chemical sunscreens to generate free radicals when they're sitting on your skin's surface, it's quite another for them to generate free radicals in your living skin layers.  Multiple studies show that chemical sunscreens actually increase the amount of free radicals in skin tissue, and this is why I avoid them.

Physical sunscreens are a definitely a better option,... at least at face value.  While physical sunscreens technically work by reflecting UV light back off your skin, I didn’t mention the rest of the story. 

Zinc oxide and titanium dioxide can also react with UV rays, just like chemical sunscreens, and just like chemical sunscreens, these physical sunscreens can also generate free radicals and other reactive oxygen species (ROS) when they react with UV light, and while that’s fine sitting on the surface of your skin, it’s not what you want going on in your living skin layers. 

Back in 2013, my husband used this concept in a manufacturing process he was working on.  Seeing the effects in person (we were both working for the same company at the time), I was so appalled I stopped wearing make-up. He got a patent out of the deal.

Now, I understand that's a bit extreme, but there's also no escaping titanium dioxide and other metal oxides like iron oxide in make-up, and to my knowledge, no company claims non-nano or non-micronized titanium dioxide or iron oxides in make-up.  I will occasionally wear lipstick, but I've developed such an aversion to foundation, blush, and eyeshadow that I just can't bring myself to wear those anymore.

Moving back into today's topic, if you opt for a physical sunscreen, non-nano is the best choice, just embrace the white film.

Okay, so, what about antioxidants?

Antioxidants are kind of like a sponge, they soak up free radicals near them, but they can only soak up so many before they become saturated and have to be rejuvenated (or like a sponge, squeezed out & dried) before they can soak up more free radicals.  Many anti-oxidants help rejuvenate each other. 

For example, glutathione, a naturally occurring antioxidant in the body, can rejuvenate a Vitamin C molecule that’s spent (technical word for this is oxidized) converting it back to its antioxidant state so that it can soak up more free radicals.

And, many antioxidants also naturally occur within your body.  Coenzyme Q-10, melanin, alpha lipoic acid, and glutathione are all made by your body.  Vitamins C & E are common in foods.

The beauty of your body making its own antioxidants and getting antioxidants in your diet is that these antioxidants are available to help protect skin cells from free radical damage (the effects of UV) when you’re out in sunlight.

However, since these antioxidants can be rapidly depleted when you’re bombarded with sunlight AND because antioxidants do not offer protection against direct UV damage to DNA, it’s important to:

  • apply antioxidants topically & frequently when outdoors
  • use photoprotective clothing or non-nano physical sunscreens

Why antioxidants don't have SPF Ratings

Lastly, if you’ve ever wondered why products containing antioxidants don’t list an SPF (sun protection factor), here’s why:  since antioxidants don’t technically block UV rays, you won’t find a sun protection factor (SPF) listed on products rich in antioxidants.  Antioxidants only protect from the effects of UV and don’t stop UV rays from penetrating your skin. 

What's the deal with SPF?

No conversation on sunscreen would be complete without talking about SPF and what it means.  SPF only applies to UVB rays and not UVA rays unless the sunscreen specifies broad spectrum.

what SPF means comparing SPF 15 vs. SPF 30

Which is better? Antioxidants or sunscreens?

I really feel the choice of sunscreen, antioxidants, or both is one you have to make for yourself, and above all, protective clothing and shade is hands down THE best choice. 

I always like to couple protective clothing and shade with antioxidant protection, but again, that’s me, and don’t be surprised if you see a future post about the best non-nano physical sunscreens just in case you choose to incorporate sunscreens into your sun protection.

Want to check out more posts in this series?

      Brandy Searcy founder Rain Organica

      About the Author

      Brandy's a formulation scientist and self-proclaimed health geek who loves hiking, gardening, bird-watching, and body boarding. 

      Her struggle with acne during her teens and 20s led to a holistic and healthy approach to skincare, embracing skin as an organ to be loved and cared for rather than a canvas to wage war on. 

      Since 2008, she's been developing all-in-one products for a simple routine at home, & Rain Organica started when her backpacking friends asked for a portable skincare routine to keep their skin healthy & happy on and off the trails.

      You can try Rain Organica for yourself with The Essentials Kit, a complete skincare routine in just 3 steps.

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