Chemical vs. Mineral Sun Protection: What's Actually on Your Skin

Most people never think about how their sunscreen actually works. It's just the stuff you put on before you go outside. But there are two completely different ways a sun block can protect you — and the difference comes down to something surprisingly simple: where the product goes once it's on your skin.

Two kinds of sun block

Broadly, sun blocks fall into two camps: chemical and mineral.

Chemical sun blocks work by soaking into your skin and absorbing UV rays, converting them into heat that your skin releases. To do that, the active ingredients have to penetrate — that's the whole mechanism. Mineral sun blocks work the opposite way. The active ingredients, zinc oxide and titanium dioxide, sit on the surface of your skin and form a physical barrier that stops UV before it ever gets in.

Same goal. Very different approach. And that difference matters more than most people realize.

Chemical filters end up in your bloodstream

This isn't a fringe claim — it's the FDA's own finding. In a 2020 randomized clinical trial published in JAMA, the FDA tested common chemical sunscreen ingredients and found that all six were absorbed into the bloodstream at concentrations that exceeded the agency's own threshold for requiring further safety review — after just one day of normal use (Matta et al., 2020).

Now, to be clear about what that does and doesn't mean: the FDA was careful to say that being absorbed doesn't automatically make an ingredient unsafe, and that people shouldn't stop using sunscreen. The point isn't panic. The point is that when you put a chemical sun block on, those ingredients don't just stay on your skin — they end up inside you, and the long-term picture is still being studied.

Minerals stay where you put them

Zinc oxide and titanium dioxide are a different story. They're the only two sunscreen actives the FDA classifies as "generally recognized as safe and effective" — and part of the reason is that they've been shown to stay on the surface of the skin with almost no absorption into the body (Harvard Health, 2019; The Skin Cancer Foundation).

In other words, a mineral sun block does its job from the outside. It sits on top, blocks the sun, and is removed from the skin when you wash it off. There's no absorption question to worry about.

For a lot of people, that's the whole reason to choose mineral. You get real sun protection without putting anything into your body that doesn't need to be there.

So why doesn't everyone use mineral?

One reason: the white cast.

Because mineral sun blocks sit on top of your skin instead of soaking in, they can leave a pale, chalky film — that ghostly look you've probably seen (or worn). It's the single biggest complaint about mineral sunscreen, and it's why a lot of people drift back to chemical formulas that disappear on contact. Nobody wants to walk around looking like they dipped their face in flour.

That's a real problem. But it's not an unsolvable one.

How we fixed it: tint

Here's the thing — the white cast isn't a reason mineral sunscreen has to look bad. It's just a problem most brands never bothered to solve properly.

We solved it with tint. Our first product is mineral-based — zinc oxide and titanium dioxide, sitting on the surface, doing their job from the outside. But we added a warm, skin-tone adjusting tint that cancels out the white film completely. Instead of a pale cast, the product settles into your natural skin tone and disappears. Zero white cast. Full mineral protection. No harsh chemical filters soaking into your bloodstream.

That's the whole idea: you shouldn't have to choose between a sun block that's clean and one that actually looks good. The tint is what lets you have both.

The takeaway

Chemical sun blocks work by absorbing into your skin — and, as the FDA found, into your bloodstream. Mineral sun blocks stay on the surface, block the sun from the outside, and wash off when you're done. The only real knock on mineral has always been the white cast — and that's exactly the problem we built to solve. 

References

1. Matta MK, Florian J, Zusterzeel R, et al. Effect of sunscreen application on plasma concentration of sunscreen active ingredients: a randomized clinical trial. JAMA. 2020;323(3):256–267. doi:10.1001/jama.2019.20747
2. Harvard Health Publishing. Keep using sunscreen while FDA updates recommendations on safety of sunscreen ingredients. Harvard Health Blog. 2019.
3. The Skin Cancer Foundation. What's the sunscreen situation?