Zinc Oxide in Skincare: What It Does and Who It Suits
Zinc oxide is a white mineral powder that sits on the skin and scatters UV light, which is why it is a long-standing sunscreen ingredient. It is also used for its soothing, skin-protecting feel in creams and balms, and it is gentle enough for many reactive skin types.
TL;DR
- What it is: a mineral powder used as a UV filter and a skin protectant.
- How it works: it sits on the surface and reflects and absorbs UV rays instead of soaking in.
- Nano worry: the TGA's review found nano zinc oxide stays in the outer skin layer and does not reach living skin cells.
- The trade-off: a visible white cast and a thicker feel, depending on the formula.
- Avoid sprays: EU rules bar nano zinc oxide in products that could be inhaled.
- Our position: it is not in any of our formulas, and a moisturiser is not a sunscreen.
What is zinc oxide?
Zinc oxide is an inorganic mineral, a fine white powder made from zinc and oxygen. In skincare it is used as a colourant, a skin protectant and, most famously, a mineral UV filter.
It is what gives mineral sunscreens their chalky look and nappy rash creams their thick, white texture. Its mineral partner in many sunscreens is titanium dioxide.
How does zinc oxide work in sunscreen?
It is a physical, or mineral, filter. Instead of dissolving into skin, it forms a layer on top that scatters and absorbs UV light.
That makes it popular for people who find chemical filters irritating. Many people also like that it feels less likely to sting.
What is nano zinc oxide?
Nano zinc oxide is the same mineral milled into much smaller particles. The smaller size cuts the white cast, so the sunscreen rubs in clearer.
The size is also what raises the question about whether the particles can get into skin.
Does nano zinc oxide go through the skin?
The evidence says very little does. Australia's Therapeutic Goods Administration reviewed the literature and concluded that the weight of evidence suggests titanium dioxide and zinc oxide nanoparticles do not reach viable skin cells.
The review did note caveats. Some studies used hairless mice, which are more permeable than human skin, and a few detected trace particles in deeper tissue.
What are the rules on zinc oxide in cosmetics?
The EU allows nano zinc oxide as a UV filter up to 25% in the finished product. It sets purity and particle size requirements for the material.
The same regulation bars its use in any application that could expose the lungs by inhalation, which rules out sprays and powders you could breathe in.
Who suits zinc oxide?
People with sensitive or reactive skin often tolerate zinc oxide well, because it sits on the surface and does not rely on chemical filters. It is worth trying if other sunscreens sting.
It can feel heavy and leave a cast, especially on deeper skin tones. Try a formula with a tint or a lighter texture.
Does zinc oxide in a moisturiser protect you from the sun?
Not on its own. A moisturiser that lists zinc oxide is not the same as a sunscreen, because protection depends on the amount, the formula and how thickly you apply it.
If sun protection is the goal, use a product sold and labelled as a sunscreen. Our piece on causes of skin damage covers how sun fits into the bigger picture.
How do you use zinc oxide?
Apply sunscreen generously and evenly, and follow the directions on the label. Patch test any new product first, as our guide to patch testing explains.
At night, cleanse well. Mineral sunscreens can cling, and a gentle double cleanse removes them.
Safety and typical concentration range
For nano zinc oxide, EU rules cap the amount at 25% in the ready-to-use product, and the material must meet set purity and particle size standards. The TGA's literature review concluded that neither titanium dioxide nor zinc oxide nanoparticles are likely to cause harm when used as sunscreen ingredients.
In skin-protectant balms and creams the amount varies by product, so check the label.
Do we use zinc oxide at Dope Skin Co?
No. Zinc oxide is not in any of our current formulas, and we do not sell a sunscreen.
If you like mineral ingredients, kaolin clay is in our Acai Purifying Clay Mask. If you want help building a routine, take the skincare quiz.
FAQ
Is zinc oxide safe for sensitive skin?
Many people with sensitive skin tolerate it well, since it stays on the surface. As with any product, patch test first.
Is zinc oxide a chemical or mineral sunscreen?
It is a mineral, or physical, filter.
Why does zinc oxide leave a white cast?
The particles reflect visible light as well as UV. Nano and tinted versions reduce the effect.
Can zinc oxide clog pores?
The ingredient itself is a mineral powder, not an oil. How a sunscreen behaves on your skin depends on the whole formula.
