Ingredient glossary
Zinc Oxide
On your shelf ✓What Zinc Oxide does for your skin, who it suits, and what to watch for.
INCI: Zinc Oxide · Also: ZnO
In short: Zinc Oxide delivers uvb uva protection and anti inflammatory, suits most skin types, and the evidence behind it is strong.
- What it does
- Uvb uva protection, anti inflammatory
- Best for
- Most skin types
- Evidence
- Strong
- How long
- Straight away
how it was measured
Measured on UV attenuation by the applied film - in vivo SPF and UVA protection factor; the clinical consensus; no trial pins the point.
The molecule
Zinc Oxide is not a molecule at all. It is an ionic solid, the same ions repeating in a lattice, so there is nothing here to join with a line.
The Glow take
Only as good as the sunscreen it lives in.
As a single filter, Zinc Oxide only matters as part of a finished sunscreen you actually reapply. The best SPF is the one that feels good enough to wear every morning.
— Maya
What it does
- uvb uva protection
- anti inflammatory
strong evidenceThe EU (SCCS/1489/12; Annex VI entries 30 and 30a) and the US OTC sunscreen monograph both permit zinc oxide as a UV filter at up to 25%.
Why we say this
- That 25% is a safety ceiling for use on skin, not a dose shown to outperform a lower one, and the EU excludes anything that could reach the lungs by inhalation — sprays are out.
- Skin penetration and systemic absorption are negligible and irritation is low; the "photostable" label traces to older manufacturer work on a branded grade rather than to the regulatory review.
- SCCS/1489/12 (EU Scientific Committee opinion)
- SCCS/1518/13 (EU Scientific Committee opinion)
- 21 CFR 352.10(r) (US federal regulation)
- PMID 24198489 · read in full
- PMID 30448212 · abstract
On a label: usually effective at 5-25%.
The mineral UV filter family, at a glance
2 mineral UV filter entries in the base, Zinc Oxide among them. 2 of the 2 are a hero active.
- Titanium Dioxide80 Da
- Zinc Oxide81 Da
Who it's for, and who should skip it
Tends to suit
- all
- sensitive
- acne prone
- rosacea prone
Approach with care
No specific group flagged to avoid it.
- Clogs poresLow
- Irritation riskLow
How it fits each skin type
- DrySuits
- CombinationSuits
- OilySuits
- SensitiveSuits
Often chosen for acne prone, rosacea prone.
Where it fits in your routine
This one works on contact — there is nothing to wait for.
What that covers, and what it does not
- Measured on: UV attenuation by the applied film — in vivo SPF and UVA protection factor.
- Protection is a property of the dried film rather than a change in the skin: ISO 24444 in vivo SPF testing irradiates 15-30 minutes after a 2 mg/cm2 application, which is drying time, and US labelling (21 CFR 201.327) directs application 15 minutes before exposure.
- Permitted to 25% in both the US OTC monograph and EU Annex VI (entries 30/30a) — a safety ceiling, not a demonstrated optimum dose.
- Two other outcomes the base credits are on different clocks and are not what this row times: photoaging prevention, which in the Nambour randomised trial of daily broad-spectrum sunscreen took 4.5 years to register on skin microtopography, and the anti-inflammatory/acne credit, for which no timed human data exist.
ISO 24444:2019 in vivo SPF method; US 21 CFR 201.327; EU Reg 1223/2009 Annex VI entries 30/30a. Photoaging clause: Hughes et al., Annals of Internal Medicine 2013, Nambour daily-sunscreen randomised trial (no PMID quoted).
Light, and how to keep it
Zinc Oxide does not break down in light, which is worth saying because plenty of people assume it does.
how it was measured
It was concluded by the applicant that all three model O/W formulations with uncoated (Z-COTE) and coated (Z-COTE HP1, Zano 10 Plus) ZnO were photostable over the whole UV range between 290 and 400 nm.SCCS/1489/12(full)
measured stable in light
Where this filter sits on the ladder of what fails first in an ageing sunscreen: does sunscreen expire?
What regulators say
In the EU zinc oxide is capped at 25% as a UV filter (Annex VI entry 30, and entry 30a for the nano form); not in sprays that reach the lungs.
What the regulator says, in full
- A UV filter has no dose-effect relationship worth stating for one ingredient: the number a reader can use is the product's SPF and UVA rating, measured on the finished film by ISO 24444 and ISO 24443, and it depends on the whole filter system, the film thickness and the vehicle, not on the percentage of zinc oxide alone.
- The regulators set ceilings for safety, not efficacy: EU Annex VI entries 30 and 30a, 25% (Regulation 2016/621); 21 CFR 352.10, up to 25%.
- Above those limits nothing is permitted and below them the SPF is whatever the product's own test says.
- The caveat: the SCCS opinions SCCS/1489/12 and SCCS/1518/13 cover the nano form.
Plays well with
- other uv filters
- antioxidants
Zinc Oxide, answered
Is Zinc Oxide safe during pregnancy?
Yes. Zinc Oxide is considered safe to use during pregnancy and breastfeeding. As with anything, if you are unsure it is worth a quick word with your doctor or midwife.
Who should avoid Zinc Oxide?
No specific group is flagged to avoid Zinc Oxide. It is well tolerated by most skin. Still, introduce anything new one product at a time.
What concentration of Zinc Oxide actually works?
Zinc Oxide tends to do its job in the 5 to 25% range. Much lower and it is likely underdosed.
Does Zinc Oxide break down in the light?
No, and it is worth saying because plenty of people assume it does. It was concluded by the applicant that all three model O/W formulations with uncoated (Z-COTE) and coated (Z-COTE HP1, Zano 10 Plus) ZnO were photostable over the whole UV range between 290 and 400 nm.
Can you mix Zinc Oxide with
1 pairing built.
This, for every label you own
One ingredient is easy. A full label is where it gets confusing. The Ingredient Decoder reads any product and tells you the honest truth, ingredient by ingredient.
Sources & how we reviewed this
- SCCS/1489/12 (EU Scientific Committee opinion)read in full
- SCCS/1518/13 (EU Scientific Committee opinion)read in full
- 21 CFR 352.10(r) (US federal regulation)read in full
- PMID 24198489read in full
- PMID 30448212abstract read, not the full text
What changed on this page
- : the effective dose from trials, the highest dose tested
- : light stability
- : what the EU regulates