Zi
Zinc Oxide (sunscreen)
Zinc OxideSPF filter
Mineral UV filter. Broadest-spectrum single filter available; physical sunscreen workhorse.
What it does
Zinc oxide reflects and absorbs UVA + UVB. The most reliably broad-spectrum mineral filter. Modern formulations grind it small enough to reduce the white cast historically associated with mineral SPF; nano-zinc remains a topic of formulation debate but is considered safe by most regulatory bodies.
The evidence, graded
strongAntioxidants neutralize free radicals generated by the UV that gets through sunscreen. Layering an antioxidant serum under SPF compounds photoprotection.Wu 2011 · Clinical and Experimental Dermatology ↗
expert consensusSunscreen should sit as a film on top of moisturizer, not be mixed into it. Diluting sunscreen with moisturizer in your hand reduces filter concentration and the labeled SPF no longer applies.Petersen 2014 · Photodermatology, Photoimmunology & Photomedicine ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Pairs worth knowing
This page is public and indexed on purpose (unlike profiles and drops, which are unlisted) — it’s the citation behind shared ingredient cards, and it should be findable.
Want more like this?
Get Drop, free. Every flag cites its source, the app tells you when your routine is complete, and it helps you simplify — instead of selling you more products.