Cited skincare — every flag names its source, no upsell.Is
Iscotrizinol
Diethylhexyl Butamido TriazoneSPF filter
An oil-soluble UVB filter that holds up in sunlight — cleared in the EU, Australia, and Japan, but not the US.
What it does
It’s a chemical UVB filter that holds up in sunlight. It dissolves in oil, so it suits rich or water-free sunscreens. It’s approved in the EU, Australia and Japan but not the US, and is often paired with bemotrizinol and avobenzone.
The EU’s ingredient database lists it as a UV filter (filters UV rays) and a light stabilizer (protects the product from light).European Commission, CosIng (© European Union, CC BY 4.0) · uses put in plain words by Drop ↗
The evidence, graded
expert consensusSunscreen is the final leave-on step of the morning. The SPF number on the bottle comes from testing that product on its own, spread evenly at 2 mg/cm², with nothing layered over it — so once something goes on top, the label no longer describes what is on the skin. No study Drop has read measured how much protection a layer on top costs.Petersen 2014 · Photodermatology, Photoimmunology & Photomedicine ↗ expert consensusReapply sunscreen at least every two hours during sun exposure, and immediately after swimming, sweating, or towel-drying. One of the reviews behind this advises going sooner: Petersen and Wulf suggest a second coat within the first hour, because the first coat is almost always thinner than the amount the SPF number was measured on.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.
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