Oc
Octisalate
Ethylhexyl SalicylateSPF filter
A UVB sunscreen filter. It doesn’t do much alone, but it helps keep avobenzone from breaking down in sunlight.
What it does
On its own it doesn’t add much SPF; in products it’s mostly a second filter that helps keep avobenzone from breaking down in sun.
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 ↗
expert consensusSunscreen works best as its own film on top of moisturizer rather than mixed into it in your palm. The SPF on the label was measured on the product as sold, applied at 2 mg/cm². Blend it with something else and there is less sunscreen over the same area, so the label's number no longer describes the film. No study Drop has read measured how far the protection falls.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
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