Meet Tinosorb S, the Filter the Rest of the World Has Loved for 20 Years
Broad-spectrum, photostable, and finally US-bound.
Tinosorb S (bemotrizinol) is a broad-spectrum UVA+UVB filter that has been used in Europe and Asia since the early 2000s and is highly photostable.
Cosmetic chemists value Tinosorb S because it absorbs across both UVA and UVB while staying photostable, so its protection does not collapse in sunlight the way avobenzone's can.
Questions we get a lot
What is Tinosorb S and is it the same as bemotrizinol?
Yes — Tinosorb S is the trade name for bemotrizinol (also sold as Parsol Shield), a broad-spectrum filter that absorbs both UVA and UVB and is highly photostable. It has been used in European and Asian sunscreens for around two decades and was approved for US use by the FDA in 2026.
Are next-gen UV filters better than older ones?
Newer filters such as bemotrizinol, bisoctrizole and Mexoryl 400 generally give broader, more even UVA coverage and far better photostability than older ones like avobenzone, which degrades in sunlight. They also tend to feel more elegant — though applying enough and reapplying still matter most.
Why does photostability matter in a sunscreen?
A photostable filter keeps absorbing UV without breaking down in sunlight, so protection lasts through wear. Older filters like avobenzone can lose effectiveness within an hour unless stabilized, whereas Tinosorb S stays chemically stable — one reason it is so widely used abroad. Reapplication is still advised.
r/SkincareScience: 'Is Tinosorb S really the same thing as bemotrizinol?'