Tinosorb M: The Filter That Both Absorbs and Reflects
A hybrid filter that breaks the chemical-vs-mineral binary.
Tinosorb M (bisoctrizole) is permitted in the EU at up to 10% and is highly photostable, helping stabilize other filters in the formula.
Because Tinosorb M is a microfine particle dispersion, it acts like a hybrid — absorbing UV like a chemical filter while also scattering it like a mineral one.
Questions we get a lot
What is Tinosorb M (bisoctrizole)?
Tinosorb M is BASF's trade name for bisoctrizole, a broad-spectrum UVA+UVB filter delivered as microfine organic particles dispersed in water. Unusually, it works by both absorbing and scattering UV — part chemical, part physical — which is why it's described as a hybrid filter.
Why isn't Tinosorb M in US sunscreens?
The US regulates sunscreens as OTC drugs, and the FDA has not approved bisoctrizole (Tinosorb M) for use in sunscreens sold here. It's common across the EU, Japan and Korea, but remains under FDA review, so American sunscreens can't legally include it yet.
Does Tinosorb M leave a white cast?
It can leave a faint cast. Because it's a particulate filter that scatters some visible light, high-percentage formulas may look slightly whitish, similar to a light mineral sunscreen — though usually far less than zinc oxide. Tinted or well-formulated versions minimize it.
r/SkincareScience: 'Is Tinosorb M considered a chemical or a mineral sunscreen?'