What it is
Bemotrizinol is an oil-soluble organic compound with the molecular formula C38H49N3O5, added to sunscreens to absorb ultraviolet light across a broad range, with two absorption peaks reported at about 310 and 340 nanometers covering both UVB and UVA wavelengths. It is notably photostable: cosmetics references report that even after 50 minimal erythemal doses of exposure about 98.4 percent of the molecule remains intact. Beyond protecting skin directly, it can help stabilize other sunscreen actives such as avobenzone against breakdown in light. A water-dispersible version suspends the filter in a PMMA matrix dispersed in water for use in lighter, more aqueous formulas.
Spectrum coverage
UVA1 · UVA2 · UVB
Regional approval · max %
Safety & warnings
Bemotrizinol is generally regarded as a well-tolerated modern UV filter. Unlike some older organic sunscreen ingredients, cosmetics and chemistry references report that it shows no estrogenic effects in laboratory in vitro testing, and its large, photostable molecule is associated with low skin penetration.
Origin & sourcing
Bemotrizinol is a synthetic triazine-class UV filter produced for cosmetic use; it is not found in nature. It is marketed under several trade names, including Tinosorb S, Escalol S, and Parsol Shield, and BASF developed a water-dispersible grade sold as Tinosorb S Aqua.
History
Bemotrizinol has been approved for use in sunscreens in the European Union since 2000 and is also permitted in markets such as Australia. In June 2026 it was approved for use in sunscreens in the United States, expanding the set of countries where it can be sold in over-the-counter sun products.
Questions everyone asks
What kind of UV protection does bemotrizinol give?
It is a broad-spectrum organic filter that absorbs both UVA and UVB, with reported absorption peaks near 310 and 340 nanometers.
Is bemotrizinol photostable?
Yes. References report it stays largely intact under heavy sun exposure and can also help protect other filters such as avobenzone from breaking down.
Is it approved in the United States?
It has long been approved in the EU since 2000, and as of June 2026 it was approved for use in sunscreens in the United States.