Chemical filter

Mexoryl XL

Photostable oil-soluble UVA+UVB filter used with Mexoryl SX. Australia allows 10%. Long international use without a major systemic signal.

Drometrizole trisiloxane is a lipophilic benzotriazole filter with peaks around 303 nm and 344 nm. The siloxane tail makes it compatible with silicone oils. L’Oréal markets it as Mexoryl XL, usually paired with water-soluble Mexoryl SX.

Australia’s TGA Table 9 (August 2025) lists a 10% maximum for listed therapeutic sunscreens. The EU cap is higher at 15%. It is not a US OTC-monograph active.

It is a large lipophilic molecule with low expected skin penetration and a long record of international use. Contemporary standalone human toxicology is thinner than for bemotrizinol, but there is no major current systemic safety signal.

Sources

Sunscreens with Mexoryl XL

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